Lobeglitazone (trade name Duvie, Chong Kun Dang) is an antidiabetic drug in the thiazolidinedione class of drugs. As an agonistfor both PPARα and PPARγ, it works as an insulin sensitizer by binding to the PPAR receptors in fat cells and making the cells more responsive to insulin.^[3]

Chong Kun Dang

Lobeglitazone sulfate was approved by the Ministry of Food and Drug Safety (Korea) on July 4, 2013. It was developed and marketed as Duvie^® by Chong Kun Dang Corporation.

Lobeglitazone is an agonist for both PPARα and PPARγ, and it works as an insulin sensitizer by binding to the PPAR receptors in fat cells and making the cells more responsive to insulin. It is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes.

Duvie^® is available as tablet for oral use, containing 0.5 mg of free Lobeglitazone. The recommended dose is 0.5 mg once daily.

Lobeglitazone which was reported in our previous works belongs to the class of potent PPARα/γ dual agonists (PPARα EC₅₀:  0.02 μM, PPARγ EC₅₀:  0.018 μM, rosiglitazone; PPARα EC₅₀:  >10 μM, PPARγ EC₅₀:  0.02 μM, pioglitazone PPARα EC₅₀:  >10 μM, PPARγ EC₅₀:  0.30 μM). Lobeglitazone has excellent pharmacokinetic properties and was shown to have more efficacious in vivo effects in KKA^y mice than rosiglitazone and pioglitazone.¹⁷ Due to its outstanding pharmacokinetic profile, lobeglitazone was chosen as a promising antidiabetes drug candidate.

Medical uses

Lobeglitazone is used to assist regulation of blood glucose level of diabetes mellitus type 2 patients. It can be used alone or in combination with metformin.^[4]

Lobeglitazone was approved by the Ministry of Food and Drug Safety (Korea) in 2013, and the postmarketing surveillance is on progress until 2019.^[4][5]

SYNTHESIS

Chong Kun Dang’s Modcol Flu Dry Syrup is released in four different versions: All-Day, Night, Nose and Cough. [CHONG KUN DANG]

PAPER

Org. Process Res. Dev. 2007, 11, 190-199.

Process Development and Scale-Up of PPAR α/γ Dual Agonist Lobeglitazone Sulfate (CKD-501)

http://pubs.acs.org/doi/abs/10.1021/op060087u

A scaleable synthetic route to the potent PPARα/γ dual agonistic agent, lobeglitazone (1), used for the treatment of type-2 diabetes was developed. The synthetic pathway comprises an effective five-step synthesis. This process involves a consecutive synthesis of the intermediate, pyrimidinyl aminoalcohol (6), from the commercially available 4,6-dichloropyrimidine (3) without the isolation of pyrimidinyl phenoxy ether (4). Significant improvements were also made in the regioselective 1,4-reduction of the intermediate, benzylidene-2,4-thiazolidinedione (10), using Hantzsch dihydropyridine ester (HEH) with silica gel as an acid catalyst. The sulfate salt form of lobeglitazone was selected as a candidate compound for further preclinical and clinical study. More than 2 kg of lobeglitazone sulfate (CKD-501, 2) was prepared in 98.5% purity after the GMP batch. Overall yield of 2 was improved to 52% from 17% of the original medicinal chemistry route.

Silica gel TLC R_f = 0.35 (detection:  iodine char chamber, ninhydrin solution, developing solvents:  CH₂Cl₂/MeOH, 20:1); mp 111.4 °C; IR (KBr) ν 3437, 3037, 2937, 2775, 1751, 1698, 1648, 1610, 1503, 1439, 1301, 1246, 1215, 1183 cm^-1;

¹H NMR (400 MHz, CDCl₃) δ 3.09 (m, 4H), 3.29 (m, 1H), 3.76 (s, 3H), 3.97 (m, 2H), 4.14 (m, 2H), 4.86 (m, 1H), 6.06 (bs, 1H), 6.86 (m, 2H), 7.00 (m, 2H), 7.13 (m, 4H), 8.30 (s, 1H), 11.99 (s, NH);

¹³C NMR (100 MHz, CDCl₃) δ 37.1, 38.2, 53.7, 53.8, 56.3, 62.2, 65.8, 86.0, 115.1, 116.0, 123.0, 129.8, 131.2, 145.7, 153.4, 157.9, 158.1, 161.1, 166.5, 172.4, 172.5, 176.3, 176.5;

MS (ESI)m/z (M + 1) 481.5; Anal. Calcd for C₂₄H₂₆N₄O₉S₂:  C, 49.82; H, 4.53; N, 9.68; S, 11.08. Found:  C, 49.85; H, 4.57; N, 9.75; S, 11.15.

PATENT

WO03080605A1.

Clip
Lobeglitazone sulfate (Duvie) Lobeglitazone sulfate, an oral peroxisome proliferator-activated receptor (PPARa/c) dual agonist with IC50 = 20 and 18 nM respectively, was developed by Chong Kun Dang Pharmaceutical in Korea for the treatment of diabetes.135 This drug is differentiated from two other PPAR agonists available—pioglitazone and rosiglitazone —which lack PPARa activity.135 The most likely processscale preparation of lobeglitazone sulfate follows the route described in a process communication from Chong Kun Dang Pharmaceutical.136

Commercially available 4,6-dichloropyrimidine (152) was treated with a stoichiometric equivalent of p-methoxyphenol (153) in the presence of KF in warm DMF (Scheme 24). Upon completion of this reaction, 2-methylaminoethanol was added to the mixture to provide pyrimidine 154 in high yield.137

Next, alcohol 154 underwent a substitution reaction with p-fluorobenzaldehyde (155) under basic conditions to provide alkoxy benzaldehyde 156 which was converted to the benzylidene thiazolidindione 158 upon subjection to Knoevenagel conditions with 2,4-thiazolidinedione (157) in 90% yield.

Finally, reduction of olefin 158 was facilitated by treatment with the Hantzsch ester (159) in the presence of silica gel followed by treatment with methanolic sulfuric acid (96%) at low temperature to ultimately furnish lobeglitazone sulfate in 90% yield.

135. Jin, S. M.; Park, C. Y.; Cho, Y. M.; Ku, B. J.; Ahn, C. W.; Cha, B.-S.; Min, K. W.;Sung, Y. A.; Baik, S. H.; Lee, K. W.; Yoon, K.-H.; Lee, M.-K.; Park, S. W. Diab.Obes. Metab. 2015, 17, 599.
136. Lee, H. W.; Ahn, J. B.; Kang, S. K.; Ahn, S. K.; Ha, D.-C. Org. Process Res. Dev.2007, 11, 190.
137. Lee, H. W.; Kim, B. Y.; Ahn, J. B.; Kang, S. K.; Lee, J. H.; Shin, J. S.; Ahn, S. K.; Lee,S. J.; Yoon, S. S. Eur. J. Med. Chem. 2005, 40, 862.

References

Lobeglitazone

Systematic (IUPAC) name
5-[(4-[2-([6-(4-Methoxyphenoxy)pyrimidin-4-yl]-methylamino)ethoxy]phenyl)methyl]-1,3-thiazolidine-2,4-dione
Clinical data
Trade names	Duvie
Routes of administration	Oral
Legal status
Legal status	Rx-only in South Korea
Pharmacokinetic data
Protein binding	>99%[1]
Metabolism	liver (CYP2C9, 2C19, and 1A2)[1]
Biological half-life	7.8–9.8 hours[2]
Identifiers
CAS Number	607723-33-1
PubChem	CID 9826451
DrugBank	DB09198
ChemSpider	8002194
Synonyms	CKD-501
Chemical data
Formula	C24H24N4O5S
Molar mass	480.53616 g/mol
SMILES CN(CCOC1=CC=C(C=C1)CC2C(=O)NC(=O)S2)C3=CC(=NC=N3)OC4=CC=C(C=C4)OC

Identifications:

Experimental: ¹H NMR (400 MHz, CDCl₃) δ 3.12 (m, 4H), 3.45 (m, 1H), 3.83 (s, 3H), 4.00 (m, 2H), 4.16 (m, 2H), 4.50 (m, 1H), 5.84 (bs, 1H), 6.83 (m, 2H), 7.06 (m, 2H), 7.15 (m, 2H), 8.31 (s, 1H), 8.89 (bs, NH).

///Lobeglitazone Sulfate, CKD-501, Duvie^®,  Approved KOREA, Chong Kun Dang, A dual PPARα and PPARγ agonist , type 2 diabetes, CKD 501, 763108-62-9, 607723-33-1, IDR-105

CN(CCOC1=CC=C(C=C1)CC2C(=O)NC(=O)S2)C3=CC(=NC=N3)OC4=CC=C(C=C4)OC.OS(=O)(=O)O

AZD3514; AZD 3514; AZD-3514.

CAS 1240299-33-5
Chemical Formula: C25H32F3N7O2
Exact Mass: 519.25696

1-(4-(2-(4-(1-(3-(trifluoromethyl)-7,8-dihydro-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)piperidin-4-yl)phenoxy)ethyl)piperazin-1-yl)ethanone

Ethanone, 1-[4-[2-[4-[1-[7,8-dihydro-3-(trifluoromethyl)-1,2,4-triazolo[4,3-b]pyridazin-6-yl]-4-piperidinyl]phenoxy]ethyl]-1-piperazinyl]

6-f4-{4-[2-f4-acetylpiperazin-l-yl)ethoxylphenyl}piperidin-l-yl)-3-( trifluoromethyr)-7,8-dihvdro [ 1 ,2,41 triazolo [4,3-bl pyridazine

6-(4-{4-[2-(4-acetylpiperazin-l- vDethoxyl phenyllpiperidin- l-vD-3-f trifluoromethyl)-7.,8-(iihv(iro [ 1 ,2,41 triazolo [4,3- blpyridazine

• 1-[4-[2-[4-[1-[7,8-Dihydro-3-(trifluoromethyl)-1,2,4-triazolo[4,3-b]pyridazin-6-yl]-4-piperidinyl]phenoxy]ethyl]-1-piperazinyl]ethanone

• Originator AstraZeneca
• Class Antineoplastics
• Mechanism of Action Androgen receptor antagonists

AZD-3514 is a potent androgen receptor downregulator with potential anticancer cancer activity. AZD3514 is being evaluated in a Phase I clinical trial in patients with castrate-resistant prostate cancer.

AZD3514 is currently in Phase I trail. This trial is looking at a new drug called AZD3514 for men who have prostate cancer that has spread to other parts of the body and is no longer responding to hormone therapy.  Doctors often use hormone therapy to treat prostate cancer. This may keep it under control for long periods of time. But researchers are looking for treatments that will help men who have prostate cancer that stops responding to hormone therapy.  Prostate cancer needs the hormone testosterone to grow. The testosterone locks into receptors on the cancer cells. AZD3514 works by breaking down these receptors so that testosterone canÂ’t tell the prostate cancer cells to grow.

6-(4-{4-[2-(4-Acetylpiperazin-1-yl)ethoxy]phenyl}piperidin-1-yl)-3-(trifluoromethyl)-7,8-ihydro[1,2,4]triazolo[4,3-b]pyridazine 

as a white, free flowing solid.

¹H NMR (400 MHz, CDCl3): δ 1.62 (2H, m), 1.88 (2H, m), 2.02 (3H, s), 2.49 (4H, m), 2.65 – 2.78 (5H, m), 2.94 (2H, m), 3.15 (2H, t), 3.42 (2H, m), 3.57 (2H, m), 4.03 (2H, t), 4.24 (2H, m), 6.80 (2H, d), 7.06 (2H, d);

m/z = 520 [M+H]⁺. RT = 0.87: 99% purity.

HRMS found 520.26373,

Prostate cancer is the second leading cause of death from cancer among men in developed countries, and was projected to account for 25% of newly-diagnosed cases and 9% of deaths due to cancer in the USA in 2010. The androgen receptor (AR), a ligand binding transcription factor in the nuclear hormone receptor super family, is a key molecular target in the etiology and progression of prostate cancer.Binding of the endogenous AR ligand dihydrotestosterone stabilizes and protects the AR from rapid proteolytic degradation. The early stages of prostate cancer tumor growth are androgen dependent and respond well to androgen ablation,  either via surgical castration or by chemical castration with a luteinizing hormone releasing hormone agonist in combination with an AR antagonist, such as bicalutamide.

Although introduction of androgen deprivation therapy represented a major advance in prostate cancer treatment, recurrence within 1–2 years typically marks transition to the so-called castrate-resistant state, in which the tumor continues to grow in the presence of low circulating endogenous ligand and is no longer responsive to classical AR antagonists. Castrate-resistant prostate cancer (CRPC) is a largely unmet medical need with a 5-year survival rate of less than 15%. Antimitotic agents docetaxel and cabazitaxel, testosterone biosynthesis inhibitor abiraterone acetate and second generation AR antagonist enzalutamide (MDV3100) are the currently approved small-molecule drugs that have been shown to provide survival benefit.

Recent evidence from both pre-clinical and clinical studies is consistent with the importance of re-activation of AR signaling in a majority of castrate-resistant prostate tumors. It is also well established that the functional AR in castrate-resistant tumors is frequently mutated or amplified, and that over-expression can convert hormone-responsive cell lines to hormone refractory. Recent second-generation AR antagonists have been designed that retain antagonism in over-expressing cell lines, and among these agents enzalutamide has recently successfully met efficacy criteria in a large Phase III clinical trial.

By analogy with fulvestrant, an estrogen receptor (ER) downregulator approved by the FDA in 2002 for treatment of advanced breast cancer and initially characterized as a pure ER antagonist, a ligand which downregulates the AR represents one of a number of potential approaches to treatment of CRPC via a sustained reduction in tumor AR content. We recently described derivation from a novel 3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazine ligand of AR inhibitor 1 The compound also causes AR downregulation¹⁵ and high plasma levels following oral administration in pre-clinical models compensate for moderate cellular potency

Figure 1.

Structures of lead AR downregulator 1 and chemotype 2.

Scheme 3.

Synthesis of compounds 10, 11a–b, 12. Reagents and conditions: (a) 2-(1-Methyl-1H-pyrazol-5-yl)ethanol,²⁷ Ph₃P, diisopropyl azodicarboxylate, THF, 20 °C; (b) 2-(4-acetylpiperazine-1-yl)ethanol,²⁸ Ph₃P, diisopropyl azodicarboxylate, THF, 20 °C; (c) H₂, 10% Pd-C, MeOH, 50 °C.

PATENT

WO 2010092371

Preparation of 6-f4-{4-[2-f4-acetylpiperazin-l-yl)ethoxylphenyl}piperidin-l-yl)-3-

( trifluoromethyr)-7,8-dihvdro [ 1 ,2,41 triazolo [4,3-bl pyridazine

A solution of acetyl chloride (0.027 mL, 0.38 mmol) in DCM (0.5 mL) was added dropwise to 6-[4- [4- [2-(piperazin- 1 -yl)ethoxy]phenyl]piperidin- 1 -yl] -3 -(trifluoromethyl)- 7,8-dihydro-[l,2,4]triazolo[4,3-b]pyridazine (150 mg, 0.31 mmol) and triethylamine (0.088 mL, 0.63 mmol) in DCM (1 mL) cooled to 0⁰C under nitrogen. The resulting solution was stirred at 0⁰C for 5 minutes then allowed to warm to room temperature and stirred for 15 minutes. The reaction mixture was diluted with water (2 mL), passed through a phase separating cartridge and then the organic layer was evaporated to afford crude product. The crude product was purified by preparative HPLC (Waters XBridge Prep Cl 8 OBD column, 5μ silica, 19 mm diameter, 100 mm length), using decreasingly polar mixtures of water (containing 1% ammonia) and MeCN as eluents. Fractions containing the desired compound were evaporated to dryness to give 6-(4-{4-[2-(4-acetylpiperazin-l- yl)ethoxy]phenyl}piperidin-l-yl)-3-(trifluoromethyl)-7,8-dihydro[l,2,4]triazolo[4,3- b]pyridazine (80 mg, 49%) as a gum.

IH NMR (399.9 MHz, CDC13) δ 1.69 (2H, m), 1.95 (2H, m), 2.08 (3H, s), 2.56 (4H, m), 2.71 – 2.84 (5H, m), 3.00 (2H, m), 3.22 (2H, t), 3.48 (2H, m), 3.63 (2H, m), 4.10 (2H, t), 4.31 (2H, m), 6.86 (2H, d), 7.12 (2H, d); m/z = 520 [M+H]+.

The 6-[4-[4-[2-(piperazin- 1 -yl)ethoxy]phenyl]piperidin- 1 -yl]-3-(trifluoromethyl)-7,8- dihydro-[l,2,4]triazolo[4,3-b]pyridazine used as starting material was prepared as follows :-

Preparation of tert-butyl 4-[2-[4-(l-(benzyloxycarbonyl)-l,2,3,6-tetrahydropyridin-4- yl)phenoxy]ethyl]piperazine-l-carboxylate DIAD (12.60 mL, 64.00 mmol) was added dropwise to benzyl 4-(4-hydroxyphenyl)-5,6- dihydropyridine-l(2H)-carboxylate (obtained as described in Example 4.1, preparation of starting materials) (16.5 g, 53.34 mmol), tert-butyl 4-(2-hydroxyethyl)piperazine-l- carboxylate (CAS 77279-24-4) (14.74 g, 64.00 mmol) and triphenylphosphine (16.79 g, 64.00 mmol) in THF (150 mL) under nitrogen. The resulting solution was stirred at ambient temperature for 16 hours. The reaction mixture was evaporated to dryness then the residue was stirred in ether (200 mL) for 10 minutes at room temperature. The resulting precipitate was removed by filtration and discarded. The ether filtrate was washed with water (100 mL) followed by saturated brine (100 mL), then dried over MgSO4, filtered and evaporated to give crude product. The crude product was purified by flash silica chromatography, elution gradient 20 to 60% EtOAc in isohexane. Fractions containing the desired product were evaporated to dryness to afford tert-butyl 4-[2-[4-(l- (benzyloxycarbonyl)- 1,2,3, 6-tetrahydropyridin-4-yl)phenoxy]ethyl]piperazine-l- carboxylate (34.6 g, 82%) as a gum which was contaminated with 34% by weight triphenylphosphine oxide.

IH NMR (399.9 MHz, DMSO-d6) δ 1.40 (9H, s), 2.42 – 2.47 (6H, m), 2.71 (2H, m), 3.32 (4H, m), 3.62 (2H, m), 4.03 – 4.10 (4H, m), 5.12 (2H, s), 6.06 (IH, m), 6.92 (2H, d), 7.31 – 7.40 (7H, m); m/z = 522 [M+H]+.

Preparation of tert-butyl 4-[2-[4-(piperidin-4-yl)phenoxy]ethyl]piperazine-l- carboxylate tert-Butyl 4-[2-[4-(l-(benzyloxycarbonyl)-l,2,3,6-tetrahydropyridin-4- yl)phenoxy]ethyl]piperazine-l-carboxylate (66% pure by weight) (34.62 g, 43.80 mmol) and 5% palladium on carbon (50% wet) (4.47 g, 1.05 mmol) in MeOH (250 mL) were stirred under an atmosphere of hydrogen at 5 bar and 60⁰C for 4 hours. The catalyst was removed by filtration and the solvents evaporated to give crude product. The crude product was purified by flash silica chromatography, eluting with 60% EtOAc in isohexane then 15% 2M ammonia/MeOH in DCM. Pure fractions were evaporated to dryness to afford tert-butyl 4-[2-[4-(piperidin-4-yl)phenoxy]ethyl]piperazine-l-carboxylate (15.42 g, 90%) as a solid. IH NMR (399.9 MHz, CDC13) δ 1.46 (9H, s), 1.62 (2H, m), 1.81 (2H, m), 2.50 – 2.59 (5H, m), 2.73 (2H, m), 2.80 (2H, t), 3.18 (2H, m), 3.44 (4H, m), 4.09 (2H, t), 6.85 (2H, d), 7.13 (2H, d); m/z = 390 [M+H]+.

Preparation of tert-butyl 4-[2-[4-[l-(3-(trifluoromethyl)-[l,2,4]triazolo[4,3- b]pyridazin-6-yl]piperidin-4-yl]phenoxy]ethyl]piperazine-l-carboxylate

DIPEA (2.348 mL, 13.48 mmol) was added to 6-chloro-3-(trifluoromethyl)- [l,2,4]triazolo[4,3-b]pyridazine (obtained as described in Monatsh. Chem. 1972, 103, 1591) (2 g, 8.99 mmol) and tert-butyl 4-[2-[4-(piperidin-4-yl)phenoxy]ethyl]piperazine-l- carboxylate (3.68 g, 9.44 mmol) in DMF (30 mL). The resulting solution was stirred at 80⁰C for 2 hours. The reaction mixture was cooled to room temperature and the solvents evaporated to dryness. The resulting solid was triturated with water then collected by filtration, washed with ether and dried to afford tert-butyl 4-[2-[4-[l-(3-(trifluoromethyl)- [l,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4-yl]phenoxy]ethyl]piperazine-l -carboxylate (5.02 g, 97%) as a solid.

IH NMR (399.9 MHz, CDC13) δ 1.46 (9H, s), 1.76 (2H, m), 2.00 (2H, m), 2.54 (4H, m), 2.75 – 2.86 (3H, m), 3.11 (2H, m), 3.46 (4H, m), 4.11 (2H, m), 4.37 (2H, m), 6.87 (2H, d), 7.13 (3H, m), 7.92 (IH, d); m/z = 576 [M+H]+.

Preparation of tert-butyl 4-[2-[4-[l-[3-(trifluoromethyl)-7,8-dihydro-

[1 ,2,4] triazolo [4,3-b] pyridazin-6-yl)piperidin-4-yl] phenoxy] ethyl] piperazine- 1- carboxylate

10% Palladium on carbon (0.924 g, 0.87 mmol) was added to tert-butyl 4-[2-[4-[l-(3- (trifluoromethyl)-[l,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4- yl]phenoxy]ethyl]piperazine-l -carboxylate (2.5 g, 4.34 mmol) and ammonium formate (2.74 g, 43.43 mmol) in ethanol (100 mL). The resulting mixture was stirred at 78°C, with further portions of ammonium formate being added every 5 hours until the reaction was complete. The reaction mixture was cooled to room temperature and the catalyst was removed by filtration. The filtrate was evaporated to dryness, redissolved in DCM (100 mL) and the solution was washed with water (100 mL) followed by brine (50 mL), then the solvents were evaporated to afford tert-butyl 4-[2-[4-[l-[3-(trifluoromethyl)-7,8-dihydro- [l,2,4]triazolo[4,3-b]pyπdazin-6-yl)pipeπdin-4-yl]phenoxy]ethyl]piperazine-l-carboxylate (2.02O g, 81%) as a solid.

IH NMR (399.9 MHz, CDC13) δ 1.46 (9H, s), 1.69 (2H, m), 1.95 (2H, m), 2.52 (4H, m), 2.71 – 2.82 (5H, m), 3.00 (2H, m), 3.22 (2H, t), 3.45 (4H, m), 4.09 (2H, m), 4.31 (2H, m), 6.86 (2H, d), 7.12 (2H, d); m/z = 578 [M+H]+.

Preparation of 6- [4-[4- [2-(piperazin-l-yl)ethoxy] phenyl] piperidin-1-yl] -3- (trifluor omethyl)-7,8-dihydr o- [ 1 ,2,4] triazolo [4,3-b] pyridazine

TFA (10 mL) was added to tert-butyl 4-[2-[4-[l-[3-(trifluoromethyl)-7,8-dihydro- [l,2,4]triazolo[4,3-b]pyπdazin-6-yl)pipeπdin-4-yl]phenoxy]ethyl]piperazine-l-carboxylate (2.02 g, 3.50 mmol) in DCM (10 mL). The resulting solution was stirred at ambient temperature for 1 hour then added to an SCX column. The desired product was eluted from the column using 2M ammonia/MeOH and the solvents were evaporated to afford 6-[4-[4- [2-(piperazin-l-yl)ethoxy]phenyl]piperidin-l-yl]-3-(trifluoromethyl)-7,8-dihydro- [l,2,4]triazolo[4,3-b]pyridazine (1.660 g, 99%) as a solid.

IH NMR (399.9 MHz, CDC13) δ 1.68 (2H, m), 1.95 (2H, m), 2.55 (4H, m), 2.70 – 2.80 (5H, m), 2.91 (4H, m), 3.00 (2H, m), 3.22 (2H, t), 4.09 (2H, t), 4.30 (2H, m), 6.87 (2H, d), 7.11 (2H, d); m/z = 478 [M+H]+.

Example 5.2

Larger scale preparation of 6-(4-{4-[2-(4-acetylpiperazin-l- vDethoxyl phenyllpiperidin- l-vD-3-f trifluoromethyl)-7.,8-dihvdro [ 1 ,2,41 triazolo [4,3- blpyridazine

Ammonium formate (99 g, 1568.94 mmol) was added to 6-[4-[4-[2-(4-acetylpiperazin-l- yl)ethoxy]phenyl]piperidin- 1 -yl]-3-(trifluoromethyl)[ 1 ,2,4]triazolo[4,3-b]pyridazine (81.2 g, 156.89 mmol) and 10% palladium on carbon (8.35 g, 7.84 mmol) in EtOH (810 mL) under nitrogen. The resulting mixture was stirred at 70⁰C for 6 hours, then ammonium formate (50 g) was added. The mixture was stirred at 70⁰C for 2 hours then further portions of 10% palladium on carbon (8.35 g, 7.84 mmol) and ammonium formate (50 g) were added and stirring continued at 70⁰C for a further 10 hours. Ammonium formate (50 g) was added and the reaction mixture was stirred at 70⁰C for 24 hours then cooled to room temperature. The catalyst was removed by filtration and the reaction charged with further 10% palladium on carbon (8.35 g, 7.84 mmol) and stirred at 70⁰C for 16 hours. Further ammonium formate (50 g) was added and the stirring continued for 5 hours. The reaction mixture was cooled to room temperature and a further portion of 10% palladium on carbon (8.35 g, 7.84 mmol) was added. The mixture was heated to 70⁰C for a 30 hours, cooled to room temperature and the catalyst removed by filtration and washed with EtOH. The solvent was evaporated and the residue dissolved in DCM (500 mL) and the solution washed with water (500 mL). The aqueous layer was re-extracted with DCM (500 mL), then EtOAc (500 mL x 2). The combined extracts were dried over MgSO4, filtered and evaporated to give crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 5% MeOH in DCM. Pure fractions were evaporated to dryness to afford a gum, which was slurried with ether (300 mL) and re-evaporated. Methyl tert-butyl ether (250 mL) was added and the mixture was stirred vigorously for 3 days. The solid was collected by filtration and dried to afford 6-(4-{4-[2-(4- acetylpiperazin- 1 -yl)ethoxy]phenyl}piperidin- 1 -yl)-3-(trifluoromethyl)-7,8- dihydro[l,2,4]triazolo[4,3-b]pyridazine (60.8 g, 75%) as a solid.

IH NMR (399.9 MHz, CDC13) δ 1.62 (2H, m), 1.88 (2H, m), 2.02 (3H, s), 2.49 (4H, m), 2.65 – 2.78 (5H, m), 2.94 (2H, m), 3.15 (2H, t), 3.42 (2H, m), 3.57 (2H, m), 4.03 (2H, t), 4.24 (2H, m), 6.80 (2H, d), 7.06 (2H, d); m/z = 520 [M+H]+.

The 6-[4-[4-[2-(4-acetylpiperazin-l-yl)ethoxy]phenyl]piperidin-l-yl]-3-

(trifluoromethyl)[l,2,4]triazolo[4,3-b]pyridazine used as starting material was prepared as follows :-

Preparation of 4-(piperidin-4-yl)phenol Benzyl 4-(4-hydroxyphenyl)-5,6-dihydropyridine-l(2H)-carboxylate (obtained as described in Example 4.1, preparation of starting materials) (37.7 g, 121.86 mmol) and 5% palladium on carbon (7.6 g, 3.57 mmol) in methanol (380 mL) were stirred under an atmosphere of hydrogen at 5 bar and 25°C for 2 hours. The catalyst was removed by filtration, washed with MeOH and the solvents evaporated. The crude material was triturated with diethyl ether, then the desired product collected by filtration and dried under vacuum to afford 4-(piperidin-4-yl)phenol (20.36 g, 94%) as a solid. IH NMR (399.9 MHz, DMSO-d6) δ 1.46 (2H, m), 1.65 (2H, m), 2.45 (IH, m), 2.58 (2H, m), 3.02 (2H, m), 6.68 (2H, d), 7.00 (2H, d), 9.15 (IH, s); m/z = 178 [M+H]+.

Preparation of 4- { 1- [3-(trifluor omethyl) [1 ,2,4] triazolo [4,3-b] pyridazin-6-yl] piperidin- 4-yl}phenol

DIPEA (48.2 mL, 276.86 mmol) was added to 6-chloro-3-(trifluoromethyl)- [l,2,4]triazolo[4,3-b]pyridazine (obtained as described in Monatsh. Chem. 1972, 103, 1591) (24.65 g, 110.74 mmol) and 4-(piperidin-4-yl)phenol (20.61 g, 116.28 mmol) in DMF (200 mL). The resulting solution was stirred at 80⁰C for 1 hour. The reaction mixture was cooled to room temperature, then evaporated to dryness and re-dissolved in DCM (1 L) and washed with water (2 x 1 L). The organic layer was washed with saturated brine (500 mL), then dried over MgSO4, filtered and evaporated to afford crude product. The crude product was triturated with ether to afford 4-{l-[3- (trifluoromethyl)[l,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4-yl}phenol (36.6 g, 91%) as a solid.

IH NMR (399.9 MHz, DMSO-d6) δ 1.64 (2H, m), 1.87 (2H, m), 2.75 (IH, m), 3.09 (2H, m), 4.40 (2H, m), 6.69 (2H, d), 7.05 (2H, d), 7.65 (IH, d), 8.24 (IH, d), 9.15 (IH, s); m/z = 364 [M+H]+.

Preparation of 2-(4-{l-[3-(trifluoromethyl)[l,2,4]triazolo[4,3-b]pyridazin-6- yl]piperidin-4-yl}phenoxy)ethanol

A solution of ethylene carbonate (121 g, 1376.13 mmol) in DMF (200 mL) was added dropwise to a stirred suspension of 4-{l-[3-(trifluoromethyl)[l,2,4]triazolo[4,3- b]pyridazin-6-yl]piperidin-4-yl}phenol (100 g, 275.23 mmol) and potassium carbonate (76 g, 550.45 mmol) in DMF (200 mL) at 80⁰C over a period of 15 minutes under nitrogen.

The resulting mixture was stirred at 80⁰C for 20 hours. The reaction mixture was cooled to room temperature, then concentrated and diluted with DCM (2 L), and washed sequentially with water (1 L) and saturated brine (500 mL). The organic layer was dried over MgSO4, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 70 to 100% EtOAc in isohexane. Fractions containing the desired product were evaporated to dryness then triturated with EtOAc (150 mL). The resulting solid was washed with further EtOAc (50 mL) and ether then dried to give 2-(4- { 1 -[3-(trifluoromethyl)[ 1 ,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4- yl}phenoxy)ethanol. The filtrate was evaporated and further purified by flash silica chromatography, elution gradient 70 to 100% EtOAc in isohexane. Fractions containing the desired product were evaporated to dryness then triturated with ether, dried and combined with the material previously collected to afford 2-(4- { 1 -[3-

(trifluoromethyl)[ 1 ,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4-yl}phenoxy)ethanol (89 g, 79%) as a solid.

IH NMR (399.9 MHz, DMSO-d6) δ 1.66 (2H, m), 1.88 (2H, m), 2.80 (IH, m), 3.10 (2H, m), 3.70 (2H, m), 3.95 (2H, t), 4.41 (2H, m), 4.85 (IH, t), 6.87 (2H, d), 7.18 (2H, d), 7.67 (IH, d), 8.25 (IH, d); m/z = 408 [M+H]+.

Preparation of 2-(4-{ 1- [3-(trifluoromethyl) [ 1 ,2,4] triazolo [4,3-b] pyridazin-6- yl] piperidin-4-yl}phenoxy)ethyl methanesulfonate

A solution of methanesulfonyl chloride (20.37 mL, 262.16 mmol) in DCM (300 mL) was added to 2-(4- { 1 -[3-(trifluoromethyl)[ 1 ,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4- yl}phenoxy)ethanol (89 g, 218.46 mmol) and triethylamine (60.9 mL, 436.93 mmol) in DCM (900 mL) at 0⁰C over a period of 30 minutes under nitrogen. The resulting solution was stirred at 0⁰C for 1 hour. The reaction mixture was diluted with DCM (1 L), and washed with water (2 L). The organic layer was dried over MgSO4, filtered and evaporated to afford 2-(4- { 1 -[3-(trifluoromethyl)[ 1 ,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4- yl}phenoxy)ethyl methanesulfonate (104 g, 98%) as a solid.

IH NMR (399.9 MHz, DMSO-d6) δ 1.67 (2H, m), 1.89 (2H, m), 2.83 (IH, m), 3.11 (2H, m), 3.23 (3H, s), 4.23 (2H, t), 4.41 (2H, m), 4.52 (2H, t), 6.91 (2H, d), 7.21 (2H, d), 7.66 (IH, d), 8.24 (IH, d); m/z = 486 [M+H]+. Preparation of 6-[4-[4-[2-(4-acetylpiperazin-l-yl)ethoxy]phenyl]piperidin-l-yl]-3- (trifluor omethyl) [ 1 ,2,4] triazolo [4,3-b] pyridazine DIPEA (107 mL, 613.00 mmol) was added to 2-(4-{l-[3-

(trifluoromethyl)[l,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4-yl}phenoxy)ethyl methanesulfonate (99 g, 204.33 mmol) and N-acetylpiperazine (28.8 g, 224.77 mmol) in DMA (500 mL). The resulting solution was stirred at 110⁰C for 1 hour. The reaction mixture was cooled to room temperature and the solvents were evaporated. The residue was dissolved in ethyl acetate (1 L) and the solution was washed with water (1 L). The aqueous was re-extracted with ethyl acetate (1 L) and the combined organics were washed with brine (1 L), dried over MgSO4, filtered and evaporated to give crude product. The aqueous layer was basifϊed to pH 12 with 2M NaOH, then extracted with ethyl acetate (1 L), washed with brine (IL), dried over MgSO4, filtered and evaporated to give further crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 3% MeOH in DCM then 5% MeOH in DCM. Pure fractions were evaporated to give 6-[4-[4-[2-(4-acetylpiperazin-l-yl)ethoxy]phenyl]piperidin-l-yl]-3- (trifluoromethyl)[l,2,4]triazolo[4,3-b]pyridazine (81 g, 77%) as a solid. IH NMR (399.9 MHz, DMS0-d6) δ 1.59-1.73 (2H, m), 1.87 (2H, d), 1.99 (3H, s), 2.42 (2H, t), 2.71 (2H, t), 2.76-2.86 (IH, t), 3.08 (2H, t), 3.38-3.47 (4H, m), 4.08 (2H, t), 4.41 (2H, d), 6.88 (2H, d), 7.18 (2H, d), 7.62 (IH, d), 8.26 (IH, d); m/z = 518 [M+H]+.

Example 5.5

Alternative route for the preparation of 6-(4-{4-[2-(4-acetylpiperazin-l- vDethoxyl phenyllpiperidin- l-vD-3-f trifluoromethyl)-7.,8-(iihv(iro [ 1 ,2,41 triazolo [4,3- blpyridazine Form A

Methanol (375.0 mL) was added to 6-[4-[4-[2-(4-acetylpiperazin-l- yl)ethoxy]phenyl]piperidin-l-yl]-3-(trifluoromethyl)[ 1,2,4] triazolo[4,3-b]pyridazine (25.0 g, 48 m mol) in a 2.0 L autoclave reactor and to this was added 10% Pd/C (12.5 g, 50% w/w) paste at 22-25°C under nitrogen gas atmosphere. The reaction was performed under hydrogen pressure (5.0 bar) at 50⁰C temperature for 10.0 h. The reaction mass was cooled to room temperature and the catalyst removed by filtration. Filtered cake was washed with methanol. The solvent was evaporated and the residue was azeotropically distilled by ethylacetate (2 x 125.0 mL) at 40⁰C under reduced pressure to 3.0 rel vol (75.0 mL). Drop wise addition of tert-butylmethylether (MTBE, 375.0 mL) to the reaction mass resulted in solid material, which was collected by filtration and washed with MTBE (50.0 mL). The material was dried under reduced pressure with nitrogen gas bleed at 50⁰C to afford the desired product 6-(4-{4-[2-(4-acetylpiperazin-l-yl)ethoxy]phenyl}piperidin-l-yl)-3- (trifluoromethyl)-7,8-dihydro[l,2,4]triazolo [4,3-b]pyridazine (22.3 g, 88%) as a white color free flowing solid. The isolated material was confirmed by XRPD as Form A. IH NMR (400.13 MHz, CDC13): δ 1.62 (2H, m), 1.88 (2H, m), 2.02 (3H, s), 2.49 (4H, m), 2.65 – 2.78 (5H, m), 2.94 (2H, m), 3.15 (2H, t), 3.42 (2H, m), 3.57 (2H, m), 4.03 (2H, t), 4.24 (2H, m), 6.80 (2H, d), 7.06 (2H, d); m/z = 520 [M+H]+.

The 6-[4-[4-[2-(4-acetylpiperazin-l-yl)ethoxy]phenyl]piperidin-l-yl]-3- (trifluoromethyl)[ 1,2,4] triazolo[4,3-b]pyridazine used as starting material was prepared as follows :-

Preparation of 4- { 1- [3-(trifluor omethyl) [1 ,2,4] triazolo [4,3-b] pyridazin-6-yl] piperidin- 4-yl}phenol: Dimethylacetamide (250.0 mL) was added to 6-chloro-3-(trifluoromethyl)- [l,2,4]triazolo[4,3-b]pyridazine [CAS: 40971-95-7] (50.0 g, 225 m mol) at 22-25°C in a suitable round bottom flask followed by 4-(piperidin-4-yl)phenol [CAS: 62614-84-0] (60.9 g, 236 m mol) at 22-25°C. The reaction mass was stirred to obtain a clear solution. Triethylamine (79.1 mL, 561 m mol) was slowly added to the reaction mass by drop wise addition over a period of 60 min at 25-30⁰C. Temperature was raised to 40⁰C and the reaction mass stirred for 1.0 h. After completion of reaction, water (500.0 mL) was added to the reaction mass by drop wise addition over a period of 30 min at 40-43⁰C. The slurry mass was stirred for 30 min at 40⁰C and then filtered under reduced pressure. The wet material was slurry washed using water (500.0 mL) for 30 min at 40⁰C. The solid was collected by filtration and the material washed with water (125.0 mL). The material was dried under reduced pressure with nitrogen gas bleed at 50⁰C to afford the desired product 4-{l-[3-(trifluoromethyl)[l,2,4]triazolo[4,3-b]pyridazin-6-yl]piperidin-4-yl}phenol (75.1 g, 89.9%) as a free flowing solid. IH NMR (400.13 MHz, DMSO-d6): δ 1.64 (2H, m), 1.87 (2H, m), 2.75 (IH, m), 3.09 (2H, m), 4.40 (2H, m), 6.69 (2H, d), 7.05 (2H, d), 7.65 (IH, d), 8.24 (IH, d), 9.15 (IH, s); m/z = 364 [M+H]+.

Preparation of 6-[4-[4-[2-(4-acetylpiperazin-l-yl)ethoxy]phenyl]piperidin-l-yl]-3- (trifluor omethyl) [ 1 ,2,4] triazolo [4,3-b] pyridazine:

Dichloromethane (225.0 mL) and 4-{l-[3-(trifluoromethyl)[l,2,4]triazolo[4,3-b]pyridazin- 6-yl]piperidin-4-yl} phenol (50.0 g, 138 m mol) were charged to a suitable round bottom flask at 22-25°C. Triphenylphosphine (72.2 g, 275 m mol) and l-[4-(2-hydroxy- ethyl)piperazin-l-yl]ethanone [CAS: 83502-55-0] (47.4 g, 275 m mol) were added successively to the reaction mass and stirred for 10 min at 22-25°C. Di-isopropyl azodicarboxylate (55.65 g, 275 m mol) in dichloromethane (75.0 mL) was added to the reaction mass slowly drop wise at 25-30⁰C over a period of 60-90 min. The resulting reaction mass was stirred for 1.0 h at 25-30⁰C to complete the reaction. n-Heptane (600.0 mL) was introduced to the reaction mass by drop wise addition over a period of 15-30 min at 22-25°C and stirred for 30 min at the same temperature. Thus precipitated solid was filtered and washed with n-heptane (150.0 mL). The material was then suck dried for 30 min under reduced pressure. The crude material was purified by slurry washing in methanol (325.0 mL) at 22-25°C. The solid was then collected by filtration and washed with methanol (50.0 mL). The material was dired under reduced pressure with nitrogen gas bleed at 50⁰C to afford the desired product 6-[4-[4-[2-(4-acetylpiperazin-l- yl)ethoxy]phenyl]piperidin- 1 -yl]-3-(trifluoromethyl)[ 1 ,2,4] triazolo[4,3-b]pyridazine (61.2 g, 84%) as a free flowing solid.

IH NMR (400.13 MHz, DMSO-d6): δ 1.59-1.73 (2H, m), 1.87 (2H, d), 1.99 (3H, s), 2.42 (2H, t), 2.71 (2H, t), 2.76-2.86 (IH, t), 3.08 (2H, t), 3.38-3.47 (4H, m), 4.08 (2H, t), 4.41 (2H, d), 6.88 (2H, d), 7.18 (2H, d), 7.62 (IH, d), 8.26 (IH, d); m/z = 518 [M+H]+.

Example 5.8

Preparation of 6-(4-{4-[2-(4-acetylpiperazin-l-yl)ethoxy]phenyl}piperidin-l-yl)-3-(trifluor omethyl)-7,8-dihydr 0 [1 ,2,4] triazolo [4,3-b] pyridazine maleate

A clear solution of maleic acid (0.445 g, 3.84 m mol) in methanol (1.0 mL) was added to a clear solution of 6-(4-{4-[2-(4-acetylpiperazin-l-yl)ethoxy]phenyl}piperidin-l-yl)-3- (trifluoromethyl)-7,8-dihydro[l,2,4]triazolo[4,3-b]pyridazine, obtained as described in Example 5.5, (2.0 g, 3.84 m mol) in methanol (2.0 mL) at 22-25°C and the resulting clear solution heated to 50⁰C for 30 min. The reaction mass was cooled to 22-25°C and ethylacetate (16.0 mL) added drop wise to the reaction mass at 22-25°C. The reaction mass was then stirred for 60 min at 22-25°C. The resulting white color material was collected by filtration and washed with ethylacetate (5.0 mL). The material was dried under reduced pressure with nitrogen gas bleed at 50⁰C to afford the desired product 6-(4- {4-[2-(4-acetylpiperazin-l-yl)ethoxy]phenyl}piperidin-l-yl)-3-(trifluoromethyl)-7,8- dihydro[l,2,4]triazolo[4,3-b]pyridazine maleate (2.21 g, 90.0%) as free flowing white color material.

IH NMR (400.13 MHz, DMSO-d₆): δ 1.62 (2H, m), 1.77 (2H, m), 2.02 (3H, s), 2.75 (IH, m), 2.77 (2H, m), 2.80 (2H, m), 2.95 (4H, m), 3.16 (2H, t), 3.36 (6H, m), 4.22 (4H, m), 6.08 (2H, s), 6.91 (2H, d), 7.17 (2H, d).

PAPER

Bioorg Med Chem Lett. 2013 Apr 1;23(7):1945-8

Bioorganic & Medicinal Chemistry Letters

Volume 23, Issue 7, 1 April 2013, Pages 1945–1948

Removal of the basic piperazine nitrogen atom, introduction of a solubilising end group and partial reduction of the triazolopyridazine moiety in the previously-described lead androgen receptor downregulator 6-[4-(4-cyanobenzyl)piperazin-1-yl]-3-(trifluoromethyl)[1,2,4]triazolo[4,3-b]pyridazine (1) addressed hERG and physical property issues, and led to clinical candidate 6-(4-{4-[2-(4-acetylpiperazin-1-yl)ethoxy]phenyl}piperidin-1-yl)-3-(trifluoromethyl)-7,8-dihydro[1,2,4]triazolo[4,3-b]pyridazine (12), designated AZD3514, that is being evaluated in a Phase I clinical trial in patients with castrate-resistant prostate cancer.

http://www.sciencedirect.com/science/article/pii/S0960894X13002321

SYNTHESIS

AZD 3514

6-(4-{4-[2-(4-Acetylpiperazin-1-yl)ethoxy]phenyl}piperidin-1-yl)-3-(trifluoromethyl)-7,8-dihydro[1,2,4]triazolo[4,3-b]pyridazine AZD 3514

SYNTHETIC ROUTE 2ND GENERATION

SYNTHETIC ROUTE 4TH GENERATION

REFERENCES

1: Bradbury RH, Acton DG, Broadbent NL, Brooks AN, Carr GR, Hatter G, Hayter BR,  Hill KJ, Howe NJ, Jones RD, Jude D, Lamont SG, Loddick SA, McFarland HL, Parveen  Z, Rabow AA, Sharma-Singh G, Stratton NC, Thomason AG, Trueman D, Walker GE, Wells SL, Wilson J, Wood JM. Discovery of AZD3514, a small-molecule androgen receptor downregulator for treatment of advanced prostate cancer. Bioorg Med Chem Lett. 2013 Apr 1;23(7):1945-8. doi: 10.1016/j.bmcl.2013.02.056. Epub 2013 Feb 21. PubMed PMID: 23466225.

///////////////AZD 3514 MALEATE, AZD 3514 , AZD-3514, Prostate cancer, Androgen receptor downregulator, AZD3514, 1240299-33-5

1H-Indole-1-acetic acid, 4-(acetylamino)-3-[(4-chlorophenyl)thio]-2-methyl-

• 2-[4-acetamido-3-(4-chlorophenyl)sulfanyl-2-methylindol-1-yl]acetic acid
• Originator AstraZeneca
• Developer AstraZeneca; Johns Hopkins University
• Class Antiasthmatics
• Mechanism of Action Prostaglandin D2 receptor antagonists
• • Phase II Urticaria
  • Discontinued Asthma; Chronic obstructive pulmonary disease

  Most Recent Events

  • 09 Mar 2016 AZD 1981 is still in phase II trials for Urticaria in USA (PO)
  • 07 Mar 2016 Johns Hopkins University in collaboration with AstraZeneca completes a phase II trial in Urticaria in USA (PO) (NCT02031679)
  • 04 Mar 2016 Efficacy and safety data from a phase II trial in Urticaria presented at the Annual Meeting of the American Academy of Allergy, Asthma and Immunology (AAAAI-2016)

https://ncats.nih.gov/files/AZD1981.pdf

SEE

NMR

HPLC

AZD1981 is a potent, selective CRTh2 (DP2) receptor antagonist with IC50 of 4 nM, showing >1000-fold selectivity over more than 340 other enzymes and receptors, including DP1. Phase 2.

118 patients were randomised to treatment (AZD1981 n = 61; placebo n = 57); 83% of patients were male and the mean age was 63 years (range 43-83). There were no significant differences in the mean difference in change from baseline to end of treatment between AZD1981 and placebo for the co-primary endpoints of pre-bronchodilator FEV1 (AZD1981-placebo: -0.015, 95% CI: -0.10 to 0.070; p = 0.72) and CCQ total score (difference: 0.042, 95% CI: -0.21 to 0.30; p = 0.75). Similarly, no differences were observed between treatments for the other outcomes of lung function, COPD symptom score, 6-MWT, BODE index, and use of reliever medication. AZD1981 was well tolerated.

CONCLUSION:

There was no beneficial clinical effect of AZD1981, at a dose of 1000 mg twice daily for 4 weeks, in patients with moderate to severe COPD. AZD1981 was well tolerated and no safety concerns were identified.

Biological Activity

Protocol(Only for Reference)

Kinase Assay: ^[2]

Animal Study: ^[1]

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

References

[1] Luker T, et al. Bioorg Med Chem Lett. 2011, 21(21), 6288-6292.

[2] Schmidt JA, et al. Br J Pharmacol. 2013, 168(7), 1626-1638.

Clinical Trial Information( data from http://clinicaltrials.gov, updated on 2016-07-09)

///////////

CC1=C(C2=C(N1CC(=O)O)C=CC=C2NC(=O)C)SC3=CC=C(C=C3)Cl

Belinostat (PXD101)

 FAST TRACK FDA , ORPHAN STATUS

Approved by FDA……http://www.drugs.com/newdrugs/fda-approves-beleodaq-belinostat-peripheral-t-cell-lymphoma-4052.html?utm_source=ddc&utm_medium=email&utm_campaign=Today%27s+news+summary+-+July+3%2C+2014

July 3, 2014 — The U.S. Food and Drug Administration today approved Beleodaq (belinostat) for the treatment of patients with peripheral T-cell lymphoma (PTCL), a rare and fast-growing type of non-Hodgkin lymphoma (NHL). The action was taken under the agency’s accelerated approval program.

Belinostat (PXD101) is a novel HDAC inhibitor with IC50 of 27 nM, with activity demonstrated in cisplatin-resistant tumors.

CLINICAL TRIALS…http://clinicaltrials.gov/search/intervention=Belinostat+OR+PXD101

MP 172–174 °C, (lit.(@) 172 °C). ¹H NMR (400 MHz, DMSO-d₆) δ = 10.75–10.42 (m, 2H), 9.15 (s, 1H), 7.92 (s, 1H), 7.78 (d, J = 7.8 Hz, 1H), 7.71 (d, J = 7.8 Hz, 1H), 7.56 (d, J = 7.8 Hz, 1H),7.47 (d, J = 15.8 Hz, 1H), 7.24 (m, 2H), 7.10–7.01 (m, 3H), 6.51 (d, J = 15.8 Hz, 1H). MS (ESI): m/z = 318.6 [M+H] ⁺.

@ Finn, P. W.; Bandara, M.; Butcher, C.; Finn, A.; Hollinshead, R.; Khan, N.; Law, N.; Murthy, S.; Romero,R.; Watkins, C.; Andrianov, V.; Bokaldere, R. M.; Dikovska, K.; Gailite, V.; Loza, E.; Piskunova, I.;Starchenkov, I.; Vorona, M.; Kalvinsh, I. Helv. Chim. Acta 2005, 88, 1630, DOI: 10.1002/hlca.200590129

Beleodaq and Folotyn are marketed by Spectrum Pharmaceuticals, Inc., based in Henderson, Nevada. Istodax is marketed by Celgene Corporation based in Summit, New Jersey.

Belinostat was granted orphan drug status for the treatment of Peripheral T-cell lymphoma (PTCL) in the US in September 2009 and the EU in October 2012. In July 2015, an orphan drug designation has also been granted for malignant thymoma in the EU.

Belinostat received its first global approval in the US-FDA on 3 July 2014 for the intravenous (IV) treatment of relapsed or refractory PTCL in adults.

414864-00-9  cas no

866323-14-0

(2E)-N-hydroxy-3-[3-(phenylsulfamoyl)phenyl]acrylamide

A novel HDAC inhibitor

PTCL comprises a diverse group of rare diseases in which lymph nodes become cancerous. In 2014, the National Cancer Institute estimates that 70,800 Americans will be diagnosed with NHL and 18,990 will die. PTCL represents about 10 to 15 percent of NHLs in North America.Belinostat inhibits the growth of tumor cells (A2780, HCT116, HT29, WIL, CALU-3, MCF7, PC3 and HS852) with IC50 from 0.2-0.66 μM. PD101 shows low activity in A2780/cp70 and 2780AD cells. Belinostat inhibits bladder cancer cell growth, especially in 5637 cells, which shows accumulation of G0-G1 phase, decrease in S phase, and increase in G2-M phase. Belinostat also shows enhanced tubulin acetylation in ovarian cancer cell lines. A recent study shows that Belinostat activates protein kinase A in a TGF-β signaling-dependent mechanism and decreases survivin mRNA.

Beleodaq works by stopping enzymes that contribute to T-cells, a type of immune cell, becoming cancerous. It is intended for patients whose disease returned after treatment (relapsed) or did not respond to previous treatment (refractory).

“This is the third drug that has been approved since 2009 for the treatment of peripheral T-cell lymphoma,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “Today’s approval expands the number of treatment options available to patients with serious and life-threatening diseases.”

The FDA granted accelerated approval to Folotyn (pralatrexate) in 2009 for use in patients with relapsed or refractory PTCL and Istodax (romidepsin) in 2011 for the treatment of PTCL in patients who received at least one prior therapy.

The safety and effectiveness of Beleodaq was evaluated in a clinical study involving 129 participants with relapsed or refractory PTCL. All participants were treated with Beleodaq until their disease progressed or side effects became unacceptable. Results showed 25.8 percent of participants had their cancer disappear (complete response) or shrink (partial response) after treatment.

The most common side effects seen in Beleodaq-treated participants were nausea, fatigue, fever (pyrexia), low red blood cells (anemia), and vomiting.

The FDA’s accelerated approval program allows for approval of a drug based on surrogate or intermediate endpoints reasonably likely to predict clinical benefit for patients with serious conditions with unmet medical needs. Drugs receiving accelerated approval are subject to confirmatory trials verifying clinical benefit. Beleodaq also received orphan product designation by the FDA because it is intended to treat a rare disease or condition.

BELINOSTAT

Belinostat (trade name Beleodaq, previously known as PXD101) is a histone deacetylase inhibitor drug developed by TopoTargetfor the treatment of hematological malignancies and solid tumors.^[2]

It was approved in July 2014 by the US FDA to treat peripheral T-cell lymphoma.^[3]

In 2007 preliminary results were released from the Phase II clinical trial of intravenous belinostat in combination with carboplatin andpaclitaxel for relapsed ovarian cancer.^[4] Final results in late 2009 of a phase II trial for T-cell lymphoma were encouraging.^[5]Belinostat has been granted orphan drug and fast track designation by the FDA,^[6] and was approved in the US for the use againstperipheral T-cell lymphoma on 3 July 2014.^[3] It is not approved in Europe as of August 2014.^[7]

The approved pharmaceutical formulation is given intravenously.^[8]:180 Belinostat is primarily metabolized by UGT1A1; the initial dose should be reduced if the recipient is known to be homozygous for the UGT1A1*28 allele.^{[8]:179 and 181}

NCI: A novel hydroxamic acid-type histone deacetylase (HDAC) inhibitor with antineoplastic activity. Belinostat targets HDAC enzymes, thereby inhibiting tumor cell proliferation, inducing apoptosis, promoting cellular differentiation, and inhibiting angiogenesis. This agent may sensitize drug-resistant tumor cells to other antineoplastic agents, possibly through a mechanism involving the down-regulation of thymidylate synthase

The study of inhibitors of histone deacetylases indicates that these enzymes play an important role in cell proliferation and differentiation. The inhibitor Trichostatin A (TSA) (Yoshida et al., 1990a) causes cell cycle arrest at both G1 and G2 phases (Yoshida and Beppu, 1988), reverts the transformed phenotype of different cell lines, and induces differentiation of Friend leukaemia cells and others (Yoshida et al., 1990b). TSA (and SAHA) have been reported to inhibit cell growth, induce terminal differentiation, and prevent the formation of tumours in mice (Finnin et al., 1999).

Trichostatin A (TSA)

Suberoylanilide Hydroxamic Acid (SAHA)

Cell cycle arrest by TSA correlates with an increased expression of gelsolin (Hoshikawa et al., 1994), an actin regulatory protein that is down regulated in malignant breast cancer (Mielnicki et al., 1999). Similar effects on cell cycle and differentiation have been observed with a number of deacetylase inhibitors (Kim et al., 1999). Trichostatin A has also been reported to be useful in the treatment of fibrosis, e.g., liver fibrosis and liver cirrhosis. See, e.g., Geerts et al., 1998.

Recently, certain compounds that induce differentiation have been reported to inhibit histone deacetylases. Several experimental antitumour compounds, such as trichostatin A (TSA), trapoxin, suberoylanilide hydroxamic acid (SAHA), and phenylbutyrate have been reported to act, at least in part, by inhibiting histone deacetylase (see, e.g., Yoshida et al., 1990; Richon et al., 1998; Kijima et al., 1993). Additionally, diallyl sulfide and related molecules (see, e.g., Lea et al., 1999), oxamflatin (see, e.g., Kim et al., 1999), MS-27-275, a synthetic benzamide derivative (see, e.g., Saito et al., 1999; Suzuki et al., 1999; note that MS-27-275 was later re-named as MS-275), butyrate derivatives (see, e.g., Lea and Tulsyan, 1995), FR901228 (see, e.g., Nokajima et al., 1998), depudecin (see, e.g., Kwon et al., 1998), and m-carboxycinnamic acid bishydroxamide (see, e.g., Richon et al., 1998) have been reported to inhibit histone deacetylases. In vitro, some of these compounds are reported to inhibit the growth of fibroblast cells by causing cell cycle arrest in the G1 and G2 phases, and can lead to the terminal differentiation and loss of transforming potential of a variety of transformed cell lines (see, e.g., Richon et al, 1996; Kim et al., 1999; Yoshida et al., 1995; Yoshida & Beppu, 1988). In vivo, phenybutyrate is reported to be effective in the treatment of acute promyelocytic leukemia in conjunction with retinoic acid (see, e.g., Warrell et al., 1998). SAHA is reported to be effective in preventing the formation of mammary tumours in rats, and lung tumours in mice (see, e.g., Desai et al., 1999).

The clear involvement of HDACs in the control of cell proliferation and differentiation suggest that aberrant HDAC activity may play a role in cancer. The most direct demonstration that deacetylases contribute to cancer development comes from the analysis of different acute promyelocytic leukaemias (APL). In most APL patients, a translocation of chromosomes 15 and 17 (t(15;17)) results in the expression of a fusion protein containing the N-terminal portion of PML gene product linked to most of RARσ (retinoic acid receptor). In some cases, a different translocation (t(11 ;17)) causes the fusion between the zinc finger protein PLZF and RARα. In the absence of ligand, the wild type RARα represses target genes by tethering HDAC repressor complexes to the promoter DNA. During normal hematopoiesis, retinoic acid (RA) binds RARα and displaces the repressor complex, allowing expression of genes implicated in myeloid differentiation. The RARα fusion proteins occurring in APL patients are no longer responsive to physiological levels of RA and they interfere with the expression of the RA- inducible genes that promote myeloid differentiation. This results in a clonal expansion of promyelocytic cells and development of leukaemia. In vitro experiments have shown that TSA is capable of restoring RA-responsiveness to the fusion RARα proteins and of allowing myeloid differentiation. These results establish a link between HDACs and oncogenesis and suggest that HDACs are potential targets for pharmaceutical intervention in APL patients. (See, for example, Kitamura et al., 2000; David et al., 1998; Lin et al., 1998).

BELINOSTAT

Furthermore, different lines of evidence suggest that HDACs may be important therapeutic targets in other types of cancer. Cell lines derived from many different cancers (prostate, coloreetal, breast, neuronal, hepatic) are induced to differentiate by HDAC inhibitors (Yoshida and Horinouchi, 1999). A number of HDAC inhibitors have been studied in animal models of cancer. They reduce tumour growth and prolong the lifespan of mice bearing different types of transplanted tumours, including melanoma, leukaemia, colon, lung and gastric carcinomas, etc. (Ueda et al., 1994; Kim et al., 1999).

Psoriasis is a common chronic disfiguring skin disease which is characterised by well-demarcated, red, hardened scaly plaques: these may be limited or widespread. The prevalence rate of psoriasis is approximately 2%, i.e., 12.5 million sufferers in the triad countries (US/Europe/Japan). While the disease is rarely fatal, it clearly has serious detrimental effects upon the quality of life of the patient: this is further compounded by the lack of effective therapies. Present treatments are either ineffective, cosmetically unacceptable, or possess undesired side effects. There is therefore a large unmet clinical need for effective and safe drugs for this condition. Psoriasis is a disease of complex etiology. Whilst there is clearly a genetic component, with a number of gene loci being involved, there are also undefined environmental triggers. Whatever the ultimate cause of psoriasis, at the cellular level, it is characterised by local T-cell mediated inflammation, by keratinocyte hyperproliferation, and by localised angiogenesis. These are all processes in which histone deacetylases have been implicated (see, e.g., Saunders et al., 1999; Bernhard et al, 1999; Takahashi et al, 1996; Kim et al , 2001 ). Therefore HDAC inhibitors may be of use in therapy for psoriasis. Candidate drugs may be screened, for example, using proliferation assays with T-cells and/or keratinocytes.

 CLIP

PXD101/Belinostat®

(E)-N-hydroxy-3-(3-phenylsulfamoyl-phenyl)-acrylamide, also known as PXD101 and Belinostat®, shown below, is a well known histone deacetylate (HDAC) inhibitor. It is being developed for treatment of a range of disorders mediated by HDAC, including proliferative conditions (such as cancer and psoriasis), malaria, etc.

PXD101 was first described in WO 02/30879 A2. That document describes a multi-step method of synthesis which may conveniently be illustrated by the following scheme.

PATENT

GENERAL SYNTHESIS

WO2002030879A2

IGNORE 10

ENTRY 45 IS BELINOSTAT

Scheme 1

By using amines instead of aniline, the corresponding products may be obtained. The use of aniline, 4-methoxyaniline, 4-methylaniline, 4-bromoaniline, 4-chloroaniline, 4-benzylamine, and 4-phenethyamine, among others, is described in the Examples below.

In another method, a suitable amino acid (e.g., ω-amino acid) having a protected carboxylic acid (e.g., as an ester) and an unprotected amino group is reacted with a sulfonyl chloride compound (e.g., RSO₂CI) to give the corresponding sulfonamide having a protected carboxylic acid. The protected carboxylic acid is then deprotected using base to give the free carboxylic acid, which is then reacted with, for example, hydroxylamine 2-chlorotrityl resin followed by acid (e.g., trifluoroacetic acid), to give the desired carbamic acid.

One example of this approach is illustrated below, in Scheme 2, wherein the reaction conditions are as follows: (i) RSO₂CI, pyridine, DCM, room temperature, 12 hours; (ii) 1 M LiOH or 1 M NaOH, dioxane, room temperature, 3-48 hours; (iii) hydroxylamine 2-chlorotrityl resin, HOAt, HATU, DIPEA, DCM, room temperature, 16 hours; and (iv) TFA/DCM (5:95, v/v), room temperature, 1.5 hours.

Scheme 2

Additional methods for the synthesis of compounds of the present invention are illustrated below and are exemplified in the examples below.

Scheme 3A

Scheme 3B

Scheme 4

Scheme 8

Scheme 9

PATENT

SYNTHESIS

WO2002030879A2

Example 1

3-Formylbenzenesulfonic acid, sodium salt (1)

Oleum (5 ml) was placed in a reaction vessel and benzaldehyde (2.00 g, 18.84 mmol) was slowly added not exceeding the temperature of the reaction mixture more than 30°C. The obtained solution was stirred at 40°C for ten hours and at ambient temperature overnight. The reaction mixture was poured into ice and extracted with ethyl acetate. The aqueous phase was treated with CaC0₃ until the evolution of C0₂ ceased (pH~6-7), then the precipitated CaSO₄was filtered off and washed with water. The filtrate was treated with Na₂CO₃ until the pH of the reaction medium increased to pH 8, obtained CaCO3 was filtered off and water solution was evaporated in vacuum. The residue was washed with methanol, the washings were evaporated and the residue was dried in desiccator over P₂Oβ affording the title compound (2.00 g, 51%). ¹H NMR (D₂0), δ: 7.56-8.40 (4H, m); 10.04 ppm (1 H, s).

Example 2 3-(3-Sulfophenyl)acrylic acid methyl ester, sodium salt (2)

Sodium salt of 3-formylbenzenesulfonic acid (1) (1.00 g, 4.80 mmol), potassium carbonate (1.32 g, 9.56 mmol), trimethyl phosphonoacetate (1.05 g, 5.77 mmol) and water (2 ml) were stirred at ambient temperature for 30 min., precipitated solid was filtered and washed with methanol. The filtrate was evaporated and the title compound (2) was obtained as a white solid (0.70 g, 55%). ¹H NMR (DMSO- d_βl HMDSO), δ: 3.68 (3H, s); 6.51 (1 H, d, J=16.0 Hz); 7.30-7.88 (5H, m).

Example 3 3-(3-Chlorosulfonylphenyl)acrylic acid methyl ester (3)

To the sodium salt of 3-(3-sulfophenyl)acrylic acid methyl ester (2) (0.670 g, 2.53 mmol) benzene (2 ml), thionyl chloride (1.508 g, 0.9 ml, 12.67 mmol) and 3 drops of dimethylformamide were added and the resultant suspension was stirred at reflux for one hour. The reaction mixture was evaporated, the residue was dissolved in benzene (3 ml), filtered and the filtrate was evaporated to give the title compound (0.6’40 g, 97%).

Example 4 3-(3-Phenylsulfamoylphenyl)acrylic acid methyl ester (4a)

A solution of 3-(3-chlorosulfonylphenyl)acrylic acid methyl ester (3) (0.640 g, 2.45 mmol) in dichloromethane (2 ml) was added to a mixture of aniline (0.465 g, 4.99 mmol) and pyridine (1 ml), and the resultant solution was stirred at 50°C for one hour. The reaction mixture was evaporated and the residue was partitioned between ethyl acetate and 10% HCI. The organic layer was washed successively with water, saturated NaCl, and dried (Na₂S0 ). The solvent was removed and the residue was chromatographed on silica gel with chloroform-ethyl acetate (7:1 , v/v) as eluent. The obtained product was washed with diethyl ether to give the title compound (0.226 g, 29%). ¹H NMR (CDCI₃, HMDSO), δ: 3.72 (3H, s); 6.34 (1H, d, J=16.0 Hz); 6.68 (1 H, br s); 6.92-7.89 (10H, m).

Example 5 3-(3-Phenylsulfamoylphenyl)acrylic acid (5a)

3-(3-Phenylsulfamoylphenyl)acrylic acid methyl ester (4a) (0.220 g, 0.69 mmol) was dissolved in methanol (3 ml), 1N NaOH (2.08 ml, 2.08 mmol) was added and the resultant solution was stirred at ambient temperature overnight. The reaction mixture was partitioned between ethyl acetate and water. The aqueous layer was acidified with 10% HCI and stirred for 30 min. The precipitated solid was filtered, washed with water and dried in desiccator over P₂Os to give the title compound as a white solid (0.173 g, 82%). Example 6 3-(3-Phenylsulfamoylphenyl)acryloyl chloride (6a)

To a suspension of 3-(3-phenylsulfamoylphenyl)acrylic acid (5a) (0.173 g, 0.57 mmol) in dichloromethane (2.3 ml) oxalyl chloride (0.17 ml, 1.95 mmol) and one drop of dimethylformamide were added. The reaction mixture was stirred at 40°C for one hour and concentrated under reduced pressure to give crude title compound (0.185 g).

Example 7

N-Hydroxy-3-(3-phenylsulfamoylphenyl)acrylamide (7a) (PX105684) BELINOSTAT

To a suspension of hydroxylamine hydrochloride (0.200 g, 2.87 mmol) in tetrahydrofuran (3.5 ml) a saturated NaHCOβ solution (2.5 ml) was added and the resultant mixture was stirred at ambient temperature for 10 min. To the reaction mixture a 3-(3-phenylsulfamoylphenyl)acryloyl chloride (6a) (0.185 g) solution in tetrahydrofuran (2.3 ml) was added and stirred at ambient temperature for one hour. The reaction mixture was partitioned between ethyl acetate and 2N HCI. The organic layer was washed successively with water and saturated NaCl, the solvent was removed and the residue was washed with acetonitrile and diethyl ether.

The title compound was obtained as a white solid (0.066 g, 36%), m.p. 172°C. BELINOSTAT

¹H NMR (DMSO-d6, HMDSO), δ: 6.49 (1 H, d, J=16.0 Hz); 7.18-8.05 (10H, m); 9.16 (1 H, br s); 10.34 (1 H, s); 10.85 ppm (1 H, br s).

HPLC analysis on Symmetry C₁₈column: impurities 4% (column size 3.9×150 mm; mobile phase acetonitrile – 0.1 M phosphate buffer (pH 2.5), 40:60; sample concentration 1 mg/ml; flow rate 0.8 ml/ min; detector UV 220 nm).

Anal. Calcd for C₁₅Hι₄N₂0₄S, %: C 56.59, H 4.43, N 8.80. Found, %: C 56.28, H 4.44, N 8.56.

PATENT

https://www.google.com/patents/CN102786448A?cl=en

Example: belinostat (compound of formula I) Preparation of

Methods of operation:

The compound of formula II (4. Og) added to the reactor, was added methanol 30ml, and stirred to dissolve, was added IM aqueous sodium hydroxide solution (38mL), stirred at room temperature overnight, the reaction was completed, ethyl acetate was added (IOmL) ^ K (20mL), stirred for 5 minutes, phase separation, the ethyl acetate phase was discarded, the aqueous phase was acidified with 10% hydrochloric acid to pH2, stirred at room temperature for 30 minutes, filtered, washed with water, and dried to give hydrolyzate 3. lg, yield rate of 81.6%.

 The hydrolyzate (3. Og) added to the reactor, was added methylene chloride (53. 2g), dissolved with stirring, was added oxalyl chloride (2.8mL, 0.0032mol) at room temperature was added I drop DMF, reflux I hours, concentrated and the residue was dissolved in THF (30mL) alternate, the other to take a reaction flask was added hydroxylamine hydrochloride (3. 5g, 0.05mol), THF (50mL), saturated aqueous sodium bicarbonate (40mL), the mixture at room temperature under stirring for 10 minutes, then was added to spare, stirred at room temperature for I hour, the reaction was complete, at – at room temperature was added ethyl acetate (50mL), 2M hydrochloric acid (50mL), stirred for 5 minutes the phases were separated, the aqueous phase was discarded, the organic layer was washed with water, saturated brine, dried, filtered and concentrated to give crude product belinostat, recrystallized from ethyl acetate, 50 ° C and dried for 8 hours to give white crystals 2. 6g, yield 83.8%. .  1H-NMR (DMS0-d6, 400MHz) δ: 6 50 (1H, d, J = 16. OHz); 7 07 (d, J = 7. 8Hz, 2H); 7 16 (t.. , J = 7. 3Hz, 1H);. 7 25 (m, 2H);. 7 45 (t, J = 7. 8Hz, 1H);. 7 60 (d, J = 15. 9Hz, 1H); 7 . 62 (d, J = 7. 7Hz, 1H);. 7 75 (d, J = 7. 8Hz, 1H);. 7 88 (br s. ‘1H);. 9 17 (br s’ 1H); 10. 35 (s, 1H);. 10 82ppm (br s, 1H). ·

Step a): Preparation of Compound III

 The carboxy benzene sulfonate (224g, Imol), anhydrous methanol (2300g), concentrated hydrochloric acid (188. 6g) refluxing

3-5 hours, filtered and the filtrate was added anhydrous sodium bicarbonate powder (200g), stirred for I hour, filtered, the filter residue was discarded, the filtrate was concentrated. The concentrate was added methanol (2000g), stirred at room temperature for 30 minutes, filtered and the filtrate was concentrated to dryness, 80 ° C and dried for 4 hours to give a white solid compound III147g, yield 61.8%.

Step b): Preparation of Compound IV

 Compound III (50g, 0. 21mol), phosphorus oxychloride (250mL) was refluxed for 2_6 hours, completion of the reaction, cooled to

0-5 ° C, was slowly added to ice water, stirred for 2 hours and filtered to give a brown solid compound IV40 g, due to the instability of Compound IV, directly into the next reaction without drying.

Preparation of Compound V: [0040] Step c)

The aniline (5. 58g, 0. 06mol) and 30mL of toluene added to the reactor, stirred to dissolve, in step b) the resulting compound IV (7. 05g, O. 03mol) was dissolved in 60 ml of toluene, at room temperature dropwise added to the reactor, the addition was completed, stirring at room temperature for 1-2 hours, the reaction was completed, the filtered solid washed with water, and then recrystallized from toluene, 50 ° C and dried for 4 hours to obtain a white crystalline compound V6. Og, yield 73%. mp:.. 144 4-145 2. . .

 1H- bandit R (CDCl3, 400MHz) δ:…. 3 92 (s, 3H); 6 80 (. Br s, 1H); 7 06-7 09 (m, 2H); 7 11. . -7 15 (m, 1H);.. 7 22-7 26 (m, 2H);. 7 51 (t, J = 7. 8Hz, 1H);.. 7 90-7 93 (dt, J = . 1.2,7 8Hz, 1H); 8 18-8 21 (dt, J = I. 4, 7. 8Hz, 1H);… 8 48 (t, J = L 6Hz, 1H).

 IR v ™ r: 3243,3198,3081,2953,1705,1438,1345,766,702,681cm-1.

 Step d): Preparation of Compound VI

 The anhydrous lithium chloride 2. 32g, potassium borohydride 2. 96g, THF50mL added to the reactor, stirring evenly, Compound V (8g, 0. 027mol) was dissolved in 7mL of tetrahydrofuran, was slowly dropped into the reactor was heated under reflux for 5 hours, the reaction was completed, the force mouth 40mL water and ethyl acetate 40mL, stirred for half an hour, allowed to stand for separation, the organic layer was washed with 40mL water, concentrated under reduced pressure to give the crude product, the crude product was recrystallized from toluene, solid 50 V dried for 4 hours to give a white crystalline compound VI6. 82g, yield 90. O%. mp:.. 98 2-98 6. . .

1H-NMR (DMS0-d6, 400ΜΗζ) δ:….. 4 53 (s, 2H); 5 39 (s, 1H); 6 99-7 03 (m, 1H); 7 08- 7. ll (m, 2H);.. 7 19-7 24 (m, 2H);.. 7 45-7 52 (m, 2H);.. 7 61-7 63 (dt, J = I. 8 , 7 4Hz, 1H);.. 7 79 (br s, 1H);. 10. 26 (s, 1H).

IRv =: 3453,3130,2964,1488,1151,1031, 757,688cm_10

Step e): Preparation of Compound VII

After Compound VI (7.5g, 0.028mol) dissolved in acetone was added 7ml, dichloromethane was added 60mL, supported on silica gel was added PCC at room temperature 20g, stirred at room temperature for 12-24 hours, the reaction was complete, filtered and the filtrate was purified The layers were separated and the aqueous layer was discarded after the organic phase is washed 30mL5% aqueous sodium bicarbonate, evaporated to dryness under reduced pressure to give the crude product, the crude product was recrystallized from toluene, 50 ° C and dried for 8 hours to give white crystalline compound VII4. 7g, yield 62.7%. mp:.. 128 1-128 5 ° C.

 1H- bandit R (CDCl3,400MHz) δ:…. 7 08-7 15 (m, 4Η); 7 · 23-7 27 (m, 2H); 7 · 60-7 64 (t, J = 7 7Hz, 1Η);.. 8 00 (d, J = 7. 6Hz, 1Η);. 8 04 (d, J = 7. 6Hz, 1Η);. 8 30 (br s’ 1Η).; 10. 00 (S, 1Η).

 IR ν ™ Γ: 3213,3059,2964,2829,1687,1480,1348,1159,1082,758,679cm_10

Preparation of compounds of formula II: [0055] Step f)

 phosphoryl trimethylorthoacetate (2. 93g, 0. 0161mol) added to the reaction vessel, THF30mL, stirring to dissolve, cooled to -5-0 ° C, was added sodium hydride (O. 8g, content 80%) , the addition was completed, stirring for 10-20 minutes, was added dropwise the compound VII (4g, O. 0156mol) and THF (20mL) solution, stirred for 1_4 hours at room temperature, the reaction was complete, 10% aqueous ammonium chloride solution was added dropwise 50mL, and then After addition of 50mL of ethyl acetate, stirred 30min rested stratification, the aqueous layer was discarded, the organic phase was concentrated under reduced pressure to give the crude product, the crude product was recrystallized from methanol 60mL, 50 ° C and dried for 8 hours to give white crystalline compound 113. 6g, yield 75%. mp:.. 152 0-152 5 ° C.

 1H-Nmr (Cdci3JOOmHz) δ:…. 3 81 (s, 3H); 6 40 (d, J = 16. 0Hz, 1H); 6 79 (. Br s, 1H); 7 08 ( d, J = 7. 8Hz, 2H);. 7 14 (t, J = 7. 3Hz, 1H);. 7 24 (m, 2H);. 7 46 (t, J = 7. 8Hz, 1H); 7. 61 (d, J = 16. ΟΗζ, ΙΗ);. 7 64 (d, J = 7. 6Hz, 1H);. 7 75 (d, J = 7. 8Hz, 1H);. 7 89 (br . s, 1H).

IR v ^ :: 3172,3081,2954,2849,1698,1475,1345,1157,773,714,677cm-1.

PATENT

SYNTHESIS

US20100286279

CLIP

SYNTHESIS AND SPECTRAL DATA

Journal of Medicinal Chemistry, 2011 ,  vol. 54,  13  pg. 4694 – 4720

(E)-N-Hydroxy-3-(3-phenylsulfamoyl-phenyl)-acrylamide (28, belinostat, PXD101).

http://pubs.acs.org/doi/full/10.1021/jm2003552

 http://pubs.acs.org/doi/suppl/10.1021/jm2003552/suppl_file/jm2003552_si_001.pdf

The methyl ester (27) (8.0 g) was prepared according to reported synthetic route,

(Watkins, C. J.; Romero-Martin, M.-R.; Moore, K. G.; Ritchie, J.; Finn, P. W.; Kalvinsh, I.;
Loza, E.; Dikvoska, K.; Gailite, V.; Vorona, M.; Piskunova, I.; Starchenkov, I.; Harris, C. J.;
Duffy, J. E. S. Carbamic acid compounds comprising a sulfonamide linkage as HDAC
inhibitors. PCT Int. Appl. WO200230879A2, April 18, 2002.)
but using procedure D (Experimental Section) or method described for 26 to convert the methyl ester to crude
hydroxamic acid which was further purified by chromatography (silica, MeOH/DCM = 1:10) to
afford 28 (PXD101) as off-white or pale yellow powder (2.5 g, 31%).

LC–MS m/z 319.0 ([M +H]+).

1H NMR (DMSO-d6)  12–9 (very broad, 2H), 7.90 (s, 1H), 7.76 (d, J = 7.7 Hz, 1H), 7.70 (d, J

= 7.8 Hz, 1H), 7.56 (t, J = 7.8 Hz, 1H), 7.44 (d, J = 15.8 Hz, 1H), 7.22 (t, J = 7.8 Hz, 2H), 7.08 (d,J = 7.8 Hz, 2H), 7.01 (t, J = 7.3 Hz, 1H), 6.50 (d, J = 15.8 Hz, 1H);

13C NMR (DMSO-d6)  162.1, 140.6, 138.0, 136.5, 135.9, 131.8, 130.0, 129.2, 127.1, 124.8, 124.1, 121.3, 120.4.

Anal.
(C15H14N2O4S) C, H, N

PATENT

SYNTHESIS

WO2009040517A2

PXDIOI / Belinostat®

(E)-N-hydroxy-3-(3-phenylsulfamoyl-phenyl)-acrylamide, also known as PXD101 and Belinostat®, shown below, is a well known histone deacetylate (HDAC) inhibitor. It is being developed for treatment of a range of disorders mediated by HDAC, including proliferative conditions (such as cancer and psoriasis), malaria, etc.

PXD101 was first described in WO 02/30879 A2. That document describes a multi-step method of synthesis which may conveniently be illustrated by the following scheme.

Scheme 1

Not isolated

ed on (A)

on (D)

d on (H)

There is a need for alternative methods for the synthesis of PXD101 and related compounds for example, methods which are simpler and/or employ fewer steps and/or permit higher yields and/or higher purity product.

Scheme 5

DMAP, toluene

Synthesis 1 3-Bromo-N-phenyl-benzenesulfonamide (3)

To a 30 gallon (-136 L) reactor was charged aniline (2) (4.01 kg; 93.13 g/mol; 43 mol), toluene (25 L), and 4-(dimethylamino)pyridine (DMAP) (12 g), and the mixture was heated to 50-60⁰C. 3-Bromobenzenesulfonyl chloride (1) (5 kg; 255.52 g/mol; 19.6 mol) was charged into the reactor over 30 minutes at 50-60⁰C and progress of the reaction was monitored by HPLC. After 19 hours, toluene (5 L) was added due to losses overnight through the vent line and the reaction was deemed to be complete with no compound (1) being detected by HPLC. The reaction mixture was diluted with toluene (10 L) and then quenched with 2 M aqueous hydrochloric acid (20 L). The organic and aqueous layers were separated, the aqueous layer was discarded, and the organic layer was washed with water (20 L), and then 5% (w/w) sodium bicarbonate solution (20 L), while maintaining the batch temperature at 45-55°C. The batch was then used in the next synthesis.

Synthesis 2 (E)-3-(3-Phenylsulfamoyl-phenyl)-acrylic acid ethyl ester (5)

To the batch containing 3-bromo-N-phenyl-benzenesulfonamide (3) (the treated organic layer obtained in the previous synthesis) was added triethylamine (2.97 kg; 101.19 g/mol; 29.4 mol), tri(o-tolyl)phosphine (119 g; 304.37 g/mol; 0.4 mol), and palladium (II) acetate (44 g; 224.51 g/mol; 0.2 mol), and the resulting mixture was degassed four times with a vacuum/nitrogen purge at 45-55°C. Catalytic palladium (0) was formed in situ. The batch was then heated to 80-90⁰C and ethyl acrylate (4) (2.16 kg; 100.12 g/mol; 21.6 mol) was slowly added over 2.75 hours. The batch was sampled after a further 2 hours and was deemed to be complete with no compound (3) being detected by HPLC. The batch was cooled to 45-55°C and for convenience was left at this temperature overnight.

The batch was then reduced in volume under vacuum to 20-25 L, at a batch temperature of 45-55°C, and ethyl acetate (20 L) was added. The batch was filtered and the residue washed with ethyl acetate (3.5 L). The residue was discarded and the filtrates were sent to a 100 gallon (-454 L) reactor, which had been pre-heated to 60⁰C. The 30 gallon (-136 L) reactor was then cleaned to remove any residual Pd, while the batch in the 100 gallon (-454 L) reactor was washed with 2 M aqueous hydrochloric acid and water at 45-55°C. Once the washes were complete and the 30 gallon (-136 L) reactor was clean, the batch was transferred from the 100 gallon (-454 L) reactor back to the 30 gallon (-136 L) reactor and the solvent was swapped under vacuum from ethyl acetate/toluene to toluene while maintaining a batch temperature of 45-55°C (the volume was reduced to 20-25 L). At this point, the batch had precipitated and heptanes (10 L) were added to re-dissolve it. The batch was then cooled to 0-10⁰C and held at this temperature over the weekend in order to precipitate the product. The batch was filtered and the residue was washed with heptanes (5 L). A sample of the wet-cake was taken for Pd analysis. The Pd content of the crude product (5) was determined to be 12.9 ppm.

The wet-cake was then charged back into the 30 gallon (-136 L) reactor along with ethyl acetate (50 L) and heated to 40-50⁰C in order to obtain a solution. A sparkler filter loaded with 12 impregnated Darco G60® carbon pads was then connected to the reactor and the solution was pumped around in a loop through the sparkler filter. After 1 hour, a sample was taken and evaporated to dryness and analysed for Pd content. The amount of Pd was found to be 1.4 ppm. A second sample was taken after 2 hours and evaporated to dryness and analysed for Pd content. The amount of Pd had been reduced to 0.6 ppm. The batch was blown back into the reactor and held at 40-50⁰C overnight before the solvent was swapped under vacuum from ethyl acetate to toluene while maintaining a batch temperature of 45-55°C (the volume was reduced to 20-25 L). At this point, the batch had precipitated and heptanes (10 L) were added to re-dissolve it and the batch was cooled to 0-10⁰C and held at this temperature overnight in order to precipitate the product. The batch was filtered and the residue was washed with heptanes (5 L). The filtrate was discarded and the residue was dried at 45-55°C under vacuum for 25 hours. A first lot of the title compound (5) was obtained as an off-white solid (4.48 kg, 69% overall yield from 3-bromobenzenesulfonyl chloride (1)) with a Pd content of 0.4 ppm and a purity of 99.22% (AUC) by HPLC.

Synthesis 3 (E)-3-(3-Phenylsulfamoyl-phenyl)-acrvlic acid (6)

To the 30 gallon (-136 L) reactor was charged the (E)-3-(3-phenylsulfamoyl-phenyl)- acrylic acid ethyl ester (5) (4.48 kg; 331.39 g/mol; 13.5 mol) along with 2 M aqueous sodium hydroxide (17.76 L; -35 mol). The mixture was heated to 40-50°C and held at this temperature for 2 hours before sampling, at which point the reaction was deemed to be complete with no compound (5) being detected by HPLC. The batch was adjusted to pH 2.2 using 1 M aqueous hydrochloric acid while maintaining the batch temperature between 40-50⁰C. The product had precipitated and the batch was cooled to 20-30⁰C and held at this temperature for 1 hour before filtering and washing the cake with water (8.9 L). The filtrate was discarded. The batch was allowed to condition on the filter overnight before being charged back into the reactor and slurried in water (44.4 L) at 40-50⁰C for 2 hours. The batch was cooled to 15-20°C, held for 1 hour, and then filtered and the residue washed with water (8.9 L). The filtrate was discarded. The crude title compound (6) was transferred to an oven for drying at 45-55°C under vacuum with a slight nitrogen bleed for 5 days (this was done for convenience) to give a white solid (3.93 kg, 97% yield). The moisture content of the crude material was measured using Karl Fischer (KF) titration and found to be <0.1% (w/w). To the 30 gallon (-136 L) reactor was charged the crude compound (6) along with acetonitrile (47.2 L). The batch was heated to reflux (about 80°C) and held at reflux for 2 hours before cooling to 0-10°C and holding at this temperature overnight in order to precipitate the product. The batch was filtered and the residue was washed with cold acetonitrile (7.9 L). The filtrate was discarded and the residue was dried under vacuum at 45-55°C for 21.5 hours. The title compound (6) was obtained as a fluffy white solid (3.37 kg, 84% yield with respect to compound (5)) with a purity of 99.89% (AUC) by HPLC.

Synthesis 4 (E)-N-Hvdroxy-3-(3-phenylsulfamoyl-phenyl)-acrylamide (PXD101) BELINOSTAT

To the 30 gallon (-136 L) reactor was charged (E)-3-(3-phenylsulfamoyl-phenyl)-acrylic acid (6) (3.37 kg; 303.34 g/mol; 11.1 mol) and a pre-mixed solution of 1 ,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in isopropyl acetate (IPAc) (27 g in 30 L; 152.24 g/mol; 0.18 mol). The slurry was stirred and thionyl chloride (SOCI₂) (960 mL; density ~1.631 g/mL; 118.97 g/mol; -13 mol) was added to the reaction mixture and the batch was stirred at 20-30⁰C overnight. After 18.5 hours, the batch was sampled and deemed to be complete with no compound (6) being detected by HPLC. The resulting solution was transferred to a 100 L Schott reactor for temporary storage while the

30 gallon (-136 L) reactor was rinsed with isopropyl acetate (IPAc) and water. Deionized water (28.9 L) was then added to the 30 gallon (-136 L) reactor followed by 50% (w/w) hydroxylamine (6.57 L; -1.078 g/mL; 33.03 g/mol; -214 mol) and another charge of deionized water (1.66 L) to rinse the lines free of hydroxylamine to make a 10% (w/w) hydroxylamine solution. Tetrahydrofuran (THF) (6.64 L) was then charged to the

30 gallon (-136 L) reactor and the mixture was stirred and cooled to 0-10⁰C. The acid chloride solution (from the 100 L Schott reactor) was then slowly charged into the hydroxylamine solution over 1 hour maintaining a batch temperature of 0-10°C during the addition. The batch was then allowed to warm to 20-30⁰C. The aqueous layer was separated and discarded. The organic layer was then reduced in volume under vacuum while maintaining a batch temperature of less than 30⁰C. The intention was to distill out 10-13 L of solvent, but this level was overshot. A larger volume of isopropyl acetate (IPAc) (16.6 L) was added and about 6 L of solvent was distilled out. The batch had precipitated and heptanes (24.9 L) were added and the batch was held at 20-30°C overnight. The batch was filtered and the residue was washed with heptanes (6.64 L). The filtrate was discarded and the residue was dried at 45-55°C under vacuum with a slight nitrogen bleed over the weekend. The title compound (PXD101) was obtained as a light orange solid (3.11 kg, 89% yield with respect to compound (6)) with a purity of 99.25% (AUC) by HPLC.

The title compound (PXD101) (1.2 kg, 3.77 mol) was dissolved in 8 volumes of 1:1 (EtOH/water) at 60⁰C. Sodium bicarbonate (15.8 g, 5 mol%) was added to the solution. Water (HPLC grade) was then added at a rate of 65 mL/min while keeping the internal temperature >57°C. After water (6.6 L) had been added, crystals started to form and the water addition was stopped. The reaction mixture was then cooled at a rate of 10°C/90 min to a temperature of 0-10^cC and then stirred at ambient temperature overnight. The crystals were then filtered and collected. The filter cake was washed by slurrying in water (2 x 1.2 L) and then dried in an oven at 45°C for 60 hours with a slight nitrogen bleed. 1.048 kg (87% recovery) of a light orange solid was recovered. Microscopy and XRPD data showed a conglomerate of irregularly shaped birefringant crystalline particles. The compound was found to contain 0.02% water.

As discussed above: the yield of compound (5) with respect to compound (1) was 69%. the yield of compound (6) with respect to compound (5) was 84%. the yield of PXD101 with respect to compound (6) was 89%.

PAPER

Synthetic Commun. 2010, 40, 2520-2524.

PATENT

FORMULATION

WO2006120456A1

Formulation Studies

These studies demonstrate a substantial enhancement of HDACi solubility (on the order of a 500-fold increase for PXD-101) using one or more of: cyclodextrin, arginine, and meglumine. The resulting compositions are stable and can be diluted to the desired target concentration without the risk of precipitation. Furthermore, the compositions have a pH that, while higher than ideal, is acceptable for use.

UV Absorbance

The ultraviolet (UV absorbance E\ value for PXD-101 was determined by plotting a calibration curve of PXD-101 concentration in 50:50 methanol/water at the λ_max for the material, 269 nm. Using this method, the E¹i value was determined as 715.7.

Methanol/water was selected as the subsequent diluting medium for solubility studies rather than neat methanol (or other organic solvent) to reduce the risk of precipitation of the cyclodextrin.

Solubility in Demineralised Water

The solubility of PXD-101 was determined to be 0.14 mg/mL for demineralised water. Solubility Enhancement with Cvclodextrins

Saturated samples of PXD-101 were prepared in aqueous solutions of two natural cyclodextrins (α-CD and γ-CD) and hydroxypropyl derivatives of the α, β and Y cyclodextrins (HP-α-CD, HP-β-CD and HP-γ-CD). All experiments were completed with cyclodextrin concentrations of 250 mg/mL, except for α-CD, where the solubility of the cyclodextrin was not sufficient to achieve this concentration. The data are summarised in the following table. HP-β-CD offers the best solubility enhancement for PXD-101.

Phase Solubility Determination of HP-β-CD

The phase solubility diagram for HP-β-CD was prepared for concentrations of cyclodextrin between 50 and 500 mg/mL (5-50% w/v). The calculated saturated solubilities of the complexed HDACi were plotted against the concentration of cyclodextrin. See Figure 1.

CLIP

SPECTRUM

Tiny Biotech With Three Cancer Drugs Is More Alluring Takeover Bet Now
Forbes
The drug is one of Spectrum’s two drugs undergoing phase 3 clinical trials. Allergan paid Spectrum $41.5 million and will make additional payments of up to $304 million based on achieving certain milestones. So far, Raj Shrotriya, Spectrum’s chairman, …

http://www.forbes.com/sites/genemarcial/2013/07/14/tiny-biotech-with-three-cancer-drugs-is-more-alluring-takeover-bet-now/

CLIP

PAPER

A practical synthetic route of belinostat is reported. Belinostat was obtained via a five-step process starting from benzaldehyde and including addition reaction with sodium bisulfite, sulfochlorination with chlorosulfonic acid, sulfonamidation with aniline, Knoevenagel condensation, and the final amidation with hydroxylamine. Key to the strategy is the preparation of 3-formylbenzenesulfonyl chloride using an economical and practical protocol. The main advantages of the route include inexpensive starting materials and acceptable overall yield. The scale-up experiment was carried out to provide 169 g of belinostat with 99.6% purity in 33% total yield.

(E)-N-Hydroxy-3-((phenylamino)sulfonyl)phenyl)acrylamide (Belinostat, 1)

1

mp 172–174 °C, (lit.(@) 172 °C). ¹H NMR (400 MHz, DMSO-d₆) δ = 10.75–10.42 (m, 2H), 9.15 (s, 1H), 7.92 (s, 1H), 7.78 (d, J = 7.8 Hz, 1H), 7.71 (d, J = 7.8 Hz, 1H), 7.56 (d, J = 7.8 Hz, 1H),7.47 (d, J = 15.8 Hz, 1H), 7.24 (m, 2H), 7.10–7.01 (m, 3H), 6.51 (d, J = 15.8 Hz, 1H). MS (ESI): m/z = 318.6 [M+H] ⁺.

@ Finn, P. W.; Bandara, M.; Butcher, C.; Finn, A.; Hollinshead, R.; Khan, N.; Law, N.; Murthy, S.; Romero,R.; Watkins, C.; Andrianov, V.; Bokaldere, R. M.; Dikovska, K.; Gailite, V.; Loza, E.; Piskunova, I.;Starchenkov, I.; Vorona, M.; Kalvinsh, I. Helv. Chim. Acta 2005, 88, 1630, DOI: 10.1002/hlca.200590129

Clip

Belinostat (Beleodaq),

Belinostat is a drug which was developed by Spectrum Pharmaceuticals and is currently marketed by Onxeo as Beleodaq. The
drug, which received fast track designation by the United States Food and Drug Administration (US FDA) and was approved for
the treatment of hematological malignancies and solid tumors associated with peripheral T-cell lymphoma (PTCL) in 2014,58 is a histone deacetylase (HDAC) inhibitor and is the third such treatment to receive accelerated approval for PTCL, the others being
vorinostat (Zolinza) and pralatrexate (Folotyn).58 Although belinostat was not yet approved in Europe as of August 2014,58 the
compound exhibits a safety profile considered to be acceptable for HDAC inhibitors–less than 25% of patients reported adverse
effects and these most frequently were nausea, fatigue, pyrexia,anemia, and emesis.58 While several different synthetic approaches
have been reported for the preparation of belinostat and related HDAC inhibitors,59–62 the most likely process-scale approach has
been described in a patent application filed by Reisch and co-workers at Topotarget UK, which exemplifies the synthesis described in
Scheme 8 on kilogram scale.63

Commercially available 3-bromobenzenesulfonyl chloride (41) was reacted with aniline in the presence of aqueous sodium carbonate
to deliver sulfonamide 42 in 94% yield. Next, this aryl bromide was subjected to a Heck reaction involving ethyl acrylate to
give rise to cinnamate ester 43, which was immediately saponified under basic conditions and acidic workup to furnish the corresponding acid 44. This acid was activated as the corresponding acid chloride prior to subjection to hydroxylamine under basic conditions to form the hydroxamic acid, which was then recrystallized from an 8:1 ethanol/water mixture in the presence of a catalytic
amount of sodium bicarbonate to furnish crystalline belinostat (VI) in 87% overall yield from acid 44.61

Lee, H. Z.; Kwitkowski, V. E.; Del Valle, P. L.; Ricci, M. S.; Saber, H.;Habtemariam, B. A.; Bullock, J.; Bloomquist, E.; Li Shen, Y.; Chen, X. H.;Brown, J.; Mehrotra, N.; Dorff, S.; Charlab, R.; Kane, R. C.; Kaminskas, E.;Justice, R.; Farrell, A. T.; Pazdur, R. Clin. Cancer Res. 2015, 21, 2666.
59. Qian, J.; Zhang, G.; Qin, H.; Zhu, Y.; Xiao, Y. CN Patent 102786448A, 2012.
60. Wang, H.; Yu, N.; Chen, D.; Lee, K. C.; Lye, P. L.; Chang, J. W.; Deng, W.; Ng, M.C.; Lu, T.; Khoo, M. L.; Poulsen, A.; ngthongpitag, K.; Wu, X.; Hu, C.; Goh, K.C.; Wang, X.; Fang, L.; Goh, K. L.; Khng, H. H.; Goh, S. K.; Yeo, P.; Liu, X.; Bonday, Z.; Wood, J. M.; Dymock, B. W.; Kantharaj, E.; Sun, E. T. J. Med. Chem.2011, 54, 4694.
61. Yang, L.; Xue, X.; Zhang, Y. Synth. Comm. 2010, 40, 2520.

 CLIP

 

 Helv Chim Acta 2005, 88(7), 1630-1657: It is first reported synthesis for Belinostat and many other derivatives. The procedure uses oleum, thionyl chloride (SOCl₂) as well as oxalyl chloride (COCl)₂, no wonder better procedures were derived from it. ABOVE
Synth Comm 2010, 40(17), 2520–2524: The synthesis avoids the use of the extremely corrosive oleum and thionyl chloride (SOCl₂) and therefore is possibly better for scaled-up production. Second, synthetic steps do not involve tedious separations and give a better overall yield.  BELOWIdentifications:

Experimental: ¹H NMR (300 MHz, DMSO-d₆): δ 6.52 (d, J=15.9 Hz, 1H), 6.81–7.12 (m, 6H), 7.33 (d, J=15.9 Hz, 1H), 7.47–7.67 (m, 3 H), 7.87 (s, 1H), 9.00–11.20 (br, 3H).

ANALYTICAL HPLC TEST METHOD

HPLC spectrum of Belinostat.

PATENT

http://www.google.si/patents/CN102531972A?cl=en

Belinostat synthesis process related to the first report of the literature of W002 / 30879 A2, including preparation for Belinostat described as follows:

Example 3:

3- (3-sulfonate-yl) phenyl – acrylate preparation:

First, 3-bromophenyl sulfonate 37. Ig (257. 90g / mol, 0. 1439mol) was dissolved with stirring in 260mL toluene IL reactor was then added triethylamine 36. 5g (101. 19g / mol, 0. 3604mol), tri (o-methylphenyl) phosphine 0. 875g (304. 37g / mol, 0. 002874mol), palladium acetate 0. 324g (224. 51g, 0. 001441mol), the reaction mixture was heated to 45- 55 ° C with nitrogen pumping ventilation four, this time in the reaction system to generate the catalytically active 1 ^ (0). The temperature of the reaction system was raised to 80-90 ° C, within 2. 75h dropwise methacrylate 13. 6g (86. 04g / mol, 0. 1586mol), the reaction was continued after the cell by HPLC 3- bromophenyl sulfonyl chloride was completion of the reaction. The temperature of the reaction system was reduced to 45-55 ° C.

[0021] In at 45-55 ° C, the reaction mixture was concentrated under reduced pressure, ethyl acetate and n-heptane and recrystallized to give the product 29. 4g, 83% yield.

[0022] The spectral data:

1HNMR (DMS0-d6, HMDS0), δ (ppm): 3. 65 (3H, S, H-1); 6. 47 (1H, d, J = 16 0 Hz, H-2.); 7. 30 -8 00 (5H, m, H-3, H_4, H_5, H_6, H_7) m / e:. 264. 23

Belinostat

Systematic (IUPAC) name
(2E)-N-Hydroxy-3-[3-(phenylsulfamoyl)phenyl]prop-2-enamide
Clinical data
Trade names	Beleodaq
AHFS/Drugs.com	beleodaq
Pregnancy category	US: D (Evidence of risk)
Routes of administration	Intravenous (IV)
Legal status
Legal status	US: ℞-only
Pharmacokinetic data
Bioavailability	100% (IV)
Protein binding	92.9–95.8%[1]
Metabolism	UGT1A1
Excretion	Urine
Identifiers
CAS Number	866323-14-0
ATC code	L01XX49 (WHO)
PubChem	CID 6918638
ChemSpider	5293831
UNII	F4H96P17NZ
ChEBI	CHEBI:61076
ChEMBL	CHEMBL408513
Synonyms	PXD101
Chemical data
Formula	C15H14N2O4S
Molar mass	318.348 g/mol

Pidotimod

H-Pyr-Thz-OH

(4R)-3-[(2S)-5-oxopyrrolidine-2-carbonyl]-1,3-thiazolidine-4-carboxylic acid

CAS 121808-62-6

Thymodolic acid, Pidotimod, Timodolic acid, PGT/1A, Axil, Onaka, Pigitil, Polimod

(4R)-3-(5-oxo-L-prolyl)-l ,3-thiazolidine-4-carboxylic acid,  ITI 231723.

3-(L-pyroglutamyl)-L-thiazolidine-4-carboxylic acid

• 4-Thiazolidinecarboxylic acid, 3-[(5-oxo-2-pyrrolidinyl)carbonyl]-, [R-(R*,S*)]-
• (4R)-3-[[(2S)-5-Oxo-2-pyrrolidinyl]carbonyl]-4-thiazolidinecarboxylic acid
• Adimod
• Axil (pharmaceutical)
• Pigitil

Stefano Poli, Corona Lucio Del

POLI INDUSTRIA CHIMICA S.p.A.

Pidotimod is an immunostimulant.^[1]

Pidotimod, whose chemical name is (4R)-3-(5-oxo-L-prolyl)-l ,3-thiazolidine-4-carboxylic acid, was first disclosed in ITI 231723. It is a synthetic peptide-like molecule provided with an in vitro and in vivo immunomodulating action (Giagulli et al., International Immunopharmacology, 9, 2009, 1366-1373). The immune system assists in maintaining a homeostatic balance between the human body and all foreign substances. An abnormality in this balance may cause a defective or aberrant response towards non-self substances, as well as loss of tolerance toward self-antigens, in such cases, the immune system imbalance exhibits clinically as signs of disease.

Pidotimod has been shown to induce dendritic cell maturation and up-regulate the expression of HLA-DR and co-stimulatory molecules CD83 and CD86, which are integral to communication with adaptive immunity cells. Pidotimod has also been shown to stimulate dendritic cells to release pro-inflammatory molecules such as MCP-1 and TNF-a cytokines, and to inhibit thymocyte apoptosis caused by a variety of apoptosis-inducing molecules. Pidotimod exerts a protective action against infectious processes, although not through direct antimicrobial or antiviral action. Rather, pidotimod stimulates both innate and acquired immunity by enhancing humoral and cell-mediated immunity mechanisms.

Pidotimod, which may be administered as solid or liquid forms, for example, via an oral route, has been shown to increase natural resistance to viral or bacterial infections in animal models. Efficacy demonstrated in patients includes respiratory, urinary and genital infections, in particular recurrent respiratory infections in pediatric patients, respiratory infections in asthmatic patients and chronic obstructive pulmonary disease in adults and elderly patients.

Besides exhibiting activity to illnesses characterized by immune defects, pidotimod has been reported to be of benefit in to patients with other kinds of diseases, not directly related to immune defects, including gastroenterology diseases such as ulcerative colitis and irritable bowel syndrome, and dermatological diseases such as psoriasis and atopic dermatitis where symptoms relating to these diseases have been attenuated. In gastroenterology diseases pidotimod may be administered either by oral or by rectal route. Oral route or topical application, for example in creams or gels containing pidotimod, may be used to treat dermal conditions.

Further use of pidotimod includes treatment of inflammatory diseases, in particular those characterized by an aberrant activation of the non-canonical NF-kB pathway. Diseases implicated by such activation include allergic diseases, autoimmune diseases, and numerous other inflammatory diseases. Allergic diseases include allergic rhinitis, allergic conjunctivitis, contact dermatitis, eczema and allergic vasculitis.

Autoimmune diseases include alopecia areata, ankylosing spondylitis, autoimmune cardiomyopathy, autoimmune connective tissue diseases, autoimmune enteropathy, autoimmune hepatitis, autoimmune peripheral neuropathy, autoimmune pancreatitis, autoimmune polyendocrine syndrome, autoimmune thrombocytopenic purpura, autoimmune urticaria, autoimmune uveitis, celiac disease, chronic fatigue syndrome, cystic fibrosis, hashimoto’s thyroiditis, idiopathic pulmonary fibrosis, idiopathic thrombocytopenic purpura, IGA nephropathy, juvenile idiopathic arthritis for juvenile rheumatoid arthritis, or Still’s disease) Kawasaki’s disease, lichen planus, lupus erythematosus, rheumatoid arthritis, rheumatic fever, Sj5gren’s syndrome, spondyloarthropathy, temporal arteritis (or giant cell arteritis), urticarial vasculitis, and vitiligo.

Other inflammatory diseases include Alzheimer’s disease, atherosclerosis, chronic liver diseases, chronic nephropathy, gastritis, glomerulonephritis, hydradenitis suppurativa, hypogammaglobulinemia, interstitial cystitis, lichen sclerosus, liver steatosis, metabolic syndrome, obesity, Parkinson’s disease, pemphigus vulgaris, post-ischemic inflammation, raynaud phenomenon, restless leg syndrome, retroperitoneal fibrosis, and thrombocytopenia.

PATENT

CN 104926922

Synthesis pidotimod

A method for producing pidotimod, characterized in that: comprising the steps of: a) L- thiazolidine-4-carboxylic acid: L- cysteine formaldehyde solution was added dropwise, stirred at room temperature, filtered to give L- thiazolidine-4-carboxylic acid; (2) metal ion load type cation exchange resin preparation: strongly acidic with hydrochloric acid cation exchange resin is converted to the hydrogen form, the hydrogen form strong acid cation exchange resin was added a solution of a metal ion compound In, 40 ~ 80 ° C for 1 to 6 hours, cooled to room temperature, and dried to obtain a supported metal ion cation exchange resin; (3) Synthesis of pidotimod: the step (1) of L- thiazolidine – 4- carboxylic acid, in step (2) of the load as a catalyst metal ion type cation exchange resin, L- pyroglutamic acid and N, N- dimethylformamide mixed, 40 ~ 80 ° C for 1 to 4 hours, filtered to give a white solid, the white solid was acidified with hydrochloric acid, to give the finished pidotimod.

In four flask IOg L- thiazolidine-4-carboxylic acid, 11. 3g g L- pyroglutamic acid, 320mL N, N- dimethylformamide, 12g modified resin, 70 ° C the reaction 2 hours. Filtration, the reaction mixture by rotary evaporation, after removal of part of the solvent, placed in an ice bath to cool, the precipitated solid was suction filtered to give a white solid, this white solid was acidified with 37% hydrochloric acid, was allowed to stand at KTC, crystallization, filtration, a white product 14. 4g, a yield of 78.3%. Measured melting point 192 ~ 194 ° C, [a] 25D = – 150 ° (literature values mp: 192 ~ 194 ° C, [a] 25D = – 150 °).The whole preparation reaction pidotimod total yield of 64%. By HPLC, pidotimod content of 98.5%.

PAPER

Zhang, Yi; Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences 2009, 877(24), PG 2566-2570

http://europepmc.org/abstract/med/19604731

10.1016/j.jchromb.2009.06.038

PATENT

WO2016113242,

Example 14 – Preparation of Pidotimod

Pidotimod was prepared following Example 1 of EP0422566 Al .

PATENT

WO2015036009,

https://www.google.com/patents/WO2015036009A1?cl=en

PATENT

EP276752,

PATENT

http://google.com/patents/EP0422566B1?cl=en

EXAMPLE 1

A solution of 16.78 g (0.084 mole) of ethyl L-thiazolidine-4-carboxylate hydrochloride in 33 ml of water is treated with 16.78 g of potassium carbonate and extracted with 40 ml of ethyl acetate. The organic phase is dried over sodium sulfate, filtered and diluted to 85 ml with ethyl acetate. The solution is stirred and cooled to 0-5°C, then 19.2 g (0.093 mole) of dicyclohexylcarbodiimide dissolved in 20 ml of ethyl acetate and 12 g (0.093 mole) of L-pyroglutamic acid are added thereto. The reaction mixture is stirred for 1 hour at 0-5°C, then 12 hours at room temperature, dicyclohexylurea is filtered, the filtrate is evaporated under vacuum and the oily residue, consisting in ethyl 3-(L-pyroglutamyl)-L-thiazolidine-4-carboxylate is taken up into 25 ml of water. 3.73 g of sodium hydroxide dissolved in 13.3 ml of water are dropped into the resulting solution. After 30 minutes, the reaction mixture is acidified with concentrated hydrochloric acid at 0-5°C, kept for 2 hours at 5°C, then filtered washing with little cool water and dried to obtain 17.8 g (87.6%) of 3-(L-pyroglutamyl)-L-thiazolidine-4-carboxylic acid, m.p. 193-194°C.

EXAMPLE 2

23 g (0.1 mol) of L-N-t-butoxycarbonylpyroglutamic acid (E. Schröder and E. Klinger, Ann. Chem., 673, 1964, 202) and 16.1 g (0.1 mol) of ethyl L-thiazolidine-4-carboxylate are dissolved in 150 ml of THF, to the solution stirred at 0-5°C, 21 g (0.105 mol) of dicyclohexylcarbodiimide are added and the slurry is stirred for 15 hours at room temperature. The dicyclohexylurea is filtered, the wear filtrate is evaporated u.v. and the oily residue is kept in 40 ml of water. In the solution 6.6 g of potassium hydroxyde in a little water are dropped in 30′ at 15-20°C, the pH is adjusted to 2 with hydrochloric acid at 0-5°C and after 2 hours the precipitated L-pyroglutamyl-L-thiazolidine-4-carboxylic acid is filtered and dried, giving 88%, mp. 193-4°.

CLIP

Drugs Fut 1991,16(12),1096

Liebigs Ann Chem 1964,673

The synthesis of pidotimod has been carried out using N-tert-butoxycarbonyl-L-pyroglutamic acid as starting material, in order to avoid the formation of diketopiperazine derivatives. L-Glutamic acid (I) was condensed with di-tert-butyl dicarbonate by means of triethylamine in DMF to give N-(tert-butoxycarbonyl)-L-glutamic acid (II), which is dissolved in THF and treated with dicyclohexylcarbodiimide (DCC) to obtain N-(tert-butoxycarbonyl)-L-glutamic anhydride (III). The treatment of anhydride (III) with dicyclohexylamine in THF-ethyl ether affords the dicyclohexylamine salt of N-(tert-butoxycarbonyl)-L-pyroglutamic acid (IV), which by acidification with aqueous citric acid yields the corresponding free acid (V). The condensation of equimolecular amounts of N-(tert-butoxycarbonyl)-L-pyroglutamic acid (V) with L-thiazolidine-4-carboxylic acid ethyl ester (VIII) by means of DCC in methylene chloride gives the coupled ester (IX), which is hydrolyzed with aqueous NaOH, and the corresponding sodium salt acidified to yield the N-tert-butoxycarbonyl derivative (X). Finally, this compound is deprotected with trifluoroacetic acid to obtain crystalline pidotimod (XI). The intermediate thiazolidine (VIII) has been obtained as follows: Esterification of L-thiazolidine-4-carboxylic acid (VI) with ethanol by means of SOCl2 gives the corresponding ethyl ester hydrochloride (VII), which by treatment with K2CO3 in water yields the free ester (VIII).

CLIP

Arzneim-Forsch Drug Res 1994,44(12a),1402

Two new related routes for the synthesis of pidotimod have been reported: 1) The condensation of L-pyroglutamic acid (I) with L-thiazolidine-4-carboxylic acid ethyl ester (II) by means of dicyclohexylcarbodiimide (DCC) in methylene chloride gives the corresponding dipeptide ethyl ester (III), which is saponified with aqueous 1N NaOH. 2) By condensation of the activated ester L-pyroglutamic acid pentachlorophenyl ester (IV) with L-thiazolidine-4-carboxylic acid (V) by means of triethylamine in DMF.

PATENT

WO-2016112977

Novel crystalline, amorphous and solid forms of di-pidotimod benzathine (designated as Forms M and H), their hydrates, processes for their preparation and compositions comprising them are claimed. Also claimed is their use for treating viral or bacterial infections, respiratory, urinary and/or genital infections, ulcerative colitis, irritable bowel syndrome, psoriasis and atopic dermatitis

Example 14 – Preparation of Pidotimod

Pidotimod was prepared following Example 1 of EP0422566 Al .

NMR

Figure 17 is a Ή solution-state NMR spectrum of Form H

SEE

CN 104447947

Indian Pat. Appl. (2014), IN 2013MU00181 A

WO 2014111957

CN 103897025

References

Pidotimod

Systematic (IUPAC) name
(4R)-3-(5-oxo-L-prolyl)-1,3-thiazolidine-4-carboxylic acid
Clinical data
AHFS/Drugs.com	International Drug Names
Identifiers
ATC code	L03AX05 (WHO)
PubChem	CID 65944
ChemSpider	59348
UNII	785363R681
KEGG	D07261
ChEMBL	CHEMBL1488165
Synonyms	(4R)-3-[(2S)-5-oxopyrrolidine-2-carbonyl]-1,3-thiazolidine-4-carboxylic acid
Chemical data
Formula	C9H12N2O4S
Molar mass	244.26758 g/mol

//////////////Pidotimod, Thymodolic acid, Pidotimod, Timodolic acid, PGT/1A, Axil, Onaka, Pigitil, Polimod, H-Pyr-Thz-OH,  121808-62-6, ITI 231723, peptide, QA-7522, SMR000466390, Thymodolic acid, Timodolic acid, UNII:785363R681, 匹多莫德 , пидотимод ,  بيدوتيمود ,

O=C(O)[C@H]2N(C(=O)[C@H]1NC(=O)CC1)CSC2

WO 2016113372

Carbotegravir, New Patent, WO 2016113372, Lek Pharmaceutical and Chemical Co DD

LEK PHARMACEUTICALS D.D. [SI/SI]; Verovskova 57 1526 Ljubljana (SI)

MARAS, Nenad; (SI).
SELIC, Lovro; (SI).
CUSAK, Anja; (SI)

ViiV Healthcare is developing cabotegravir (first disclosed in WO2006088173), which in July 2016, was reported to be in phase 2 clinical development.

WO-2016113372

Process for preparing integrase inhibitors such as dolutegravir and cabotegravir and their analogs, useful for treating viral infections eg HIV infection. Also claims a process for preparing intermediates of dolutegravir and cabotegravir.

(4R, 12aS)-N-[(2,4-Difluorophenyl)methyl]-3 ,4,6,8, 12, 12a-hexahydro-7-hydroxy-4-methyl-6,8-dioxo-2H-pyrido[1 ‘,2’:4,5]pyrazino[2, 1-b][1 ,3]oxazine-9-carboxamide (Formula A):

Formula A

known by the INN name dolutegravir, is a new efficient antiviral agent from the group of HIV integrase inhibitors which is used in combination with some other antiviral agents for treatment of HIV infections, such as AIDS. The compound, which belongs to condensed polycyclic pyridines and was first disclosed in WO2006/1 16764, is marketed.

Another compound disclosed in WO2006/1 16764 is (3S, 1 1 aR)-N-[(2,4-difluorophenyl)methyl]-6-hydroxy-3-methyl-5,7-dioxo-2,3,5,7, 1 1 ,1 1 a-hexahydro[1 ,3]oxazolo[3,2-a]pyrido[1 ,2-d]pyrazine-8-carboxamide (Formula

Formula C

known by the INN name cabotegravir.

The complex structures of dolutegravir and cabotegravir present a synthetic challenge. The first description of the synthesis in WO2006/1 16764 shows a 16-steps synthesis (see Scheme A), which is industrially impractical due to its length and low overall yield.

Scheme A

WO 2010/068253 and WO 2006/1 16764 describe an alternative synthesis. The 1 1 -step synthesis, shown in Scheme B1 and Scheme B2, is based on bromination of the 9-position for further introduction of the carboxylic group. The synthesis relies on the use of expensive palladium catalysts and toxic selenium compounds. Furthermore, some variations of these approaches involve pyrone intermediates in several steps. In some cases pyrones are liquids which can complicate purification, while further reactions form complex mixtures.

doiutegravir

Scheme B2

In further alternative syntheses, acetoacetates were used as starting materials. Such an approach is challenging in terms of introducing the hydroxy group in the 7-position. The variation in Scheme C1 , described in WO2012/018065, starts from 4-benzyloxyacetoacetate. The procedure requires 9 steps, but use expensive reagents like palladium catalysts. Moreover, there is described a possibility of formation a co-crystal between an intermediate and hydroquinone, wherein however the additional step may diminish yields and make the process longer and time consuming.

Scheme C1

The variation in Scheme C2, described in WO2012/018065, starts from 4-chloroacetoacetate. The process is not optimal because of problems in steps which include pyrones and because of problems with conversion of 7-chloro to 7-hydroxy group which includes a disadvantageous use of silanolates with low yield (25%).

Scheme C2

The variation in Scheme C3, described in WO201 1/1 19566, starts from unsubstituted acetoacetate. For the introduction of the 7-hydroxy group, bromination is used and substitution of bromo with hydroxy is performed by a use of silanolates. The substitution of the bromine is achieved in a 43% yield.

Scheme C3

The variation in Scheme C4, described in WO201 1/1 19566, starts from 4-methoxyacetoacetate aiming at preparing dolutegravir or cabotegravir. The process uses lithium bases to affect a difficult to control selective monohydrolysis of a diester.

The object of the present invention is to provide short, simple, cost-effective, environmentally friendly and industrially suitable processes for beneficially providing dolutegravir and analogues thereof and cabotegravir and analogues thereof, in particular dolutegravir.

Scheme 1

According to an embodiment of the process of the invention the building block 3-aminobutanol can suitably be substituted with other aminoalcohols to give dolutegravir analogues. For example, using (S)-alaninol gives cabotegravir as the final product. Similarly, using amines other than 2,4-difluorobenzylamine in the amidation step results in the synthesis of other dolutegravir analogues.

According to the another preferred embodiment cabotegravir or a pharmaceutically acceptable salt thereof is prepared by the analogue process, which comprises providing a compound of formula (5c)

5c

converting the compound of formula (5c) to a compound of formula (6c)

6c

by carrying out a chlorination reaction, and converting the compound of formula (6c) to cabotegravir and/or a pharmaceutically acceptable salt thereof.

The compound of formula (5c) can preferably be provided by converting a compound of formula (3) to a compound of formula (4c)

Scheme 2

1. ) EtOCOCI, Et₃N / Me₂CO

2. ) 2,4-difiuorobenzylamine

Scheme 3

Analogous compound of formula 7c is a useful intermediate in the synthesis of cabotegravir. Scheme 3a

Scheme 4

Examples

The following examples are merely illustrative of the present invention and they should not be considered as limiting the scope of the invention in any way. The examples and modifications or other equivalents thereof will become apparent to those versed in the art in the light of the present entire disclosure. Particularly, all Examples related to the preparation of dolutegravir and intermediates thereof can be used by the analogy for the preparation of cabotegravir and intermediates thereof.

Example 1 :

Methyl acetoacetate (1 , 25.22 g) and dimethylformamide dimethyl acetal (DMFDMA, 35 mL) was heated at 50-55°C for 2 h, then methanol (60 mL), aminoacetaldehyde dimethyl acetal (24 mL) and acetic acid (4 mL) was added an the mixture was heated under reflux for one hour, then concentrated. MTBE (100 mL) was added and the mixture was kept at 5 °C overnight to crystallize. Upon filtration 46 g (92%) of product 2 was recovered.

¹H NMR (DMSO-d₆): δ 2.31 (s, 3H), 3.30 (s, 6H), 3.49 (m, 2H), 3.61 (s, 3H), 4.43 (m, 1 H), 8.02 (d, 1 H), 10.8 (bs, 1 H). ¹³C NMR (DMSO-d₆): δ 30.52, 35.48, 50.53, 54.23, 98.99, 102.47, 160.70, 166.92, 197.21 .

Example 2:

Compound 2 (5.00 g) was dissolved in 2-propanol, dimethyl oxalate (7.02 g) was added and heated to 40 °C. Sodium methylate (25% in methanol; 20 mL) was slowly (10 min) added, the mixture was then heated to 50-55 °C and stirred at that temperature for 2-2.5 h. The mixture was cooled to ambient temperature, then sodium hydroxide solution (1 M, 65 mL) was added to the mixture and stirred for another 2 h, followed by addition of concentrated hydrochloric acid (1 1 mL) and stirred for another 2 h. The precipitate was filtered and dried to give 8.08 g (NMR assay 47%; 65% yield) of compound 3.

¹H NMR (DMSO-d₆): δ 2.50 (m, 2H), 3.30 (s. 6H), 4.49 (m, 1 H), 7.06 (s, 1 H); 8.70 (s, 1 H). ¹³C NMR (DMSO-d₆): δ 55.23, 55.37, 102.34, 1 15.47, 120.24, 145.17, 162.71 , 165.22, 178.55.

Example 3:

Compound 2 (158.37 g) was dissolved in methanol (548 mL), followed by the addition of dimethyl oxalate (202.2 g). While keeping the temperature below 30°C, potassium ferf-butoxide (192.1 g) was added and reaction mixture was heated at 50 °C overnight. The suspension was then filtered and the filter cake washed with methanol. The filtrate was concentrated (approximately to 680 mL), then water (680 mL) was added, followed by addition of lithium hydroxide hydrate (143.7 g) while keeping the temperature below 40 °C. The suspension was then stirred at ambient temperature overnight and filtered. To the obtained filtrate, concentrated hydrochloric acid (339 mL) was added while keeping the temperature below 30 °C. The suspension was aged for 2 h and filtered to give 4 as a white powder (95.6 g, NMR assay 100%; 52% yield).

Example 4:

Compound 2 (5.00 g) was dissolved in 2-propanol, dimethyl oxalate (7.02 g) was added and heated to 40 °C. Sodium methylate (25% in methanol; 15 mL) was slowly (10 min) added then the mixture was heated to 50-55 °C and stirred at that temperature for 72 h. The mixture was concentrated and components were separated by flash column chromatography (ethyl acetate/methanol 9:1 to 6:4). Early fractions gave compound 22 upon concentration, late fractions gave compound 23.

Compound 22: ¹H NMR (DMSO-d₆): δ 2.49 (m, 2H), 3.28 (s, 6H), 3.73 (s, 3H), 3.85 (s, 3H), 4.41 (m, 1 H), 4.50 (m, 1 H), 6.65 (s, 1 H), 8.36 (s, 1 H). ¹³C NMR (DMSO-d₆): δ 51.63, 53.36, 54.25, 55.47, 102.71 , 1 18.24, 123.60, 140.81 , 150.21 , 162.44, 164.49, 173.43.

Compound 23: ¹H NMR (DMSO-d₆): δ 2.49 (m, 2H), 3.26 (s, 6H); 3.70 (s, 3H); 4.33 (d, 1 H); 4.60 (m, 1 H), 6.19 (s, 1 H), 8.12 (s, 1 H). ¹³C NMR (DMSO-d₆): δ 50.03, 51.34, 54.59, 54.85, 102.91 , 1 16.04, 1 18.19, 148.32, 152.12, 163.46, 165.24, 174.99

Example 5:

Compound 3 (5.5 g; assay 53%) was suspended in acetonitrile, acetic acid (6 mL) and methanesulfonic acid (2.5 mL) were added followed by the heating of mixture to 70 °C for 4 h. The suspension was filtered and filtrate cooled to ambient temperature. Triethylamine (6.6 mL) and (R)-3-amino-butan-1 -ol (1.24 mL) was added followed by heating the mixture at reflux temperature for 20-24 h. The mixture was filtered, filtrate concentrated and 1 M HCI (100 mL) was added, followed by extraction with dichloromethane (3 x 50 mL). Combined organic fractions were concentrated, 2-propanol was added (10 mL) and suspension was stirred at 70-80 °C for 10 min, left to cool to ambient temperature then filtered to give 2.19 g of compound 4 (73%).

¹H NMR (DMSO-de): δ 1.31 (d, 3H), 1.52 (m, 1 H), 1 .97 (m, 1 H), 3.89 (m, 1 H), 4.01 (m, 1 H), 4.46 (m, 1 H), 4.64 (m, 1 H), 4.78 (m, 1 H), 5.50 (m, 1 H), 7.29 (s, 1 H), 8.88 (s, 1 H), 15.83 (s, 1 H). ¹³C NMR (DMSO-d₆): δ 15.22, 29.14, 45.26, 51.13, 62.09, 76.03, 1 16.31 , 1 18.79, 140.53, 146.79, 155.36, 165.24, 178.75.

Example 6:

Compound 3 (14.55 g; assay 49%) was suspended in acetonitrile (125 mL), acetic acid (15 mL) and methanesulfonic acid (6.25 mL) were added followed by the heating of mixture to 70 °C for 4 h. The suspension was filtered and filtrate cooled to ambient temperature. Triethylamine (16.5 mL) and (S)-2-aminopropanol (2.45 mL) was added followed by heating the mixture at reflux temperature for 24 h. The insoluble product was filtered, washed with 2-propanol (20 mL) and dried to give (3S, 1 1 aR)-3-methyl-5,7-dioxo-2,3,5,7, 1 1 ,1 1 a-hexahydrooxazolo[3,2-a]pyrido[1 ,2-d]pyrazine-8-carboxylic acid (5.2 g, 75%).

¹H NMR (DMSO-d₆): δ 1.31 (d, J = 6.3 Hz, 3H), 3.65 (dd, J = 8.6, 6.8 Hz, 1 H), 4.13 (dd, J = 1 1.7, 10.3 Hz, 1 H), 4.28 (m, 1 H), 4.39 (dd, J = 8.6, 6.8 Hz, 1 H), 4.92 (dd, J = 12.3, 4.2 Hz, 1 H), 5.45 (dd, J = 10.2, 4.1 Hz, 1 H), 7.16 (s, 1 H), 8.84 (s, 1 H), 15.74 (s, 1 H).

Example 7:

Compound 4 (0.63 g) was dissolved in dichloromethane (15 mL), cooled to 5°C, then triethylamine (0.31 mL) was added, followed by ethyl chloroformate (0.26 mL), followed by slow (30 min) addition of 2,4-difluorobenzylamine. The mixture was then stirred at ambient temperature for 24 h. Water (10 mL) was added, organic phase was separated and washed with 1 M HCI (15 mL) and water (15 mL), concentrated and treated with 2-propanol to give the product 5 in a quantitative yield.

¹H NMR (CDCI₃): δ 1.39 (d, 3H), 1.52 (s, 1 H), 2.19 (m, 1 H), 4.00 (m, 2H), 4.16 (m, 1 H), 4.31 (m, 1 H), 4.62 (d, 2H), 5.00 (m, 1 H), 5.27 (m, 1 H), 6.80 (m 2H), 7.33 (m, 2H), 8.49 (s, 1 H), 10.48 (s, 1 H). ¹³C NMR (CDCI₃): 15.50, 29.22, 36.43, 45.19, 51.83, 62.79, 103.71 , 103.91 , 1 1 1 .0, 1 1 1 .18, 120.59, 123.04, 130.40, 137.41 , 144.58, 156.27, 163. 87, 177.83.

Example 8:

To a suspension of 4 (2.84 g, 10 mmol) in a mixture of triethylamine (2.24 mL, 16 mmol) and acetone (50 mL) stirring on an ice bath was added ethyl chloroformate (1 .20 mL, 12 mmol). After stirring for 10 min, 2,4-difluorobenzylamine (1.21 mL, 10 mmol) was added and the mixture left stirring at room temperature for 1 h. The product was isolated by slowly diluting the reaction mixture with water (50 mL), partial concentration, filtration, washing with water (2 50 mL) and drying. There was obtained 5 as a white powder (3.48 g, 86%): mp 181.0-184.7 °C. ¹H NMR (DMSO-d₆): δ 1.29 (d, J = 7.0 Hz, 3H), 1 .56 (dd, J = 13.9, 2.0 Hz, 1 H), 1 .93-2.06 (m, 1 H), 3.90 (ddd, J = 1 1.6, 5.0, 2.1 Hz, 1 H), 3.98 (td, J = 12.0, 2.2 Hz, 1 H), 4.45 (dd, J = 13.6, 6.6 Hz, 1 H), 4.72 (dd, J = 13.6, 3.8 Hz, 1 H), 4.74-4.81 (m, 1 H), 5.44 (dd, J = 6.6, 3.8 Hz, 1 H), 8.93 (s, 1 H), 15.14 (s, 1 H). ¹³C NMR (DMSO-d₆): δ 15.78, 29.13, 44.89, 52.88, 61 .63, 75.61 , 1 13.54, 128.49, 136.42, 145.64, 154.62, 164.58, 174.58

Example 9:

To a suspension of 4 (1 1.36 g, 40 mmol) in acetonitrile (80 mL) stirring at room temperature was added TCCA (9.29 g, 38 mmol) and DABCO (0.23 g, 5 mol%). After stirring at room temperature for 1 h, the reaction was quenched with a mixture of DMSO (5.26 mL) and water (1.33 mL). The insoluble cyanuric acid was removed by filtration and the filtrate evaporated under reduced pressure to give viscous oil. This was triturated in methanol (20 mL) to induce crystallization. The product was filtered, washed with cold methanol (10 mL) and dried to give 7 as a yellowish powder (5.13 g, 41 %): mp 191 .3-198.7 °C.

Example 10:

Attempted chlorination of 23: Compound 23 (0.54g) was suspended in acetonitrile (10 mL) and trichlorocyanuric acid (0.44 g) was added and the solution was stirred at ambient temperature overnight. Precipitate was filtered. Only traces of a product corresponding to the compound 26 could be detected in the reaction mixture by LC-MS analysis. Conversion did not improve with time.

Example 11 :

Attempted chlorination of 3: Compound 3 (0.30 g) was suspended in acetonitrile (5 mL) and trichlorocyanuric acid (0.13 g) was added. The suspension was stirred at ambient temperature overnight. Only traces of a product corresponding to the compound 24 could be detected in the reaction mixture by LC-MS analysis.

Example 12:

9 10

Trichloroisocyanuric acid (0.23 g) was added in a single portion to a stirred solution of the diethyl 1 -(2,2-dimethoxyethyl)-4-oxo-1 ,4-dihydropyridine-2,5-dicarboxylate (9, 0.66 g) in dry acetonitrile (4 mL) at room temperature. The resulting suspension was stirred at room temperature for ca. 24 h. The reaction mixture was diluted with dichloromethane and filtrated. The filtrate was then concentrated in vacuo to afford crude oil (0.86 g). Purification by flash chromatography (eluting ethyl acetate/cyclohexane) furnished diethyl 3-chloro-1 -(2,2-dimethoxyethyl)-4-oxo-1 ,4-dihydropyridine-2,5-dicarboxylate, 10 as a yellow semi-solid (0.38 g). ¹H NMR (CDCI₃): δ 1.28 (t, J=7A Hz, 3H), 1 .37 (t, J=7.2 Hz, 3H), 3.35 (s, 6H), 3.89 (d, J=5.0 Hz, 2H), 4.27 (q, J=l A Hz, 2H), 4.43 (q, J=l A Hz, 2H), 4.48 (t, J=4.9 Hz, 1 H), 8.15 (s, 1 H). ¹³C NMR (CDCI₃): δ 13.83, 14.13, 55.82, 57.09, 61.41 , 63.72, 102.52, 1 17.35, 126.90, 140.22, 146.92, 160.67, 164.13, 168.95.

Example 13:

Diethyl 1 -(2,2-dimethoxyethyl)-4-oxo-1 ,4-dihydropyridine-2,5-dicarboxylate (9, 0.64 g) was dissolved in anhydrous acetonitrile (6 mL) and treated sequentially with acetic acid (560 μί) and methanesulfonic acid (40 μί). The resulting mixture was heated to 62 °C and stirred for 4 h and more methanesulfonic acid (40 μΙ_) was added. After additional 2 h, more methanesulfonic acid (80 μΙ_) was added. This was repeated after additional 2 h, when more methanesulfonic acid (80 μΙ_) was added. The reaction mixture was stirred additional 17 h at 62 °C then was treated with a mixture of (R)-3-aminobutanol (0.22 g), triethylamine (0.5 mL) and acetonitrile (0.7 mL). The reaction mixture was stirred additional 22 h at 62 °C and then concentrated in vacuo. The crude material was partitioned between dichloromethane and 1 M HCI solution (15 mL). The combined organic phases were dried (Na₂S0₄), filtered and concentrated in vacuo to afford the crude (4R, 12aS)-ethyl 4-methyl-6,8-dioxo-3,4,6,8, 12,12a-hexahydro-2H-pyrido[1 ‘,2’:4,5]pyrazino[2, 1 -b][1 ,3]oxazine-9-carboxylate (11 ) as a brownish oil (0.61 g).

¹H NMR (CD₃OD): δ 8.44 (s, 1 H), 7.16 (m, 1 H), 5.48 (t, J=4.8 Hz, 1 H), 4.86 (m, 1 H), 4.49 (dd, J=13.6, 4.0 Hz, 1 H), 4.30-4.25 (m, 3H), 4.09 (dt, J=12.1 , 2.3 Hz, 1 H), 3.96 (ddd, J=1 1.7, 5.0, 2.1 Hz, 1 H), 2.18-2.10 (m, 1 H), 1.60-1 .56 (m, 1 H) 1 .39 (d, J=7A Hz, 3H), 1.33 (t, J=7A Hz, 3H). ¹³C NMR (CDCI₃): δ 8.45, 14.08, 15.39, 29.17, 45.04, 45.72, 51 .56, 60.86, 62.61 , 76.33, 1 19.54, 123.72, 136.96, 145.67, 156.26, 163.68, 175.43

Example 14:

¹⁰

Diethyl 3-chloro-1 -(2,2-dimethoxyethyl)-4-oxo-1 ,4-dihydropyridine-2,5-dicarboxylate (10, 1.23 g) was dissolved in 85% formic acid (25 mL) at room temperature. The mixture was warmed to 40 °C and stirred for 23 h. The reaction mixture was concentrated in vacuo, and then partitioned between dichloromethane and aqueous NaHC0₃ solution. The combined organic phases were dried (Na₂S0₄), filtered and concentrated in vacuo to afford brownish oil (0.49 g). The crude oil was dissolved in anhydrous toluene (5 mL) and treated sequentially with (R)-3-aminobutanol (0.19 g), methanol (0.2 mL) and acetic acid (96 μί). The resulting mixture was heated to 90 °C and stirred for 20 h. The reaction mixture was cooled to room temperature and then partitioned between dichloromethane and aqueous NaHC0₃ solution. The combined organic phases were dried (Na₂S0₄), filtered and concentrated in vacuo to afford the crude (4R,12aS)-Ethyl 7-chloro-4-methyl-6,8-dioxo-3,4,6,8,12, 12a-hexahydro-2H-pyrido[1 ‘,2’:4,5] pyrazino [2, 1-b][1 ,3]oxazine-9-carboxylate (12) as a brownish oil (0.24 g).

Example 15:

To a solution of 4 (5.68 g, 20 mmol) in dichloromethane (50 mL) stirring in an ice bath was added triethylamine (5.6 mL, 40 mmol), followed by ethyl chloroformate (2.61 mL, 26 mmol). After 20 min, ethanol (50 mL) was added. The mixture was then left stirring 24 h at room temperature and concentrated under reduced pressure. The residue was triturated in acetone (80 mL). The insoluble salt (triethylamine hydrochloride) was removed by filtration. The filtrate was evaporated under reduced pressure to give 11 as an amorphous solid in a quantitative yield (6.1 g).

Example 16:

To a stirring solution of 11 (0.94 g, 3.0 mmol) in acetonitrile (8 mL) heated at 40 °C was added TCCA in portions during 1 h (0.44 g, 1 .8 mmol). After an additional 1 h, the reaction mixture was diluted with a solution of NaHS0₃ (0.60 g) in water (60 mL), extracted with dichloromethane (50 mL) and the extract evaporated under reduced pressure to give a crude product which was purified by flash chromatography (CH₂CI₂ : MeOH, from 98 : 2 to 80 : 20) to give 12 (0.45 g, 44%).

¹H NMR (CDCI₃): δ 1.37 (t, J = 7.1 Hz, 3H), 1.38 (d, J = 7.0 Hz, 3H), 1 .56 (dq, J = 13.9, 2.2 Hz, 1 H), 2.21 (m, 1 H), 3.99 (d, J = 2.3 Hz, 1 H), 4.00 (t, J = 1.8 Hz, 1 H), 4.10 (dd, J = 13.2, 6.6 Hz, 1 H), 4.37-4.27 (m, 3H), 4.98 (m, 1 H), 5.35 (dd, J = 6.6, 3.8 Hz, 1 H), 8.07 (s, 1 H).

¹³C NMR (CDCI₃): δ 14.20, 16.09, 29.34, 44.87, 53.73, 61.49, 62.29, 76.01 , 1 16.22, 133.1 1 , 134.18, 144.52, 155.48, 163.88, 169.98.

Example 17:

To a mixture of 7 (3.89 g, 12.2 mmol) in methanol (12 mL) was added sodium methylate (22.3 mL, 97.6 mmol). The reaction mixture was stirred for 24 h at 30 °C and then quenched with a slow addition of 3M hydrochloric acid (35 mL) while stirring in an ice bath. The mixture was concentrated under reduced pressure to remove most of the methanol, then extracted with dichloromethane (2 30 mL), the combined extracts washed with water (30 mL) and evaporated under reduced pressure. Methanol (20 mL) was added to the obtained amorphous residue and removed under reduced pressure to yield the solid 8 (3.69 g, 98%).

¹H NMR (CDCI₃): δ 15.04 (s, 1 H), 8.42 (s, 1 H), 5.29 (dd, J=5.6, 3.9 Hz, 1 H), 5.01 -4.96 (m, 1 H), 4.42 (dd, J=13.6, 3.6 Hz, 1 H), 4.25 (dd, J=13.6, 6.0 Hz, 1 H), 4.05 (s, 3H), 4.00-3.97 (m, 2H), 2.21 -2-14 (m, 1 H), 1.53 (dd, J=14.1 , 1.9 Hz, 1 H), 1.36 (d, J=7 Hz, 3H). ¹³C NMR (CDCI₃): δ 176.35, 165.94, 155.03, 153.70, 143.08, 130.90, 1 15.94, 76.05, 62.65, 61.45, 53.86, 44.96, 29.43, 16.06.

Example 18:

To a suspension of 7 (2.55 g, 8.0 mmol) in a mixture of triethylamine (1 .46 mL, 10.4 mmol) and acetone (32 mL) stirring on an ice bath was added ethyl chloroformate (0.88 mL, 8.8 mmol). After stirring for 10 min, 2,4-difluorobenzylamine (1.07 mL, 8.8 mmol) was added and the mixture left stirring at room temperature for 1 h. The product was isolated by slowly diluting the reaction mixture with water (40 mL), filtration, washing with water (2 30 mL) and drying. There was obtained 2.91 g of 6 as a white powder (83%).

¹H NMR (CDCI₃): δ 1.30 (d, J = 7.0 Hz, 3H), 1 .49 (dd, J = 14.0, 2.2 Hz, 1 H), 2.14 (ddd, J = 14.6, 1 1.1 , 6.4 Hz, 1 H), 3.89-3.95 (m, 2H), 4.09-4.15 (m, 1 H), 4.26 (dd, J = 13.4, 3.8 Hz, 1 H), 4.55 (d, J = 5.8 Hz, 2H), 4.89-4.98 (m, 1 H), 5.18 (dd, J = 6.2, 3.8 Hz, 1 H), 6.68-6.79 (m, 2H), 7.23-7.31 (m, 1 H), 8.41 (s, 1 H), 10.24 (t, J = 5.8 Hz, 1 H). ¹³C NMR (CDCI₃): δ 16.09, 26.95, 29.30, 36.79, 45.1 1 , 45.28, 53.86, 62.47, 75.93, 103.87 (t, J = 25.4 Hz), 1 1 1 .21 (dd, J = 21 .0, 3.4 Hz), 1 17.32, 130.58 (dd, J = 9.3, 5.8 Hz), 133.40, 143.54, 155.34, 163.16, 163.25, 163.35, 172.88.

Example 19:

To a suspension of 5 (1 .67 g, 4 mmol) in acetonitrile (20 mL) was added DABCO (23 mg, 5 mol%) and TCCA (0.62 g, 2.52 mmol). The mixture was stirred 18 h at 40 °C protected from light and then quenched with a mixture of DMSO (0.48 mL) and water (0.12 mL). The insoluble cyanuric acid was removed by filtration and washed with acetonitrile (5 mL). The filtrate was evaporated under reduced pressure to give viscous oil that was crystallized from a mixture of methanol (6 mL) and water (3 mL), by slowly cooling the solution from 60 °C to room

temperature. The product 6 was filtered, washed with cold methanol (5 mL) and dried to give an off-white powder (1.07 g, 61 %).

¹H NMR (CDCI₃): δ 1.30 (d, J = 7.0 Hz, 3H), 1 .49 (dd, J = 14.0, 2.2 Hz, 1 H), 2.14 (ddd, J = 14.6, 1 1.1 , 6.4 Hz, 1 H), 3.89-3.95 (m, 2H), 4.09-4.15 (m, 1 H), 4.26 (dd, J = 13.4, 3.8 Hz, 1 H), 4.55 (d, J = 5.8 Hz, 2H), 4.89-4.98 (m, 1 H), 5.18 (dd, J = 6.2, 3.8 Hz, 1 H), 6.68-6.79 (m, 2H), 7.23-7.31 (m, 1 H), 8.41 (s, 1 H), 10.24 (t, J = 5.8 Hz, 1 H). ¹³C NMR (CDCI₃): δ 16.09, 26.95, 29.30, 36.79, 45.1 1 , 45.28, 53.86, 62.47, 75.93, 103.87 (t, J = 25.4 Hz), 1 1 1 .21 (dd, J = 21.0, 3.4 Hz), 1 17.32, 130.58 (dd, J = 9.3, 5.8 Hz), 133.40, 143.54, 155.34, 163.16, 163.25, 163.35, 172.88.

Example 20:

To a suspension of 6 (0.44 g) in anhydrous methanol (1 mL) was added a 25% methanolic solution of sodium methylate (1 .14 mL) and the mixture stirred for 4 h at 40 °C. The reaction was quenched with acetic acid (0.4 mL), diluted with water (8 mL), extracted with 2-methyltetrahydrofuran (12 mL), the extract washed with 1 M NaOH(aq) (8 mL), water (8 mL) and evaporated under reduced pressure. To the oily residue was added methanol (8 mL) and evaporated under reduced pressure to give 27 as a white solid (0.38 g, 88%).

Example 21 :

The suspension of (4R, 12aS)-7-chloro-N-(2,4-difluorobenzyl)-4-methyl-6,8-dioxo-3,4,6,8,12, 12a-hexahydro-2H-pyrido[1 ‘,2’:4,5]pyrazino[2, 1 -b][1 ,3]oxazine-9-carboxamide (6, 0.44 g) and solid sodium hydroxide (0.20 g) in absolute ethanol (2 mL) was stirred at room temperature for 24 h. The reaction was quenched with 2M H₂S0₄ (1 .18 mL) and left stirring for 2 h at room temperature. The reaction mixture was filtered through fitted funnel rinsing with water (2 x 2 mL). The obtained white precipitate (0.38 g) was suspended in THF-water (1 :1 , 4.5 mL) and stirred at room temperature for ca. 2 h. The reaction mixture was filtered through fitted funnel rinsing with water (2 ^χ 1 mL) and dried in vacuo at 40°C to afford pure dolutegravir as a white solid (0.33 g, HPLC purity: 99.38%).

¹H NMR (DMSO-d₆): δ 12.51 (s, 1 H), 10.36 (t, J=5.9 Hz, 1 H), 8.50 (s, 1 H), 7.41-7.36 (m, 1 H), 7.26-7.21 (m, 1 H), 7.07-7.03 (m, 1 H), 5.45 (dd, J=5.4, 4.3 Hz, 1 H), 4.81 -4.76 (m, 1 H), 4.59-4.53 (m, 3H), 4.36 (dd, J=13.8, 5.8 Hz, 1 H), 4.05-4.00 (m, 1 H), 3.91-3.88 (m, 1 H), 2.05-1 .97 (m, 1 H), 1.55-1.52 (m, 1 H), 1 .33 (d, J=7.1 Hz, 3H). ¹³C NMR (DMSO-d₆): δ 170.27, 163.68, 162.29, 161 .78 (dd), 159.82 (dd), 154.61 , 140.64, 130.74 (d), 130.67 (d), 122.37 (d), 1 16.73, 1 15.38, 1 1 1 .33 (d), 103.80 (t), 62.01 , 51 .16, 44.69, 35.74, 29.13, 15.21.

Example 22:

A suspension of dolutegravir (0.31 g) in methanol (4 mL) was cooled to 0 °C.25% Solution of sodium methoxide in methanol was added to the mixture and the resulting suspension was stirred at 0 °C for 2 h, then at room temperature for 23 h. The reaction mixture was then filtered through fitted funnel rinsing with methanol (3 x 10 mL). The white precipitate was dried overnight at room temperature to afford pure dolutegravir sodium as a white solid (0.26 g, HPLC purity: 99.84%).

¹H NMR (DMSO-d₆): δ 10.70 (t, J=5.8, 1H), 7.89 (s, 1H), 7.37-7.30 (m, 1H), 7.23-7.19 (m, 1H), 7.04-7.01 (m, 1H), 5.17 (m, 1H), 4.81 (t, J=6.4Hz, 1H), 4.51 (d, J=5.5Hz, 2H), 4.32-4.29 (m, 1H), 4.16 (dd, J=14.1, 4.8 Hz, 1H), 3.99-3.94 (m, 1H), 3.82-3.80 (m, 1H), 1.89-1.84 (m, 1H), 1.38 (d, J=12.9 Hz, 1H), 1.24 (d, J=7.0Hz, 3H).¹³C NMR (DMSO-d₆): δ 177.93, 167.12, 166.08, 161.59 (dd), 161.13, 159.63 (dd), 134.26, 130.44 (d), 130.38 (d), 122.90 (d), 114.95, 111.23 (d), 108.78, 103.64 (t), 75.59, 61.95, 53.11, 43.01, 35.32, 29.22, 15.30.

Example 23:

The suspension of 6 (0.44 g) and solid sodium hydroxide (0.20 g) in absolute ethanol (2 mL) was stirred at room temperature for 24 h. The reaction was diluted with absolute ethanol (10 mL) and left stirring for ca. 30 min at room temperature. The reaction mixture was filtered through fitted funnel rinsing with absolute ethanol (3 x 10 mL) and dried in vacuo at room temperature to afford dolutegravir sodium as a pale yellow solid (0.43 g, HPLC purity: 98.80%). ¹H NMR (DMSO-d₆): δ 10.70 (t, J = 5.8 Hz, 1H), 7.89 (s, 1H), 7.37-7.30 (m, 1H), 7.23-7.19 (m, 1H), 7.04-7.01 (m, 1H), 5.17 (m, 1H), 4.81 (t, J = 6.4 Hz, 1H), 4.51 (d, J = 5.5 Hz, 2H), 4.32-4.29 (m, 1H), 4.16 (dd, J= 14.1, 4.8 Hz, 1H), 3.99-3.94 (m, 1H), 3.82-3.80 (m, 1H), 1.89-1.84 (m, 1H), 1.38 (d, J = 12.9 Hz, 1H), 1.24 (d, J = 7.0 Hz, 3H).¹³C NMR (DMSO-d₆): δ 177.93, 167.12, 166.08, 161.59 (dd), 161.13, 159.63 (dd), 134.26, 130.44 (d), 130.38 (d), 122.90 (d), 114.95, 111.23 (d), 108.78, 103.64 (t), 75.59, 61.95, 53.11, 43.01, 35.32, 29.22, 15.30.

Example 24:

The suspension of (4R,12aS)-N-(2,4-difluorobenzyl)-7-methoxy-4-methyl-6,8-dioxo-3,4,6,8,12, 12a-hexahydro-2H-pyrido[1′,2′:4,5]pyrazino[2,1-6][1,3]oxazine-9-carboxamide (27, 0.43 g) and solid sodium hydroxide (0.20 g) in absolute ethanol (2.5 mL) was stirred at room temperature for ca.24 h. The reaction was diluted with mixture of water/ethanol (5 mL, 1:1) and left stirring for ca. 1.5 h at room temperature. The reaction mixture was filtered through fitted funnel rinsing with mixture of water/ethanol (3 x 5 mL, 1:1) and dried in vacuo at room temperature to afford 15 as a pale yellow solid (0.41 g, HPLC purity: 98.87%).

¹H NMR (DMSO-de): δ 10.70 (t, J = 5.8 Hz, 1H), 7.89 (s, 1H), 7.37-7.30 (m, 1H), 7.23-7.19 (m, 1H), 7.04-7.01 (m, 1H), 5.17 (m, 1H), 4.81 (t, J = 6.4 Hz, 1H), 4.51 (d, J = 5.5 Hz, 2H), 4.32-4.29 (m, 1H), 4.16 (dd, J = 14.1, 4.8 Hz, 1H), 3.99-3.94 (m, 1H), 3.82-3.80 (m, 1H), 1.89-1.84 (m, 1H), 1.38 (d, J = 12.9 Hz, 1H), 1.24 (d, J = 7.0 Hz, 3H).¹³C NMR (DMSO-d₆): δ 177.93, 167.12, 166.08, 161.59 (dd), 161.13, 159.63 (dd), 134.26, 130.44 (d), 130.38 (d), 122.90 (d), 114.95, 111.23 (d), 108.78, 103.64 (t), 75.59, 61.95, 53.11, 43.01, 35.32, 29.22, 15.30.

Example 25:

The suspension of {4R, 12aS)-7-chloro-4-methyl-6,8-dioxo-3,4, 6,8, 12,12a-hexahydro-2H-pyrido[1′,2′:4,5]pyrazino[2,1-6][1,3]oxazine-9-carboxylic acid (7, 0.31 g) and solid sodium hydroxide (0.20 g) in absolute ethanol (2.5 mL) was stirred at 50 °C for 3 days. The reaction was quenched with 2M H₂S0₄ (1.2 mL) and left stirring for 7 h at room temperature. The reaction mixture was filtered through fitted funnel rinsing with water (3×5 mL) and ethanol (5 mL) dried in vacuo at 40°C to afford 28 as a pale yellow solid (0.17 g).

¹H NMR (DMSO-d₆): δ 15.37 (s, 1H), 12.76 (s, 1H), 8.66 (s, 1H), 5.51-5.49 (m, 1H), 4.80-4.78 (m, 1H), 4.65 (dd, J=13.8, 3.7 Hz, 1H), 4.43 (dd, J=13.8, 5.9 Hz, 1H), 4.05 (t, J^^.b Hz, 1H), 3.91 (dd, J=11.4, 3.1 Hz, 1H), 2.07-2.00 (m, 1H), 1.56 (d, J=13.8 Hz, 1H), 1.34 (d, J=7.0 Hz, 3H).¹³C NMR (DMSO-de): δ 172.21, 165.39, 161.73, 153.61, 141.11, 118.66, 112.99, 75.95, 62.03, 51.50, 44.90, 29.08, 15.18.

Example 26:

The suspension of (4R,12aS)-N-(2,4-difluorobenzyl)-7-methoxy-4-methyl-6,8-dioxo-3,4,6,8, 12, 12a-hexahydro-2H-pyrido[1 ‘,2’:4,5]pyrazino[2, 1 ,3]oxazine-9-carboxamide (27, 0.88 g) and solid sodium hydroxide (0.24 g) in absolute ethanol (20 mL) was stirred at 30 °C for 1.5 h. The reaction was quenched with 2M H₂S0₄ (1 .5 mL) and left stirring for 3 hours at room temperature. The reaction mixture was filtered through fritted funnel and rinsed with water (3 x 2 mL) and ethanol (4 mL), and dried in vacuo at 40 °C to afford O-ethyl dolutegravir (29) as a pale yellow solid (0.25 g). The filtrate was extracted with ethyl acetate (3 x 5 mL). The combined organic layers were dried over MgS0₄, filtered and concentrated, then dried in vacuo at 40 °C to afford more 29 as a pale yellow solid (0.27 g).

¹H NMR (CDCI₃): δ 10.37 (t, J = 5.8 Hz, 1 H), 8.36 (s, 1 H), 7.37-7.32 (m, 1 H), 6.83-6.77 (m, 2H), 5.19 (dd, J = 5.9, 3.8 Hz, 1 H), 5.04-4.98 (m, 1 H), 4.61 (d, J = 6Hz, 2H), 4.26-4.22 (m, 3H), 4.1 1 (dd, J = 13.4, 5.9 Hz, 1 H), 3.97 (t, J = 2.4 Hz, 1 H), 3.96 (d, J = 2.4 Hz, 1 H), 2.21-2.14 (m, 1 H), 1.51 (dq, J = 14.0, 2.3 Hz, 1 H), 1 .47 (t, J = 7.0 Hz, 3H), 1 .35 (d, J = 7.1 Hz, 3H).

¹³C NMR (CDCI₃): δ 174.78, 164.17, 162.49 (dd), 160.51 (dd), 155.72, 154.08, 142.32, 130.60 (dd), 129.33, 121 .51 (dd), 1 18.67, 1 1 1 .23 (dd), 103.78 (t), 76.15, 69.74, 62.58, 53.42, 44.58, 36.50 (d), 29.44, 16.04, 15.64.

Example 27:

The suspension of (4R, 12aS)-7-(benzyloxy)-4-methyl-3,4, 12,12a-tetrahydro-2H-pyrido[1 ‘,2’:4,5]pyrazino[2, 1-b][1 ,3]oxazine-6,8-dione (30, 0.68 g, prepared according to prior art) and solid sodium hydroxide (0.40 g) in absolute ethanol (5 mL) was stirred at 50 °C for 14 h. The reaction was quenched with formic acid (0.35 mL), water (2 mL) was added and mixture was left stirring for additional 1 h at room temperature. The reaction mixture was extracted with ethyl acetate (3 x 5 mL) and the combined organic layers concentrated to afford a crude oil. Purification by flash chromatography (eluting with CH₂CI₂/methanol) afforded 32 as an orange solid (0.26 g, 52 %).

The above procedure if done at room temperature in same time period, affords 31 as orange oil (0.24 g, 43 %).

Compound 32: ¹H NMR (DMSO-d₆): δ 7.64 (d, J = 7.4 Hz, 1 H), 6.20 (d, J = 7.3 Hz, 1 H), 5.40 (dd, J = 5.1 , 4.2 Hz, 1 H), 4.83-4.78 (m, 1 H), 4.35 (dd, J = 13.6, 3.9 Hz, 1 H), 4.13 (dd, J = 13.6, 5.4 Hz, 1 H), 4.05-4.00 (m, 1 H), 3.90-3.85 (m, 1 H), 2.03-1.95 (m, 1 H), 1.52 (dd, J = 13.9, 1 .9 Hz, 1 H), 1.33 (d, J = 7.1 Hz, 3H). ¹³C NMR (DMSO-d₆): δ 170.96, 163.01 , 153.48, 137.96, 1 16.83, 1 13.52, 76.18, 62.05, 50.39, 44.53, 29.21 , 15.28.

Compound 31 : ¹H NMR (DMSO-d₆): δ 7.67 (d, J = 7.4 Hz, 1 H), 6.28 (d, J = 7.4 Hz, 1 H), 5.29 (dd, J = 5.4, 3.8 Hz, 1 H), 4.82-4.75 (m, 1 H), 4.32 (dd, J = 13.6, 3.6 Hz, 1 H), 4.10 (dd, J = 13.5, 5.6 Hz, 1 H), 4.03-3.93 (m, 3H), 3.85 (ddd, J = 1 1 .6, 5.0, 2.2 Hz, 1 H), 1.97-1 .89 (m, 1 H), 1 .48 (dd, J = 13.8, 2.1 Hz, 1 H), 1.27 (d, J = 7.1 Hz, 3H), 1.26 (d, J = 7.0 Hz, 3H). ¹³C NMR (DMSO-d₆): δ 174.38, 156.1 1 , 150.82, 139.48, 1 16.39, 1 13.52, 75.92, 67.31 , 61 .80, 51 .36, 44.22, 29.29, 15.76, 15.36.

Exa

The transformation of 6 to dolutegravir with sodium hydroxide in ethanol was monitored for the interconversion of intermediates. The suspension of 6 (0.44 g) and solid sodium hydroxide (0.20 g) in ethanol (3.33 ml.) was stirred at 22 °C. Samples of the reaction mixture were taken after 3, 8 and 24 h for UPLC analysis. After 24 h, the reaction mixture was quenched with 2 M H₂S0₄ (5 ml_), and left stirring at room temperature. The reaction mixture was filtered through fritted funnel, the product rinsed with water (30 ml.) and dried in vacuo at 50 °C overnight to afford dolutegravir as a white solid (0.27 g, 64 %).

The results of reaction monitoring:

Time UPLC analysis (area%)

Entry

(h) compound 6 compound 29 dolutegravir

1 3 h 37.50 20.63 39.99

2 8 h 0.78 15.46 80.32

3 24h 0.31 8.56 88.21

Example 29:

The effect of added water and reaction temperature was evaluated by monitoring 4 reactions in parallel. To the suspensions of 27 (0.86 g) in MeOH were added solid sodium hydroxide (0.40 g) or aqueous solution of NaOH (5 M, 2 ml.) (see Table below). The reactions were stirred in parallel at 50 °C or 22 °C. Samples were taken in timely intervals for UPLC analysis.

The results of reaction monitoring demethylation of 27 in MeOH:

Example 30:

The effect of added water and reaction temperature was evaluated by monitoring 4 reactions in parallel. To the suspensions of 6 (0.88 g) in EtOH were added solid sodium hydroxide (0.40 g) or aqueous solution of NaOH (5 M, 2 mL) (see Table below). The reactions were stirred in parallel at 50 °C or 22 °C. Samples were taken in timely intervals for UPLC analysis.

The results of reaction monitoring of the transformations of 6 in ethanol with NaOH:

dol. = dolutegravir

Exa

The effect of added water and reaction temperature was evaluated by monitoring 4 reactions in parallel. To the suspensions of 27 (0.88 g) in EtOH were added solid sodium hydroxide (0.40 g) or aqueous solution of NaOH (5 M, 2ml_) (see Table below). The reactions were stirred in parallel at 50 °C or 22 °C. Samples were taken in timely intervals for UPLC analysis.

The results of reaction monitoring of the transformations of 27 in ethanol with NaOH:

dol. = dolutegravir

Example 32:

Compound 3 (30 g, 1 10 mmol; assay 99%) was suspended in acetonitrile (450 mL), acetic acid (73 mL) and methanesulfonic acid (25 mL) were added. The reaction mixture was stirred 4 h at 70 °C. The clear red solution was cooled to 25 °C. Triethylamine (77 mL) and (S)-2-aminopropanol (17 mL) were added and the mixture was stirred at reflux temperature for 20 h. The reaction mixture was cooled to 25 °C and the insoluble product filtered, washed with 1 M HCI(aq) (60 mL), water (3 * 60 mL) and dried to give 4c (19.49 g, 67%): mp = 313-315 °C; ¹H NMR (DMSO-d₆): δ 1.31 (d, J = 6.3 Hz, 3H), 3.65 (dd, J = 8.6, 6.8 Hz, 1 H), 4.13 (dd, J = 1 1.7, 10.3 Hz, 1 H), 4.28 (m, 1 H), 4.39 (dd, J = 8.6, 6.8 Hz, 1 H), 4.92 (dd, J = 12.3, 4.2 Hz, 1 H), 5.45 (dd, J = 10.2, 4.1 Hz, 1 H), 7.16 (s, 1 H), 8.84 (s, 1 H), 15.74 (s, 1 H); ¹³C NMR (DMSO-d₆) 16.5, 51.6, 52.9, 72.4, 81.6, 1 15.8, 1 18.1 , 141.5, 147.6, 153.4, 165.3, 179.0.

Example 33

Compound 4c (2.78 g) was suspended in dimethylformamide (40 mL), cooled to 0 °C, then triethylamine (3.52 mL) was added, followed by ethyl chloroformate (1 .31 mL). After 10 min there was added 2,4-difluorobenzylamine (1 .57 mL). The mixture was then stirred at 25 °C for 1 h. Water (150 mL) was added and the mixture extracted with dichloromethane (50 mL). The organic phase was separated, washed with water (2 ^χ 50 mL), dried over sodium sulfate and evaporated under reduced pressure. The residue (4.31 g) was treated with boiling 2-propanol (40 mL), the suspension cooled, the product filtered and dried to give the product 5c as a white powder (2.70 g, 69%): 99.80 area% by HPLC at 258 nm; mp = 222-223 °C; MS (ESI) m/z = 390 [MH]⁺; ¹H NMR (DMSO-d₆): δ 1 .30 (d, J = 6.3 Hz, 3H), 3.63 (dd, J = 8.6, 6.8 Hz, 1 H), 4.02 (m, 1 H), 4.26 (m, 1 H), 4.37 (dd, J = 8.6, 6.8 Hz, 1 H), 4.53 (d, J = 6.0 Hz, 2H), 4.84 (dd, J = 12.2, 4.2 Hz, 1 H), 5.40 (dd, J = 12.2, 4.2 Hz, 1 H), 6.91 (s, 1 H), 7.05 (m, 1 H), 7.24 (m, 1 H), 7.38 (m, 1 H), 8.62 (s, 1 H), 10.43 (t, J = 6.0 Hz, 1 H).

To a suspension of 5c (2.70 g, 6.9 mmol) in acetonitrile (32 mL) was added DABCO (39 mg, 5 mol%) and TCCA (1.01 g, 4.3 mmol). The mixture was stirred 20 h at 40 °C protected from light and then quenched with a mixture of DMSO (0.81 mL) and water (0.20 mL). The insoluble cyanuric acid was removed by filtration and washed with acetonitrile (10 mL). The filtrate was evaporated under reduced pressure to give viscous oil that was crystallized from a mixture of methanol (10 mL) and water (5 mL), by slowly cooling the solution from 60 °C to room temperature. The product 6c was filtered, washed with cold methanol (8 mL) and dried to give an off-white powder (1 .20 g, 41 %): mp = 225-227 °C; MS (ESI) m/z = 424 [MH]⁺; ¹H NMR

(DMSO-d₆): δ 1.28 (d, J = 6.3 Hz, 3H), 3.65 (dd, J = 8.6, 6.9 Hz, 1 H), 4.09 (m, 1 H), 4.26 (m, 1 H), 4.35 (dd, J = 8.6, 6.6 Hz, 1 H), 4.54 (d, J = 5.9 Hz, 2H), 4.85 (dd, J = 12.3, 3.8 Hz, 1 H), 5.42 (dd, J = 10.1 , 3.8 Hz, 1 H), 7.06 (m, 1 H), 7.24 (m, 1 H), 7.40 (m, 1 H), 8.67 (s, 1 H), 10.24 (t, J = 6.0 Hz, 1 H).

Example 35

cabotegravir

The suspension of 6c (1.00 g, 2.4 mmol) and sodium hydroxide (0.57 g, 14.2 mmol) in absolute ethanol (7 mL) was stirred at 40 °C for 16 h. The reaction was quenched with 0.5M H₂S0₄ (15 mL), extracted with dichloromethane (20 mL), the extract washed with water (20 mL) and evaporated under reduced pressure. The residue was triturated in MTBE (10 mL), the product filtered, washed with MTBE (10 mL) and dried to give cabotegravir as an off-white solid (0.74 g, 77%): MS (ESI) m/z = 405 [MH]⁺.

Lek, a Sandoz company, opens the first production facility in Slovenia for drug substances for innovative medicines at its Mengeš site

Vojmir Urlep, president of Lek Board of Management

Photo for print

////////////Carbotegravir, Dolutegravir, New Patent, WO 2016113372, Lek Pharmaceutical and Chemical Co DD

WO 2016113415, Sandoz, Riociguat, New Patent

STEFINOVIC, Marijan; (AT).
RICHTER, Frank; (AT).
GRIESSER, Ulrich; (AT).
LANGES, Christoph; (AT)

SANDOZ AG [CH/CH]; Lichtstrasse 35 4056 Basel (CH)

WO 2016113415

Novel method for purifying riociguat, useful for treating chronic thromboembolic pulmonary hypertension, pulmonary arterial hypertension, systemic sclerosis and Raynaud’s phenomenon. Also claims novel crystalline solvates of riociguat (eg ethyl acetate or butan-2-one solvate), useful as intermediates in the purification of riociguat. Bayer and licensee Merck have developed and launched riociguat.

The present filing appears to be the first filing from Sandoz on riociguat; however see WO2015095515, assigned to Novartis, parent company of Sandoz, claiming an ophthalmic composition comprising a soluble guanylate cyclase activator (eg riociguat).

Riociguat (BAY 63-2521 ), having the chemical name N-[4,6-Diamino-2-[1-(2-fluorobenzyl)-1 H-pyrazolo[3,4-b]pyridin-3-yl]pyrimidin-5-yl]-N-methylcarbamic acid methyl ester, or sometimes also called or also sometimes called Methyl-(4,6-diamino-2-(1-(2-fluorobenzyl)-1 H-pyrazolo[3, 4-b]pyridin-3-yl)-5-pyrimidinyl)(methyl)carbamate is a stimulator of the soluble guanylate cyclase.

Riociguat has been approved for the treatment of inoperable, or persistent, recurrent chronic thromboembolic pulmonary hypertension (CTEPH) after surgery in adult patients and for the treatment of pulmonary arterial hypertension and is in development for the treatment of systemic sclerosis and Raynaud’s phenomenon.

(I)

The preparation of the compound of formula (I) and its purification are known. According to the experimental procedure of Example 8 of WO 03/095451 (comparable description in Chem. Med. Chem 2009, 4, 853-865), iodomethane is used as an alkylating agent in a late step and the purification of the crude riociguat either comprised preparatory HPLC steps or several steps of extracting, precipitating, suspending, washing, redissolving and reprecipitating riociguat, resulting in a long and tedious workup procedure with moderate yield.

In WO 201 1/064171 a potential genotoxic azo compound of formula III is used as a key intermediate, which under catalytic hydrogenation forms a compound of formula VIII.

The compound of formula VIII is further reacted with a methyl chloroformate or with a dimethyl carbonate derivative to form a compound of formula VI. The compound of formula VI is then methylated to form crude riociguat of formula (I).

Crude riociguat of formula (I) is then purified by a process comprising the intermediate isolation of a riociguat DMSO solvate of formula (II).

For the pharmaceutical use of riociguat, the solvent DMSO has to be removed. To that end, the compound of formula (II) is boiled in pharmaceutically acceptable solvents such as ketones, esters, ethers or alcohols. However, the riociguat obtained in this manner contains detectable amounts of DMSO.

These processes for the preparation of riociguat and their laborious purification protocols have a number of disadvantages which are unfavorable for industrial realization on a large scale.

On the one hand, the purification process according to WO 03/095451 require the repeated isolation of solid intermediates or preparatory HPLC, which ultimately results in a reduced yield of pure riociguat of formula (I) of pharmaceutical grade. Yet, traces of compound of formula (III) remain.

It is therefore one of the objects of the present invention to provide a process for the preparation of pure riociguat – compound of the formula (I) – which yields riociguat free from any genotoxic impurity and/or mutagenic impurity.

On the other hand, the process for the preparation of riociguat described in WO 201 1/064171 has a different serious drawback. It comprises the use of a DMSO solvate.

DMSO is an active pharmaceutical ingredient by itself. It is used as an active pharmaceutical ingredient in the treatment of interstitial cystitis. DMSO removal is difficult to achieve by the published processes. It is thus a further object of the invention to provide riociguat essentially free from DMSO and suitable for pharmaceutical use.

WO 2014/128109 discloses forms of riociguat, such as polymorphs and solvates, and describes a ¼ ethyl acetate solvate of riociguat in example 6. The X-ray powder

diffractogram in Tab.3 and figure 4 comprises reflexes at °2Theta positions of 9.1 and 25.6.

Thus, there is a need in the art for a process, which allows the preparation of pure riociguat free from any genotoxic impurity and/or mutagenic impurity which at the same time does not comprise residual DMSO.

Surprisingly, we have now identified a process for the purification of crude riociguat which yields riociguat which is essentially free from genotoxic impurities and DMSO. In particular, this novel process differs from the processes known to date in that the isolation of intermediates prior to the formation of riociguat is not required. This process allows to overcome the disadvantages of the processes known to date and to obtain riociguat in high yield and high purity and pharmaceutical acceptable quality essentially free of genotoxic impurities.

Examples

Preparative example

Preparation of crude riociguat

Riociguat was prepared as disclosed in example 7 of WO 201 1/064171 and had a chemical purity of 91.7% by the area of the riociguat peak in the HPLC-UV elution profile.

Comparative Example 1

Preparation of DMSO solvate

An amount of 4.505 g (0.0107 moles) of crude riociguat was dissolved in 8 ml DMSO at 100 °C. The obtained brownish, turbid solution was then cooled to 75 °C within 16 minutes. After that 55 ml of ethylacetate were added and the mixture was cooled to 25 °C (30 minutes). After 22 h the obtained precipiate was filtered off, washed with 14 ml EtOAc and dried for 4 hours at 50 °C at reduced pressure (50 mbar). The precipitate was analysed with XRPD, confirming that riociguat DMSO was obtained. The product was also analyzed by HPLC-UV-MS. Purity was calculated based on UV detection at 254nm. The so obtained riociguat DMSO solvate was 91 .92% pure.

Comparative Example 2

Preparation of riociguat form I from riociguat DMSO solvate

The entire product prepared in comparative example 1 (4.283 g = 0.009 moles) was reflux heated in 77 ml of ethylacetate at 78 °C for 1 h and then cooled to 25 °C. The white solid was filtered off with suction, washed with a total of 18 ml of ethyl acetate and dried at 50 °C under reduced pressure (50 mbar) for 5 hours. The dried product was then analyzed by XRPD, confirming identity of riociguat form I unequivocally.

Yield (dry): 3.224 g (0.0076 moles) = 75% for comparative example 2 and 72% overall (C.ex. 1 and 2). Total organic volatile impurity is higher than 1000 ppm and total DMSO content is higher than 100 ppm.

Example 1 ; Preparation of Riociguat ethylacetate solvate

Crude Riociguat (500 mg; Form I; 91 .7% percentage area purity) was dissolved in 2 ml DMF and heated to 100 °C to obtain a slightly turbid solution. After filtration through a 0.44 micron filter, 20 ml EtOAc were added to the hot solution (water bath 70°C) and allowed to stand. The temperature was slowly decreased to ambient temperature. Crystallization started after

10min. The yellowish, fine powder was filtered off and dried at ambient conditions. The PXRD indicated the formation of a new ethylacetate solvate. Yield 71 %, 97.8% purity.

Example 2; Preparation of the Methyl ethyl ketone (butan-2-one) solvate of Riociguat.

Crude Riociguat (500 mg; Form I; 91 .7% percentage area purity) was dissolved in 2 ml DMF at 100 °C to obtain a clear solution. After filtration through a 0.44 micron filter, 20 ml MEK were added. The hot solution (water bath 70 °C) was allowed stand. The temperature was then slowly decreased to ambient temperature. After 30 minutes yellowish, square-shaped crystals appeared, which were analyzed. Analysis confirmed that they were a new crystalline MEK-solvate. Yield 43%, 97.2% purity.

Example 3 ; Conversion of Solvated forms to Form I

Both the solvates from examples 1 and 2 can be converted to riociguat Form I by heating the material to 150°C under vacuum for an appropriate amount of time.

Example 4; Direct preparation of riociguat form I from crude riociguat using DMF-Acetone Crude Riociguat (200 mg; Form I; 91 .7% percentage area purity) was dissolved in 1.0 ml DMF at 100 °C to obtain a clear solution. After filtration through a 0.44 micron filter, 5 ml acetone was added. The hot solution (water bath 70 °C) was allowed to stand. Crystallisation occurred while the temperature was slowly decreased to ambient temperature. After 24 hours the precipitate was filtered off and dried at ambient conditions to obtain form I. Yield 78% ; 97.6% purity

///////////WO 2016113415, Sandoz, Riociguat, New Patent

Mifamurtide (Mepact)

• MF C₅₉H₁₀₉N₆O₁₉P
• MW 1237.499

Mifamurtide (trade name Mepact, marketed by Takeda) is a drug against osteosarcoma, a kind of bone cancer mainly affecting children and young adults, which is lethal in about a third of cases. The drug was approved in Europe in March 2009.

History

The drug was invented by Ciba-Geigy (now Novartis) in the early 1980s and sold to Jenner Biotherapies in the 1990s. In 2003,IDM Pharma bought the rights and developed it further.^[1] IDM Pharma was acquired by Takeda along with mifamurtide in June 2009.^[2]

Mifamurtide had already been granted orphan drug status by the U.S. Food and Drug Administration (FDA) in 2001, and theEuropean Medicines Agency (EMA) followed in 2004. It was approved in the 27 European Union member states plus Iceland, Liechtenstein, and Norway by a centralized marketing authorization in March 2009. The drug was denied approval by the FDA in 2007.^[3][4] Mifamurtide has been licensed by the EMA since March, 2009.^[5]

Indications

Mifamurtide is indicated for the treatment of high-grade, nonmetastasizing, resectable osteosarcoma following complete surgical removal in children, adolescents, and young adults, aged two to 30 years.^[1][6][7] Osteosarcoma is diagnosed in about 1,000 individuals in Europe and the USA per year, most under the age of 30.^[8] The drug is used in combination with postoperative, multiagent chemotherapy to kill remaining cancer cells and improve a patient’s chance of overall survival.^[6]

In a phase-III clinical trial in about 800 newly diagnosed osteosarcoma patients, mifamurtide was combined with the chemotherapeutic agents doxorubicin and methotrexate, with or without cisplatin and ifosfamide. The mortality could be lowered by 30% versus chemotherapy plus placebo. Six years after the treatment, 78% of patients were still alive. This equals an absolute risk reduction of 8% .^[1]

Adverse effects

In a clinical study, mifamurtide was given to 332 subjects (half of whom were under age of 16) and most side effects were found to be mild to moderate in nature. Most patients experience fewer adverse events with subsequent administration.^[9][10]Common side effects include fever (about 90%), vomiting, fatigue and tachycardia (about 50%), infections, anaemia, anorexia, headache, diarrhoea and constipation(>10%).^[1][11]

Pharmacokinetics

After application of the liposomal infusion, the drug is cleared from the plasma within minutes and is concentrated in lung, liver, spleen, nasopharynx, and thyroid. The terminal half-life is 18 hours. In patients receiving a second treatment after 11–12 weeks, no accumulation effects were observed.^[12]

Pharmacodynamics

Mifamurtide is a fully synthetic derivative of muramyl dipeptide (MDP), the smallest naturally occurring immune stimulatory component of cell walls from Mycobacterium species. It has similar immunostimulatory effects as natural MDP with the advantage of a longer half-life in plasma.

NOD2 is a pattern recognition receptor which is found in several kinds of white blood cells, mainly monocytes and macrophages. It recognises muramyl dipeptide, a component of the cell wall of bacteria. Mifamurtide simulates a bacterial infection by binding to NOD2, activating white cells. This results in an increased production of TNF-α, interleukin 1,interleukin 6, interleukin 8, interleukin 12, and other cytokines, as well as ICAM-1. The activated white cells attack cancer cells, but not, at least in vitro, other cells.^[13]

Interactions

• Theoretical considerations suggest calcineurin inhibitors like ciclosporin and tacrolimus might interact with mifamurtide because of their effect on macrophages.
• High-dose NSAIDs block the mechanism of mifamurtide in vitro.

Consequently, the combination of mifamurtide with these types of drugs is contraindicated. However, mifamurtide can be coadministered with low doses of NSAIDs. No evidence suggests mifamurtide interacts with the studied chemotherapeutics, or with the cytochrome P450 system.^[14]

Chemistry

Mifamurtide is muramyl tripeptide phosphatidylethanolamine (MTP-PE), a synthetic analogue of muramyl dipeptide. The side chains of the molecule give it a longer elimination half-life than the natural substance. The substance is applied encapsulated into liposomes (L-MTP-PE). Being a phospholipid, it accumulates in the lipid bilayer of the liposomes in the infusion.^[15]

Synthesis

One method of synthesis (shown first) is based on N,N’-dicyclohexylcarbodiimide (DCC) assisted esterification of N-acetylmuramyl-L-alanyl-D–isoglutaminyl–L-alanine with N-hydroxysuccinimide, followed by a condensation with 2-aminoethyl-2,3-dipalmitoylglycerylphosphoric acid in triethylamine (Et₃N).^[16] A different approach (shown second) uses N-acetylmuramyl-L-alanyl-D-isoglutamine, hydroxysuccinimide and alanyl-2-aminoethyl-2,3-dipalmitoylglycerylphosphoric acid;^[17] that is, the alanine is introduced in the second step instead of the first.

Synthesis

Mifamurtide is an anticancer agent for the treatment of osteosarcoma, the most common primary malignancy of bone tissue mainly affecting children and adolescents.10

The drug was invented by Ciba-Geigy (now Novartis) in the early 1980s and the agent was subsequently licensed to Jenner Biotherapies in the 1990s.

IDM Pharma bought the rights to the drug from Jenner in April 2003.78 In March 2009, mifamurtide was approved in the 27 European Union member states plus Iceland, Liechtenstein and Norway via a centralized marketing authorization.

After the approval, IDM Pharma was acquired by Takeda, which began launching mifamurtide, as Mepact, in February 2010.

Mifamurtide, a fully synthetic lipophilic derivative of muramyl dipeptide (MDP), is muramyl tripeptide phosphatidylethanolamine (MTP-PE), which is formulated as a liposomal infusion.79 Being a phospholipid, mifamurtide accumulates in the lipid bilayer of the liposomes upon infusion.

After application of the liposomal infusion, the drug is cleared from the plasma within minutes. However, it is concentrated in lung, liver, spleen, nasopharynx and thyroid, and the terminal half-life is 18 h, which is longer than the natural substance.

Two synthetic routes have been reported,80,81 and Scheme 16 describes the more processamenable route.

Commercially available 1,2-dipalmitoyl-sn-glycero- 3-phosphoethanolamine (110) was coupled with N-Boc-L-alanine (111) by means of N-hydroxysuccinimide (112), DCC in DMF to give amide 113, which was followed by hydrogenolysis of the CBZ group to give the corresponding L-alanyl-phosphoric acid 114.

Next, commercially available N-acetylmuramoyl-L-alanyl-Disoglutamine (115) was subjected to hydroxybenzotriazole (HOBT) and DIC in DMF to provide the corresponding succinimide ester 116 which was condensed with compound 114 to provide mifamurtide (IX).

No yields were provided for these transformations.

79. Prous, J. R.; Castaner, J. Drugs Future 1989, 14, 220.
80. Baschang, G.; Tarcsay, L.; Hartmann, A.; Stanek, J. EP 0027258 A1, 1980.
81. Brundish, D. E.; Wade, R. J. Labelled Compd. Radiopharm. 1985, 22, 29.

PATENT

https://www.google.com/patents/CN103408635A?cl=en

mifamurtide, the English called mifamurtide, formula C59Hltl9N6O19P, primarily for the treatment of non-metastatic

Resectable osteosarcoma (a rare but the main cause of death for children and young people osteoma), having the formula as follows:

mifamurtide by certain stimuli such as macrophages and other white blood cells to kill tumor cells. Currently, mifamurtide listed injections into spherical liposome vesicles are muramyl tripeptide (MTP). This lipid trigger macrophages to consume mifamurtide. Once consumed mifamurtide, MTP-stimulated macrophages, in particular we will look for tumors in the liver, spleen and lung macrophages and kill it.

 mifamurtide injection approved for marketing based on the results of phase III clinical study. Taiwan’s National Cancer Institute Cooperative Group (NCI) established by the Children’s Oncology Group (COG) study, complete treatment of this product in patients with osteosarcoma largest research project in the book of about 800 cases. Evaluation of mifamurtide and 3-4 adjuvant chemotherapy (cis molybdenum, doxorubicin, methotrexate, cyclophosphamide with or the same as) the results of combination therapy. Studies have shown that mifamurtide used in combination with chemotherapy can reduce the mortality rate of about 30%, 78% of treated patients survived more than six years.

Shortcomings disclosed the full liquid phase synthesis technology route mifamurtide, but all-liquid phase synthesis: [0006] Currently, mifamurtide universal rely wholly liquid phase synthesis, relevant literature (220 Drugs Futl989, 14, (3)) that the synthesis requires intermediate purification steps cumbersome, time-consuming, and the total yield of the whole liquid phase synthesis is less than 30%, which has been the main factors affecting the productivity of mifamurtide

A method for logging meter synthetic peptide, characterized in that it comprises the following steps: Step 1, under the effect of coupling agent, an amino group, and Fmoc-D-Glu on the amino resin (OPG) -OH main chain carboxyl acylation, a compound of formula I; Step 2, Fmoc removal of the protecting group the compound of formula I, under the effect of coupling with Fmoc-L-Ala-OH acylation, a compound of formula 2; step 3, Fmoc removal of the protecting group the compound of formula 2, in the role of a coupling agent, with a compound of formula 3 for acylation, a compound of formula 4; step 4, PG protecting group removing compound of formula 4, the coupling the role of agent, and HL-Ala-OPG acylation, a compound of formula 5; Step 5, PG protecting group removal compound of formula 5, under the effect of coupling agent, and an amino acid performed on brain phospholipids reaction of a compound of formula 6, and then the resin was added Lysates deaminated compound of formula 7; Step 6, the compound of formula 7 to obtain the removal of benzyl mifamurtide;

Wherein Fmoc is the amino protecting group; wherein PG is a carboxy-protecting group for Allyl or Dmab; Resin as the amino resin.

Example: Synthesis of mifamurtide crude peptide

 Example 11 to give the formula hydrogenolysis at atmospheric pressure to 16 hours Example 7 was added to 7.42 g compound 250ml single neck flask, dried 150ml of methanol was added to dissolve 0.4 g of 10% palladium on carbon.Completion of the reaction, palladium-carbon was filtered off, the filtrate was concentrated by rotary evaporation to 65ml, is mifamurtide crude peptide solution. Mifamurtide synthetic crude peptide: 15 [0173] Example

 Example 12 to give the formula hydrogenolysis at atmospheric pressure to 16 hours Example 7 was added to 4.21 g compound 150ml single neck flask, dried 85ml of methanol was added to dissolve 0.2 g of 10% palladium on carbon.Completion of the reaction, palladium-carbon was filtered off, the filtrate was concentrated by rotary evaporation to 37ml, is mifamurtide crude peptide solution.

16 [0175] Example 2: Preparation of mifamurtide

 The embodiment 14 of crude peptide solution obtained in Example 65ml, IOOOml round bottom flask was added, under magnetic stirring, 650ml of anhydrous diethyl ether was added dropwise. Upon completion, at room temperature for crystallization. After filtration and drying the filter cake, the filter cake was again dissolved in 65ml of methanol. This methanol solution was added IOOOml round bottom flask, under magnetic stirring, 650ml of anhydrous diethyl ether was added dropwise. Upon completion, at room temperature for crystallization. Filtered cake was dried in vacuo to give mifamurtide 5.62g, yield 86.5%, purity 99.4%, total yield 74.5%

Preparation of mifamurtide of: 17 Example

 The embodiment of the crude peptide solution obtained in Example 15, 37ml, 500ml round bottom flask was added, under magnetic stirring, 370ml of anhydrous diethyl ether was added dropwise. Upon completion, at room temperature for crystallization. After filtration and drying the filter cake, the filter cake was again dissolved in 37ml of methanol. This solution was added to methanol 500ml round bottom flask, under magnetic stirring, 370ml of anhydrous diethyl ether was added dropwise. Upon completion, at room temperature for crystallization. Filtered, the filter cake was dried under vacuum to give · mifamurtide 3.16g, yield 85.8%, purity 99.5%, 72.2% overall yield.

References

Mifamurtide

Systematic (IUPAC) name
2-[(N-{(2R)-[(2-acetamido-2,3-dideoxy-D-glucopyranos-3-yl)oxy]-propanoyl}-L-alanyl-D-isoglutaminyl-L-alanyl)amino]ethyl (2R)-2,3-bis(hexadecanoyloxy)propyl hydrogen phosphate
Clinical data
License data	EU EMA: Mepact
Pregnancy category	not investigated
Routes of administration	intravenous liposomal infusion over one hour
Legal status
Legal status	℞ (Prescription only)
Pharmacokinetic data
Bioavailability	N/A
Biological half-life	minutes (in plasma) 18 hrs (terminal)
Identifiers
CAS Number	83461-56-7  838853-48-8 (mifamurtide sodium · xH2O)
ATC code	L03AX15 (WHO)
PubChem	CID 11672602
ChemSpider	9847332
UNII	EQD2NNX741
KEGG	D06619
Chemical data
Formula	C59H109N6O19P
Molar mass	1237.499 g/mol

//////////83461-56-7,  838853-48-8,  CGP-19835,  Mepact,  MFCD09954133,  Mifamurtide,  mifamurtide sodium,  MTP-cephalin,  Mtp-PE,  Muramyl tripeptide, phosphatidylethanolamine,  PEPTIDE,  мифамуртид,  ميفامورتيد,  米法莫肽

CCCCCCCCCCCCCCCC(=O)OCC(COP(O)(=O)OCCNC(=O)[C@H](C)NC(=O)CC[C@@H](NC(=O)[C@H](C)NC(=O)[C@@H](C)O[C@H]1C(O)[C@@H](CO)O[C@@H](O)[C@@H]1NC(C)=O)C(N)=O)OC(=O)CCCCCCCCCCCCCCC

Delamanid

デラマニド

MKT as Deltyba^® by Otsuka Pharmaceutical

http://www.ama-assn.org/resources/doc/usan/delamanid.pdf

(2R)-2-Methyl-6-nitro-2-[(4-{4-[4-(trifluoromethoxy)phenoxy]-1-piperidinyl}phenoxy)methyl]-2,3-dihydroimidazo[2,1-b][1,3]oxazole

2(R)-Methyl-6-nitro-2-[4-[4-[4-(trifluoromethoxy)phenoxy]piperidin-1-yl]phenoxymethyl]-2,3-dihydroimidazo[2,1-b]oxazole

(R) -2-methyl-6-nitro-2- { 4- [4- (4- trifluoromethoxyphenoxy) piperidin-l-yl] phenoxymethyl } -2 , 3- dihydroimidazo [2 , 1-b] oxazole

Imidazo[2,1-b]oxazole, 2,3-dihydro-2-methyl-6-nitro-2-[[4-[4-[4-(trifluoromethoxy)phenoxy]-1-piperidinyl]phenoxy]methyl]-, (2R)-

(R)-2-methyl-6-nitro-2-{4-[4-(4-trifluoromethoxyphenoxy)piperidin-1-yl]phenoxymethyl}-2,3-dihydroimidazo[2,1-b]oxazole

681492-22-8 CAS

Delamanid

C₂₅H₂₅F₃N₄O₆ : 534.48
[681492-22-8]

Delamanid (USAN, INN) is a drug for the treatment of multi-drug-resistant tuberculosis. It works by blocking the synthesis of mycolic acids in Mycobacterium tuberculosis, the organism which causes tuberculosis, thus destabilising its cell wall.^[2][3][4] The drug is approved in the EU under the trade name Deltyba (made by Otsuka Pharmaceutical).

It is on the World Health Organization’s List of Essential Medicines, the most important medications needed in a basichealth system.^[5]

Adverse effects

Delamanid prolongs QT interval.^[6]

Interactions

Delamanid is metabolised by the liver enzyme CYP3A4, wherefore strong inducers of this enzyme can reduce its effectiveness.^[6]

History

In phase II clinical trials, the drug was used in combination with standard treatments, such as four or five of the drugsethambutol, isoniazid, pyrazinamide, rifampicin, aminoglycoside antibiotics, and quinolones. Healing rates (measured as sputum culture conversion) were significantly better in patients who additionally took delamanid.^[4][7]

The European Medicines Agency (EMA) recommended conditional marketing authorization for delamanid in adults with multidrug-resistant pulmonary tuberculosis without other treatment options because of resistance or tolerability. The EMA considered the data show that the benefits of delamanid outweigh the risks, but that additional studies were needed on the long-term effectiveness.^[8]

Delamanid was first approved by European Medicine Agency (EMA) on Apr 28, 2014, then approved by Pharmaceuticals and Medical Devices Agency of Japan (PMDA) on July 4, 2014. It was developed and marketed as Deltyba^® by Otsuka Pharmaceutical.

Delamanid is a novel bactericidal agent that interferes with the metabolism of the mycobacterium tuberculosis (MTB) cell walls. It is indicated for the treatment of pulmonary multi-drugresistant tuberculosis (MDR-TB) in adult patients.

Deltyba^® is available as tablets for oral use, containing 50 mg of free Delamanid, and the recommended dose is 100 mg twice daily for 24 weeks.

Delamanid, an antibiotic active against Mycobacterium tuberculosis strains, has been filed for approval in the E.U. and by Otsuka for the treatment of multidrug-resistant tuberculosis. In 2013, a positive opinion was received in the E.U. for this indication. Phase III trials for treatment of multidrug-resistant tuberculosis are under way in the U.S. Phase II study for the pediatric use is undergone in the Europe.

The drug candidate’s antimycobacterial mechanism of action is via specific inhibition of the synthesis pathway of mycolic acid, which is a cell wall component unique to M. tuberculosis.

In 2008, orphan drug designation was received in Japan for the treatment of pulmonary tuberculosis.

Tuberculosis (TB), an airborne lung infection, still remains a major public health problem worldwide. It is estimated that about 32% of the world population is infected with TB bacillus, and of those, approximately 8.9 million people develop active TB and 1.7 million die as a result annually according to 2004 figures. Human immunodeficiency virus (HIV) infection has been a major contributing factor in the current resurgence of TB. HIV-associated TB is widespread, especially in sub-Saharan Africa, and such an infectious process may further accelerate the resurgence of TB.

Moreover, the recent emergence of multidrug-resistant (MDR) strains ofMycobacterium tuberculosis that are resistant to two major effective drugs, isonicotinic acid hydrazide (INH) and rifampicin (RFP), has further complicated the world situation.

The World Health Organization (WHO) has estimated that if the present conditions remain unchanged, more than 30 million lives will be claimed by TB between 2000 and 2020. As for subsequent drug development, not a single new effective compound has been launched as an antituberculosis agent since the introduction of RFP in 1965, despite the great advances that have been made in drug development technologies.

Although many effective vaccine candidates have been developed, more potent vaccines will not become immediately available. The current therapy consists of an intensive phase with four drugs, INH, RFP, pyrazinamide (PZA), and streptomycin (SM) or ethambutol (EB), administered for 2 months followed by a continuous phase with INH and RFP for 4 months. Thus, there exists an urgent need for the development of potent new antituberculosis agents with low-toxicity profiles that are effective against both drug-susceptible and drug-resistant strains of M. tuberculosis and that are capable of shortening the current duration of therapy.

PATENT

US20060094767

(R)-2-bromo-4-nitro-1-(2-methyl-2-oxiranylmethyl)imidazole

4-[4-(4-Trifluoromethoxyphenoxy)piperidin-1-yl]phenol

ARE THE INTERMEDIATES

Example 1884

Production of (R)-2-methyl-6-nitro-2-{4-[4-(4-trifluoromethoxyphenoxy)piperidin-1-yl]phenoxymethyl}-2,3-dihydroimidazo[2,1-b]oxazole

4-[4-(4-Trifluoromethoxyphenoxy)piperidin-1-yl]phenol (693 mg, 1.96 mmol) was dissolved in N,N′-dimethylformamide (3 ml), and sodium hydride (86 mg, 2.16 mmol) was added while cooling on ice followed by stirring at 70-75° C. for 20 minutes. The mixture was cooled on ice. To the solution, a solution prepared by dissolving (R)-2-bromo-4-nitro-1-(2-methyl-2-oxiranylmethyl)imidazole (720 mg, 2.75 mmol) in N,N′-dimethylformamide (3 ml) was added followed by stirring at 70-75° C. for 20 minutes. The reaction mixture was allowed to return to room temperature, ice water (25 ml) was added, and the resultant solution was extracted with methylene chloride (50 ml) three times. The organic phases were combined, washed with water 3 times, and dried over magnesium sulfate. After filtration, the filtrate was concentrated, and the residue was purified by silica gel column chromatography (methylene chloride/ethyl acetate=3/1). Recrystallization from ethyl acetate/isopropyl ether gave (R)-2-methyl-6-nitro-2-{4-[4-(4-trifluoromethoxyphenoxy)piperidin-1-yl]phenoxymethyl}-2,3-dihydroimidazo[2,1-b]oxazole (343 mg, 33%) as a light yellow powder.

PATENT

WO 2010021409 AND http://worldwide.espacenet.com/publicationDetails/biblio?CC=IN&NR=203704A1&KC=A1&FT=D

FOR 2, 4 DINITROIMIDAZOLE

PATENT

WO2011093529A1

These patent literatures disclose Reaction Schemes A and B below as the processes for producing the aforementioned 2, 3-dihydroimidazo [2, 1-b] oxazole compound.

Reaction Scheme A:

wherein R¹ is a hydrogen atom or lower-alkyl group; R² is a substituted pxperidyl group or a substituted piperazinyl group; and X¹ is a halogen atom or a nitro group.

Reaction Scheme B:

wherein X² is a halogen or a group causing a substitution reaction similar to that of a halogen; n is an integer from 1 to 6; and R¹, R² and X¹ are the same as in Reaction Scheme A.

An oxazole com ound represented by Formula (la) :

, i.e., 2-methyl-6-nitro-2-{4- [4- (4- trifluoromethoxyphenoxy) piperidin-l-yl] phenoxymethyl }-2, 3- dihydroimidazo [2, 1-b] oxazole (hereunder, this compound may be simply referred to as “Compound la”) is produced, for example, by the method shown in the Reaction Scheme C below (Patent

Literature 3) . In this specification, the term “oxazole compound’ means an oxazole derivative that encompasses compounds that contain an oxazole ring or an oxazoline ring (dihydrooxazole ring) in the molecule.

Reaction Scheme C:

However, the aforementioned methods are unsatisfactory in terms of the yield of the objective compound. For example, the method of Reaction Scheme C allows the objective oxazole Compound (la) to be obtained from Compound (2a) at a yield as low as 35.9%. Therefore, alternative methods for producing the compound in an industrially advantageous manner are desired. Citation List

Patent Literature

PTL 1: WO2004/033463

PTL 2: WO2004/035547

PTL 3: WO2008/140090

Example 9

Production of (R) -2-methyl-6-nitro-2- { 4- [4- (4- trifluoromethoxyphenoxy) piperidin-l-yl] phenoxymethyl } -2 , 3- dihydroimidazo [2 , 1-b] oxazole

{R) -1- [ – {2 , 3-epoxy-2-methylpropoxy ) phenyl] -4- [4- ( trifluoromethoxy ) phenoxy ] piperidine (10.0 g, 23.6 mmol, optical purity of 94.3%ee), 2-chloro-4-nitroimidazole (4.0 g, 27.2 mmol), sodium acetate (0.4 g, 4.9 mmol), and t- butyl acetate (10 ml) were mixed and stirred at 100°C for 3.5 hours. Methanol (70 ml) was added to the reaction mixture, and then a 25% sodium hydroxide aqueous solution (6.3 g, 39.4 mmol) was added thereto dropwise while cooling with ice. The resulting mixture was stirred at 0°C for 1.5 hours, and further stirred at approximately room

temperature for 40 minutes. Water (15 ml) and ethyl acetate (5 ml) were added thereto, and the mixture was stirred at 45 to 55°C for 1 hour. The mixture was cooled to room temperature, and the precipitated crystals were collected by filtration. The precipitated crystals were subsequently washed with methanol (30 ml) and water (40 ml) . Methanol (100 ml) was added to the resulting

crystals, followed by stirring under reflux for 30 minutes. The mixture was cooled to room temperature. The crystals were then collected by filtration and washed with methanol (30 ml) . The resulting crystals were dried under reduced pressure, obtaining 9.3 g of the objective product (yield: 73%) .

Optical purity: 99.4%ee.

PATENT

Synthesis and antituberculosis activity of a novel series of optically active 6-nitro-2,3-dihydroimidazo[2,1-b]oxazoles
J Med Chem 2006, 49(26): 7854

http://pubs.acs.org/doi/abs/10.1021/jm060957y

(R)-2-Methyl-6-nitro-2-{4-[4-(4-trifluoromethoxyphenoxy)piperidin-1-yl]phenoxymethyl}-2,3-dihydroimidazo[2,1-b]oxazole (19,  DELAMANID).

To a mixture of 27 (127.56 g, 586.56 mmol) and 4-[4-(4-trifluoromethoxyphenoxy)piperidin-1-yl]phenol (28g) (165.70 g, 468.95 mmol) in N,N-dimethylformamide (1600 mL) was added 60% sodium hydride (22.51 g, 562.74 mmol) at 0 °C portionwise. After the mixture was stirred at 50 °C for 2 h under a nitrogen atmosphere, the reaction mixture was cooled in an ice bath and carefully quenched with ethyl acetate (230 mL) and ice water (50 mL). The thus-obtained mixture was poured into water (3000 mL) and stirred for 30 min. The resulting precipitates were collected by filtration, washed with water, and dried at 60 °C overnight. This crude product was purified by silica gel column chromatography using a dichloromethane and ethyl acetate mixture (5/1) as solvent. The appropriate fractions were combined and evaporated under reduced pressure. The residue was recrystallized from ethyl acetate (1300 mL)−isopropyl alcohol (150 mL) to afford 19 (119.11 g, 48%) as a pale yellow crystalline powder.

Mp 195−196 °C.

¹H NMR (CDCl₃) δ 1.77 (3H, s), 1.87−2.16 (4H, m), 2.95−3.05 (2H, m), 3.32−3.41 (2H, m), 4.02 (1H, d, J = 10.2 Hz), 4.04 (1H, d, J = 10.2 Hz), 4.18 (1H, J = 10.2 Hz), 4.36−4.45 (1H, m), 4.49 (1H, d, J = 10.2 Hz), 6.76 (2H, d, J = 6.7 Hz), 6.87−6.94 (4H, m), 7.14 (2H, d, J = 8.6 Hz), 7.55 (1H, s).

[α  −9.9° (c 1.01, CHCl₃).

MS (DI) m/z 535 (M⁺ + 1). Anal. (C₂₅H₂₅F₃N₄O₆) C, H, N.

http://pubs.acs.org/doi/suppl/10.1021/jm060957y/suppl_file/jm060957ysi20061113_095044.pdf

CLIPS

Delamanid (Deltyba)
Marketed by Otsuka, delamanid was approved in both the European Union and Japan in 2014 as part of combination therapies for
multi-drug resistant tuberculosis (TB). Because delamanid exhibited no adverse drug–drug interactions, it has found utility as a
combination therapy with standard antiretroviral drugs indicated for TB. Delamanid blocks mycolic acid biosynthesis in ycobacterium
tuberculosis, which allows its cell wall to be penetrated by small molecule antivirals.92

Although delamanid possesses a rather linear structure capable of a variety of retrosynthetic disconnections, the most likely scale
synthesis is a convergent approach involving two key synthons—diol 82 and piperidine 81, as is outlined in Scheme 13.93–95
Preparation of 82 proceeded through a Sharpless Asymmetric Epoxidation of commercial alcohol 86, followed by a diastereoselective
epoxide ring opening with 4-bromophenol to afford key diol 82 in 76% for the two step sequence (Scheme 14).93–96
Piperidine 81 was concurrently prepared by first generating biaryl ether 79, which arose from a substitution reaction between
pyridine N-oxide 77 and phenol 78 that proceeded in 86% yield. Next, removal of the N-oxide functionality by means of catalytic
hydrogenation under mild pressure and neutral conditions afforded diaryl ether 80 in excellent yield. Reduction of the pyridine
to the corresponding piperidine (81) was affected through the use of catalytic hydrogenation as well, this time under acidic
conditions and elevated pressures relative to the N-oxide reduction.95,97 At this juncture, subjection of piperidine 81 to Buchwald–
Hartwig conditions in the presence of diol subunit 82

(preparation described in Scheme 14) delivered diol 83. A two-step elimination to deliver enantiopure epoxide 84 set the stage for an
interesting cascade reaction to arrive at delamanid (XI) directly— the initial alkylation of the epoxide by imidazole 85 proceeded
under basic conditions with sodium acetate which then underwent an intramolecular nucleophilic substitution reaction by the liberated alcohol on the pendant imidazole chloride in the presence of sodium hydroxide. The reaction sequence proceeded in 73%
yield to provide delamanid (XI) as a free base.96

92. Blair, H. A.; Scott, L. J. Drugs 2015, 75, 91.
93. Tsubouchi, H.; Sasaki, H.; Kuroda, H.; Itotani, M.; Hasegawa, T.; Haraguchi, Y.;Kuroda, T.; Matsuzaki, T. US Patent 2006094767A1, 2006.
94. Sasaki, H.; Haraguchi, Y.; Itotani, M.; Kuroda, H.; Hashizume, H.; Tomishige,T.; Kawasaki, M.; Matsumoto, M.; Komatsu, M.; Tsubouchi, H. J. Med. Chem.2006, 49, 7854.
95. Goto, F.; Takemura, N.; Otani, T.; Hasegawa, T.; Tsubouchi, H.; Utsumi, N.; Fujita, S.; Kuroda, H.; Shitsuta, T.; Sasaki, H. US2012130082A1, 2012.
96. Yamamoto, A.; Shinhama, K.; Fujita, N.; Aki, S.; Ogasawara, S.; Utsumi, N. WOPatent 2011093529A1, 2011.

References

17181168	12-28-2006	Synthesis and antituberculosis activity of a novel series of optically active 6-nitro-2,3-dihydroimidazo[2,1-b]oxazoles.	Journal of medicinal chemistry
17132069	11-1-2006	OPC-67683, a nitro-dihydro-imidazooxazole derivative with promising action against tuberculosis in vitro and in mice.	PLoS medicine

18691051

1-1-2008

New anti-tuberculosis drugs with novel mechanisms of action.

Current medicinal chemistry

21069962

11-11-2010

Synthesis and Structure-Activity Relationships of Aza- and Diazabiphenyl Analogues of the Antitubercular Drug (6S)-2-Nitro-6-{[4-(trifluoromethoxy)benzyl]oxy}-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazine (PA-824).

Journal of medicinal chemistry

22421275	5-1-2012	Tuberculosis: the drug development pipeline at a glance.	European journal of medicinal chemistry
22148391	1-12-2012	Structure-activity relationships for amide-, carbamate-, and urea-linked analogues of the tuberculosis drug (6S)-2-nitro-6-{[4-(trifluoromethoxy)benzyl]oxy}-6,7-dihydro-5H-imidazo[2,1-b][1,3]oxazine (PA-824).	Journal of medicinal chemistry

US2009227630	9-11-2009	Pharmaceutical Composition Achieving Excellent Absorbency of Pharmacologically Active Substance
US2009018169	1-16-2009	Sulfonamide Derivatives for the Treatment of Bacterial Infections

WO2004033463A1	Oct 10, 2003	Apr 22, 2004	Otsuka Pharma Co Ltd	2,3-DIHYDRO-6-NITROIMIDAZO[2,1-b]OXAZOLES
WO2004035547A1	Oct 14, 2003	Apr 29, 2004	Otsuka Pharma Co Ltd	1-substituted 4-nitroimidazole compound and process for producing the same
WO2008140090A1	May 7, 2008	Nov 20, 2008	Otsuka Pharma Co Ltd	Epoxy compound and method for manufacturing the same
JP2009269859A *	Title not available

Delamanid

Systematic (IUPAC) name
(2R)-2-Methyl-6-nitro-2-[(4-{4-[4-(trifluoromethoxy)phenoxy]-1-piperidinyl}phenoxy)methyl]-2,3-dihydroimidazo[2,1-b][1,3]oxazole
Clinical data
Trade names	Deltyba
AHFS/Drugs.com	International Drug Names
Routes of administration	Oral (film-coated tablets)
Legal status
Legal status	℞ (Prescription only)
Pharmacokinetic data
Protein binding	≥99.5%
Metabolism	in plasma by albumin, in liver by CYP3A4 (to a lesser extent)
Biological half-life	30–38 hours
Excretion	not excreted in urine[1]
Identifiers
CAS Number	681492-22-8
ATC code	J04AK06 (WHO)
PubChem	CID 6480466
ChemSpider	4981055
ChEMBL	CHEMBL218650
Synonyms	OPC-67683
Chemical data
Formula	C25H25F3N4O6
Molar mass	534.48 g/mol

//////////////////////////681492-22-8 , Delamanid, Deltyba, Otsuka Pharmaceutical

FC(F)(F)Oc5ccc(OC4CCN(c3ccc(OC[C@@]2(Oc1nc(cn1C2)[N+]([O-])=O)C)cc3)CC4)cc5

Prucalopride (Resolor)

Drug Name：Prucalopride Succinate

Trade Name：Resolor^®, MOA：Serotonin (5-HT4) receptor agonist, Indication：Chronic constipation

Company：Shire (Originator) , Johnson & Johnson

APPROVED EU 2009-10-15

CHINA 2014-01-21

COA  NMR  HPLC CLICK

Prucalopride (brand name Resolor, developed by Johnson & Johnson and licensed to Movetis) is a drug acting as a selective, high affinity 5-HT₄ receptor agonist^[1] which targets the impaired motility associated with chronic constipation, thus normalizing bowel movements.^{[2][3][4][5][6][7]} Prucalopride was approved for use in Europe in 2009,^[8] in Canada (named Resotran) on December 7, 2011^[9] and in Israel in 2014^[10] but it has not been approved by the Food and Drug Administration for use in the United States. The drug has also been tested for the treatment of chronic intestinal pseudo-obstruction.^[11][12]

Mechanism of action

Prucalopride, a first in class dihydro-benzofuran-carboxamide, is a selective, high affinity serotonin (5-HT₄) receptor agonist with enterokinetic activities.^[13] Prucalopride alters colonic motility patterns via serotonin 5-HT₄ receptor stimulation: it stimulates colonic mass movements, which provide the main propulsive force for defecation.

The observed effects are exerted via highly selective action on 5-HT₄ receptors:^[13] prucalopride has >150-fold higher affinity for 5-HT₄ receptors than for other receptors.^[1][14] Prucalopride differs from other 5-HT₄ agonists such as tegaserod and cisapride, which at therapeutic concentrations also interact with other receptors (5-HT_1B/D and the cardiac human ether-a-go-go K⁺ or hERG channelrespectively) and this may account for the adverse cardiovascular events that have resulted in the restricted availability of these drugs.^[14] Clinical trials evaluating the effect of prucalopride on QT interval and related adverse events have not demonstrated significant differences compared with placebo.^[13]

Pharmacokinetics

Prucalopride is rapidly absorbed (C_max attained 2–3 hours after single 2 mg oral dose) and is extensively distributed. Metabolism is not the major route of elimination. In vitro, human liver metabolism is very slow and only minor amounts of metabolites are found. A large fraction of the active substance is excreted unchanged (about 60% of the administered dose in urine and at least 6% in feces).Renal excretion of unchanged prucalopride involves both passive filtration and active secretion. Plasma clearance averages 317 ml/min, terminal half-life is 24–30 hours,^[15] and steady-state is reached within 3–4 days. On once daily treatment with 2 mg prucalopride, steady-state plasma concentrations fluctuate between trough and peak values of 2.5 and 7 ng/ml, respectively.^[13]

In vitro data indicate that prucalopride has a low interaction potential, and therapeutic concentrations of prucalopride are not expected to affect the CYP-mediated metabolism of co-medicated medicinal products.^[13]

Efficacy

The primary measure of efficacy in the clinical trials is three or more spontaneous complete bowel movements per week; a secondary measure is an increase of at least one complete spontaneous bowel movement per week.^[7][16][17] Further measures are improvements in PAC-QOL^[18] (a quality of life measure) and PAC-SYM^[19] (a range of stool,abdominal, and rectal symptoms associated with chronic constipation). Infrequent bowel movements, bloating, straining, abdominal pain, and defecation urge with inability to evacuate can be severe symptoms, significantly affecting quality of life.^{[20][21][22][23][24]}

In three large clinical trials, 12 weeks of treatment with prucalopride 2 and 4 mg/day resulted in a significantly higher proportion of patients reaching the primary efficacy endpoint of an average of ≥3 spontaneous complete bowel movements than with placebo.^[7][16][17] There was also significantly improved bowel habit and associated symptoms, patient satisfaction with bowel habit and treatment, and HR-QOL in patients with severe chronic constipation, including those who did not experience adequate relief with prior therapies (>80% of the trial participants).^[7][16][17] The improvement in patient satisfaction with bowel habit and treatment was maintained during treatment for up to 24 months; prucalopride therapy was generally well tolerated.^[25][26]

Side effects

Prucalopride has been given orally to ~2700 patients with chronic constipation in controlled clinical trials. The most frequently reported side effects are headache andgastrointestinal symptoms (abdominal pain, nausea or diarrhea). Such reactions occur predominantly at the start of therapy and usually disappear within a few days with continued treatment.^[13]

Approval

In the European Economic Area, prucalopride was originally approved for the symptomatic treatment of chronic constipation in women in whom laxatives fail to provide adequate relief.^[13] Subsequently, it has been approved by the European Commission for use in adults – that is, including male patients – for the same indication.^[27]

Contraindications

Prucalopride is contraindicated where there is hypersensitivity to the active substance or to any of the excipients, renal impairment requiring dialysis, intestinal perforation orobstruction due to structural or functional disorder of the gut wall, obstructive ileus, severe inflammatory conditions of the intestinal tract, such as Crohn’s disease, and ulcerative colitis and toxic megacolon/megarectum.^[13]

CLIP

Prucalopride succinate, a first-in-class dihydrobenzofurancarboxamide, is a selective serotonin (5-HT4) receptor agonist.86–94 The drug, marketed under the brand name Resolor, possesses enterokinetic activity and was developed by the Belgian-based pharmaceutical firm Movetis. Prucalopride alters colonic motility patterns via serotonin 5-HT4 receptor stimulation, triggering the central propulsive force for defecation.95–97 The preparation of prucalopride succinate begins with the commercially available salicylic aniline 124 (Scheme 18). Acidic esterification, acetylation of the aniline nitrogen atom, and ambient-temperature chlorination via sulfuryl chloride (SO2Cl2) converted aminophenol 124 to acetamidoester 125 in 83% yield over the course of three steps.98–102 An unique set of conditions involving sodium tosylchloramide (chloramine T) trihydrate and sodium iodide were then employed to convert 125 to o-phenolic iodide 126, which then underwent sequential Sonogashira/cyclization reaction utilizing TMS-acetylene with tetramethylguanidine (TMG) in the presence of silica gel to furnish the benzofuran progenitor of 127.103 Hydrogenation of this intermediate benzofuranyl Sonagashira product saturated the 2,3-benzofuranyl bond while leaving the chlorine atom intact, ultimately delivering dihydrobenzofuran 127 in excellent yield for the two step sequence. Base-induced saponification and acetamide removal gave rise to acid 128. This acid was activated as the corresponding mixed anhydride and treated with commercial piperidine 129 to construct prucalopride which was stirred at room temperature for 24 h in ethanolic succinic acid to provide prucalopride succinate (XI). The yield for the formation of the salt was not provided.

86. Briejer, M. R.; Bosmans, J. P.; Van Daele, P.; Jurzak, M.; Heylen, L.; Leysen, J. E.;Prins, N. H.; Schuurkes, J. A. J. Eur. J. Pharmacol. 2001, 423, 71.
87. Briejer, M. R.; Prins, N. H.; Schuurkes, J. A. J. Neurogastroenterol. Motil. 2001, 13,465.
88. Coggrave, M.; Wiesel, P. H.; Norton, C. Cochrane Database Syst. Rev. 2006.CD002115.
89. Coremans, G.; Kerstens, R.; De Pauw, M.; Stevens, M. Digestion 2003, 67, 82.
90. De Winter, B. Y.; Boeckxstaens, G. E.; De Man, J. G.; Moreels, T. G.; Schuurkes, J.A. J.; Peeters, T. L.; Herman, A. G.; Pelckmans, P. A. Gut 1999, 45, 713.
91. Emmanuel, A. V.; Roy, A. J.; Nicholls, T. J.; Kamm, M. A. Aliment. Pharmacol.Ther. 2002, 16, 1347.
92. Frampton, J. E. Drugs 2009, 69, 2463.
93. Krogh, K.; Bach Jensen, M.; Gandrup, P.; Laurberg, S.; Nilsson, J.; Kerstens, R.;De Pauw, M. Scand. J. Gastroenterol. 2002, 37, 431.
94. Pau, D.; Workman, A. J.; Kane, K. A.; Rankin, A. C. J. Pharmacol. Exp. Ther. 2005,313, 146.
95. De Maeyer, J. H.; Schuurkes, J. A. J.; Lefebvre, R. A. Br. J. Pharmacol. 2009, 156,362.
96. Irving, H. R.; Tochon-Danguy, N.; Chinkwo, K. A.; Li, J. G.; Grabbe, C.; Shapiro,M.; Pouton, C. W.; Coupar, I. M. Pharmacology 2010, 85, 224.
97. Ray, A. M.; Kelsell, R. E.; Houp, J. A.; Kelly, F. M.; Medhurst, A. D.; Cox, H. M.;Calver, A. R. Eur. J. Pharmacol. 2009, 604, 1.
98. Baba, Y.; Usui, T.; Iwata, N. EP 640602 A1, 1995.
99. Fancelli, D.; Caccia, C.; Severino, D.; Vaghi, F.; Varasi, M. WO 9633186 A1,1996.
100. Hirokawa, Y.; Fujiwara, I.; Suzuki, K.; Harada, H.; Yoshikawa, T.; Yoshida, N.;Kato, S. J. Med. Chem. 2003, 46, 702.
101. Kakigami, T.; Usui, T.; Tsukamoto, K.; Kataoka, T. Chem. Pharm. Bull. 1998, 46,42.
102. Van Daele, G. H. P.; Bosmans, J.-P. R. M. A.; Schuurkes, J. A. J. WO 9616060 A1,1996.
103. Candiani, I.; DeBernadinis, S.; Cabri, W.; Marchi, M.; Bedeschi, A.; Penco, S.Synlett 1993, 269.

PAPER

Synlett 1993, 269

https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-1993-22663

PAPER

Chem. Pharm. Bull. 1998, 46,42.

https://www.jstage.jst.go.jp/article/cpb1958/46/1/46_1_42/_article

https://www.jstage.jst.go.jp/article/cpb1958/46/1/46_1_42/_pdf

PATENT

US5948794

http://www.google.co.in/patents/US5948794

EXAMPLE 1

In trichloromethane (135 ml) 4-amino-5-chloro-2,3-dihydro-7-benzofurancarboxylic acid (0.05 mol) (the preparation of which was described in EP-0,389,037-A) was suspended and cooled to ±5° C. N,N-diethylethanamine (0.05 mol) was added dropwise at a temperature below 10° C. Ethyl chloroformate (0.05 mol) was added dropwise and the reaction mixture was stirred for 40 min. while keeping the temperature below 10° C. The resulting mixture was added dropwise over a 20-min period to a solution of 1-(3-methoxypropyl)-4-piperidinamine (0.05 mol) in trichloromethane (35 ml). The cooling bath was removed and the reaction mixture was stirred for 150 min. Said mixture was washed with water (50 ml). The precipitate was filtered off over a glass filter and washed with water and CHCl₃. The filtrate was separated in it’s layers. The separated organic layer was washed with water (50 ml)+a 50% NaOH solution (1 ml), dried, filtered and the solvent was evaporated. The residue was stirred in 2-propanol (100 ml). This mixture was acidified with HCl/2-propanol (7.2 ml; 5.29 N). The mixture was stirred for 16 hours at room temperature and the resulting precipitate was filtered off, washed with 2-propanol (15 ml) and dried (vacuum; 50° C.), yielding 12.6 g (62%) of 4-amino-5-chloro-2,3-dihydro-N- 1-(3-methoxypropyl)-4-piperidinyl!-7-benzofurancarboxamide monohydrochloride (comp. 1).

US5854260

http://www.google.co.in/patents/US5854260

EXPERIMENTAL PART EXAMPLE 1

In trichloromethane (135 ml) 4-amino-5-chloro-2,3-dihydro-7-benzofurancarboxylic acid (0.05 mol) (the preparation of which was described in EP-0,389,037-A) was suspended and cooled to ±5° C. N,N-diethylethanamine (0.05 mol) was added dropwise at a temperature below 10° C. Ethyl chloroformate (0.05 mol) was added dropwise and the reaction mixture was stirred for 40 min. while keeping the temperature below 10° C. The resulting mixture was added dropwise over a 20-min period to a solution of 1-(3-methoxypropyl)-4-piperidinamine (0.05 mol) in trichloromethane (35 ml). The cooling bath was removed and the reaction mixture was stirred for 150 min. Said mixture was washed with water (50 ml). The precipitate was filtered off over a glass filter and washed with water and CHCl₃. The filtrate was separated in it’s layers. The separated organic layer was washed with water (50 ml)+ a 50% NaOH solution (1 ml), dried, filtered and the solvent was evaporated. The residue was stirred in 2-propanol (100 ml). This mixture was acidified with HCl/2-propanol (7.2 ml; 5.29 N). The mixture was stirred for 16 hours at room temperature and the resulting precipitate was filtered off, washed with 2-propanol (15 ml) and dried (vacuum; 50° C.), yielding 12.6 g (62%) of 4-amino-5-chloro-2,3-dihydro-N- 1-(3-methoxypropyl)-4-piperidinyl!-7-benzofurancarboxamide monohydrochloride (comp. 1).

PATENT

WO199616060A1

http://www.google.co.in/patents/WO1996016060A1?cl=en

EP-0,389,037-A, published on September 26, 1990, N-(3-hydroxy-4-piperidin- yl) (dihydrobenzofuran or dihydro-2H-benzopyran)carboxamide derivatives are disclosed as having gastrointestinal motility stimulating properties. In our EP-0,445,862-A, published on September 11, 1991, N-(4-piperidinyl) (dihydrobenzo¬ furan or dihydro-2H-benzopyran)carboxamide derivatives are disclosed also having gastrointestinal motility stimulating properties.

The compound subject to the present application differs therefrom by showing superior enterokinetic properties.

The present invention concerns a compound of formula

and the pharmaceutically acceptable acid addition salts thereof.

The chemical name of the compound of formula (I) is 4-amino-5-chloro-2,3-dihydro-N- [l-(3-methoxypropyl)-4-piperidinyl]-7-benzofurancarboxamide.

Example 1

In trichloromethane (135 ml) 4-amino-5-chloro-2,3-dihydro-7-benzofurancarboxylic acid (0.05 mol) (the preparation of which was described in EP-0,389,037-A) was suspended and cooled to ± 5 °C. H,N-diethylethanamine (0.05 mol) was added dropwise at a temperature below 10 °C. Ethyl chloroformate (0.05 mol) was added dropwise and the reaction mixture was stirred for 40 min. while keeping the temperature below 10°C. The resulting mixture was added dropwise over a 20-min period to a solution of l-(3-methoxypropyl)-4-piperidinamine (0.05 mol) in trichloromethane (35 ml). The cooling bath was removed and the reaction mixture was stirred for 150 min. Said mixture was washed with water (50 ml). The precipitate was filtered off over a glass filter and washed with water and CHCI3. The filtrate was separated in it’s layers. The separated organic layer was washed with water (50 ml) + a 50% NaOH solution (1 ml), dried, filtered and the solvent was evaporated. The residue was stirred in 2-propanol (100 ml). This mixture was acidified with HCl/2-propanol (7.2 ml; 5.29 N). The mixture was stirred for 16 hours at room temperature and the resulting precipitate was filtered off, washed with 2-propanol (15 ml) and dried (vacuum; 50 °C), yielding 12.6 g (62%) of 4-amino-5-chloro-2,3-dihydro-M-[ 1 -(3-methoxypropyl)-4-piperidinyl]-7- benzofurancarboxamide monohydrochloride (comp. 1).

Example 2

A mixture of 4-amino-5-chloro-2,3-dihydro-N-(4-piperidinyl)-7-benzofuran- carboxamide(O.Olmol), l-chloro-3-methoxypropane (0.012mol), M,M-diethyl- ethanamine (2Jml) and KI (catalytic amount) in N,M-dimethylformamide (75ml) was stirred overnight at 50°C. The reaction mixture was cooled. The solvent was evaporated. The residue was purified by column chromatography over silica gel (eluent: CHCl3/(CH3OH/NH3) 97/3). The pure fractions were collected and the solvent was evaporated. The residue was dissolved in 2-propanol and converted into the hydrochloric acid salt (1:1) with HCl/2-propanol. The precipitate was filtered off and dried (vacuum; 80°C), yielding 1.40g (35%) of 4-amino-5-chloro-2,3-dihydro-N-[l-(3-methoxypropyl)- 4-piperidinyl]-7-benzofurancarboxamide monohydrochloride (comp. 1).

PAPER

Chinese Journal of Pharmaceuticals 2012, 43, 5-8.

CLIP

Chinese Patent CN 103012337 A report is as follows:

PAPER

Pharmaceutical & Clinical Research 2011, 19, 306-307.

CLIP

US5374637 (CN1045781, EP389037) and J. Het Chem, 1980,17 (6): 1333-5 reported synthetic route, as follows:

CLIP

Chinese Patent CN 104016949 A synthetic route reported as follows:

PATENT

CN104529960A

https://www.google.com/patents/CN104529960A?cl=zh

.

Example 1

1. Preparation of Compound II

Compound I (167. lg, Imol), triethylamine (111. lg, I. Imol) and methylene chloride (KMOg) added to the reaction flask, nitrogen cooled to 5 ° C, was slowly added dropwise trifluoroacetic anhydride (220. 5g, 1.05mol) / methylene chloride (150g) solution, maintaining the temperature throughout 5~15 ° C, dropping was completed, the reaction after 3 hours at room temperature, TLC (DCM = MeOH = 25: 1) The reaction was monitored to complete the reaction; the reaction mixture was slowly poured into ice water (560g) and stirred for 20 minutes, standing layer, the aqueous phase was separated, the organic phase was washed with saturated aqueous sodium bicarbonate (IOOg) wash sash; IM hydrochloric acid (IlOg) wash sash, then with saturated brine (200g) washed sash, magnesium sulfate (40g) dried, filtered and concentrated to give compound II (250. Ig), yield: 952%.

[0066] 2. Preparation of Compound III

[0067] Chloroacetyl chloride (101. 7g, 0. 9mol), nitrobenzene (20g) and dichloroethane (580 g) added to the reaction flask, nitrogen cooled to 5 ° C, was slowly added anhydrous trichloro aluminum powder (359. 2g, 2. 7mol), to keep the whole temperature 5~20 ° C, plus complete, insulation 15~25 ° C for 30 minutes to obtain a mixture A.

[0068] Compound II (. 236. 7g, 0 9mol) and dichloroethane (500g) added to the reaction flask, nitrogen cooled to 15 ° C; the mixture was added Compound II A quick solution, plus complete, rapid heating 65~75 ° C, 1 hours later once every 15 minutes in the control, monitoring TLC (DCM = MeOH = 50: 1) to complete the reaction; the reaction mixture was immediately poured into ice water (800g) and stirred for 30 minutes, controlling the temperature between 15~25 ° C, the organic phase was separated, the organic phase washed with water (180g) was washed with saturated brine (240g), dried over magnesium sulfate (45g) was dried, filtered and concentrated to give crude compound III (303 . 2g).

[0069] Take the crude compound III (291. 3g) / ethanol 1 dichloromethane: 1 solution (1500ml) was dissolved, and then adding activated carbon (14. 5g) was refluxed for one hour, cooled to room temperature filtered and the filtrate concentrated at room temperature to 600~ 650g, stop and concentrated down to 5~10 ° C, filtered to give a yellow solid (204. 7g); the resulting yellow solid (207. 6g) in tetrahydrofuran (510g) was purified, reduced to 10~15 ° C, filtered, The filter cake was washed with tetrahydrofuran (90g) dip, dried under vacuum to give compound III (181. 3g), yield: 61.7% billion

[0070] 3. Preparation of Compound IV

[0071] Compound 111 (! 169.68,0.5 11〇1), methanol (5,801,111) and sodium acetate (123.38,1.5111〇1) was added to the reaction flask. After 6 hours of reaction, began TLC (DCM: MeOH = 30: 1 ) the reaction was monitored to completion of the reaction; the reaction mixture was cooled to room temperature, concentrated, and the residue with ethyl acetate (500g) and water (200g) was dissolved, the organic phase was separated, the organic phase was washed with 2M sodium hydrogen carbonate (120g) was washed, then with saturated brine (IOOg), dried over magnesium sulfate (50g) was dried, filtered and concentrated to 250~280g, cooled to room temperature with stirring was added cyclohexane (200 g of), after stirring for 1 hour and then filtered and dried to obtain compound IV (126. 7g), yield: 83.4% billion

[0072] 4. Preparation of Compound V

[0073] Compound IV (12L 2g, 0. 4mol), methanol (380g) and Raney-Ni (12. 5g) added to the autoclave, purged with nitrogen, hydrogen is introduced (3. Ompa), the reaction was heated to 45 ° C after 8 hours, TLC (DCM = MeOH = 30: 1) to monitor the reaction, to complete the reaction, cooled to room temperature and pressure, and then purged with nitrogen, the reaction solution was filtered and concentrated to give crude compound V (103. 7g), taking compound V crude product (103g) was refluxed with ethyl acetate (420g) (1 hour) was purified, cooled to room temperature and stirred for 30 minutes and filtered to give a yellow solid was dried in vacuo to give compound V (76 8g.), yield: 663 %.

[0074] 5. Preparation of Compound VI

[0075] Compound ¥ (57.88,0.2111〇1), 1 ^ dimethylformamide (4.58) and acetonitrile (30 (^) was added to the reaction flask and heated 74~76 ° C; solution of N- chlorosuccinimide imide (. 26. 7g, 0 2mol) and acetonitrile (45g) was added dropwise over 30 minutes and maintaining the temperature finished 76~82 ° C, dropping was completed, the reaction was kept, after one hour the reaction started TLC (DCM: MeOH = 30: 1) to monitor the reaction, the reaction is complete the reaction solution cooled to 5~8 ° C, the filter cake was washed with water (210g) washed stirred, filtered, and dried in vacuo to give compound VI (57. 6g), yield. rate of 89.1%.

6. Preparation of Compound VII

Compound VI (48. 5g, 0. 15mol) and methanol (80g) added to the reaction flask, stirring at room temperature was added dropwise 4M aqueous sodium hydroxide (HOg), dropwise complete, for the reaction, 25 ° C~35 after 4 hours of reaction ° C, samples of about 7:00 adjust PH TLC (DCM = MeOH = 30: 1) to monitor the reaction, until the reaction was complete, down to 5~10 ° C, with 6M hydrochloric acid solution PH ~ 7. 5, half the solution was concentrated, then 2M hydrochloric acid solution PH ~ 7, reduced to 15~20 ° C was stirred for 30 minutes, filtered, the filter cake with methyl tert-butyl ether (70g) beating, filtration, and dried in vacuo to give compound VII (28. 7g), yield: 903%.

PAPER

Chem Pharm Bull 46 (1), 42-52 (1998) and Pharmaceutical and clinical study based on 2011 (4) 306-307 reported synthetic route is as follows:

Biological Activity

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

1

References

[1] Briejer MR, et al. Eur J Pharmacol, 2001, 423(1), 71-83.

[2] Priem E, et al. Neuropharmacology, 2012, 62(5-6), 2126-2135.

Clinical Trial Information( data from http://clinicaltrials.gov, updated on 2016-07-23)

References

External links

• Resolor (prucalopride)- Movetis

Prucalopride

Systematic (IUPAC) name
4-Amino-5-chloro-N-[1-(3-methoxypropyl)piperidin-4-yl]-2,3-dihydro-1-benzofuran-7-carboxamide
Clinical data
Trade names	Resolor, Resotran
AHFS/Drugs.com	International Drug Names
License data	EU EMA: Resolor
Pregnancy category	AU: B1 Not recommended
Routes of administration	Oral
Legal status
Legal status	AU: S4 (Prescription only) ℞ (Prescription only)
Identifiers
CAS Number	179474-81-8
ATC code	A06AX05 (WHO)
PubChem	CID 3052762
IUPHAR/BPS	243
ChemSpider	2314539
UNII	0A09IUW5TP
Chemical data
Formula	C18H26ClN3O3
Molar mass	367.870 g/mol

//////////Prucalopride succinate, Resolor, R-093877, R-108512, Resolor®, Resolor, Resotran, UNII:0A09IUW5TP, 179474-81-8 , R-093877,  R-108512, Shire , Johnson & Johnson, 179474-85-2, UNII-4V2G75E1CK, SHIRE,  2010,  LAUNCHED, JANNSEN , PHASE 3,  IRRITABLE BOWL SYNDROME

COCCCN1CCC(CC1)NC(=O)C2=CC(=C(C3=C2OCC3)N)Cl

Spironolactone

Spironolactone, Supra-puren, Suracton, спиронолактон, سبيرونولاكتون ,

螺内酯 , Abbolactone, Aldactide, SNL, Spiroctanie, Sprioderm, Verospirone,  Opianin

7α-Acetylthio-17α-hydroxy-3-oxopregn-4-ene-21-carboxylic acid γ-lactone

(1’S,2R,2’R,9’R,10’R,11’S,15’S)-9′-(acetylsulfanyl)-2′,15′-dimethylspiro[oxolane-2,14′-tetracyclo[8.7.0.0^2,7.0^11,15]heptadecan]-6′-ene-5,5′-dione

MF C₂₄H₃₂O₄S, MW 416.573 Da

Spironolactone, marketed under the brand name Aldactone among others, is a medication primarily used to treatfluid build-up due to heart failure, liver scarring, or kidney disease.^[1] Other uses include high blood pressure, low blood potassium that does not improve with supplementation, early puberty, excessive hair growth in women,^[1] and as a component of hormone replacement therapy for transgender women.^[6] It is taken by mouth.^[1]

Common side effects include electrolyte abnormalities particularly high blood potassium, nausea, vomiting, headache, a rash, and a decreased desire for sex. In those with liver or kidney problems extra care should be taken.^[1]Spironolactone has not been well studied in pregnancy and should not be used to treat high blood pressure of pregnancy.^[7] It is a steroid that blocks mineralocorticoid receptors. It also blocks androgen, and blocks progesterone. It belongs to a class of medications known as potassium-sparing diuretics.^[1]

Spironolactone was introduced in 1959.^[8][9] It is on the World Health Organization’s List of Essential Medicines, the most important medications needed in a basic health system.^[10] It is available as a generic medication.^[1] The wholesale cost in the developing world as of 2014 is between 0.02 and 0.12 USD per day.^[11] In the United States it costs about 0.50 USD per day.^[1]

Medical uses

Spironolactone is used primarily to treat heart failure, edematous conditions such as nephrotic syndrome or ascites in people with liver disease, essential hypertension, hypokalemia, secondary hyperaldosteronism (such as occurs with hepatic cirrhosis), and Conn’s syndrome (primary hyperaldosteronism). On its own, spironolactone is only a weak diuretic because it primarily targets the distal nephron (collecting tubule), where only small amounts of sodium are reabsorbed, but it can be combined with other diuretics to increase efficacy.

Spironolactone is an antagonist of the androgen receptor (AR) as well as an inhibitor of androgen production. Due to the antiandrogenic effects that result from these actions, it is frequently used off-label to treat a variety of dermatological conditions in which androgens, such as testosterone and dihydrotestosterone (DHT), play a role. Some of these uses include androgenic alopecia in men (either at low doses or as a topical formulation) and women, and hirsutism, acne, and seborrhea in women.^[12] Spironolactone is the most commonly used drug in the treatment of hirsutism in the United States.^[13] Higher doses of spironolactone are not recommended in males due to the high risk of feminization and other side effects. Similarly, it is also commonly used to treat symptoms of hyperandrogenism in polycystic ovary syndrome.^[14]

Spironolactone (SL) is known to be a potent aldosterone antagonist at mineralocorticoid steroid hormone receptors, and it is widely used in humans for the treatment of essential hypertension, congestive heat failure and refractory edema or hyperaldosteronism. However, the prolonged use of SL is associated with undesirable endocrine side effects such as gynecomastia and lose of libido in men and menstrual irregularities in women due to interaction of SL with gonadal steroid hormone biosynthesis and target cell gonadal steroid receptors.

The nature and prevalence of the undesirable side effects limit the usefulness of spironolactone as a therapeutic agent. Gynecomastia or tender breast enlargement has been found to occur in 10% of hypertensive patients using spironolactone for therapy as compared to 1% of men in the placebo group. Recent studies by Pitt, et al. with spironolactone have shown that in patients with congestive heart failure (CHF) taking digoxin and a loop diuretic—spironolactone therapy in conjunction with digitalis and ACE inhibitor—reduces mortality by 30%. See Pitt, B., et al., The Effect of Spironolactone on Morbidity and Mortality in Patients with Severe Heart Failure, Randomized Aldactone Evaluation Study Investigors; N. Engl. J. Med., 1999, 341:709-717. These authors stated that the 30% reduction in the risk of death among patients in the group receiving spironolactone could be attributed to a lower risk of both death from progressive heart failure and sudden death from cardiac arrhythmic causes. In addition, they found that the frequency of hospitalization for worsening heart failure is 35% lower in the spironolacotone treated group than in the placebo group. These authors concluded that patients who received spironolactone had a significant improvement in the symptoms of severe heart failure caused by systolic left ventricular dysfunction. Overall, 8% of the patients in the spironolactone group discontinued treatment because of adverse events. The purpose of the present invention is to make available the individual chiral isomers of spironolactone that would be effective in treating CHF and in reducing hypertension, and at the same time would be devoid of undesirable side effects such as gynecomastia, lose of libido in men, and menstrual irregularities in women.

Spironolactone is the name commonly used for a specific spirolactone that has the full chemical name 17-hydroxy-7-alpha-mercapto-3-oxo-17-alpha-pregn-4-ene-21-carboxylic acid gamma-lactone acetate. The term “spirolactone” denotes that a lactone 10 ring (i.e., a cyclic ester) is attached to another ring structure in a spiro configuration (i.e., the lactone ring shares a single carbon atom with the other ring). Spirolactones that are coupled to steroids are the most important class of spirolactones from a pharmaceutical perspective, so they are widely referred to in the pharmaceutical arts simply as spirolactones. As used herein, “spironolactone” refers to a molecule comprising a lactone structure coupled via a spiro configuration to a steroid structure or steroid derivative.

Spironolactone, its activities, and modes of synthesis and purification are described in a number of U.S. patents, notably U.S. Pat. Nos. 3,013,012, 4,529,811 and 4,603,128.

Intracellular receptors (IRs) form a class of structurally-related genetic regulators that act as ligand-dependent transcription factors. See Evans, R. M., “The Steroid and Thyroid Hormone Receptor Superfamily”, Science, May 13, 1988; 240(4854):889-95. Steroid receptors are a recognized subset of the IRs, including the progesterone receptor (PR), androgen receptor (AR), estrogen receptor (ER), which can be referred to collectively as the gonadal steroid receptors, glucocorticoid receptor (GR), and mineralocorticoid receptor (MR). Regulation of a gene by such factors requires both the IR itself and a corresponding ligand that has the ability to selectively bind to the IR in a way that affects gene transcription.

Ligands for the IRs can include low molecular weight native molecules, such as the hormones aldosterone, progesterone, estrogen and testosterone, as well as synthetic derivative compounds such as medroxyprogesterone acetate, diethylstilbesterol and 19-nortestosterone. These ligands, when present the fluid surrounding a cell, pass through the outer cell membrane by passive diffusion and bind to specific IR proteins to create a ligand/receptor complex. This complex then translocates to the cell’s nucleus, where it binds to a specific gene or genes present in the cell’s DNA. Once bound to DNA, the complex modulates the production of the protein encoded by that gene. In this regard, a compound that binds to an IR and mimics the effect of the native ligand is referred to as an “agonist”, while a compound that binds to an IR and inhibits the effect of the native ligand is called an “antagonist”.

The therapeutic mechanism of action of spironolactone involves binding to intracellular mineralocorticoid receptors (MRs) in kidney epithelial cells, thereby inhibiting the binding of aldosterone. Spironolactone has been found to counteract the sodium reabsorption and potassium excretion effects of aldosterone and other mineralocorticoids. Spironolactone has also been shown to interfere with testosterone biosynthesis, has anti-androgen action and inhibits adrenal aldosterone biosynthesis. Large doses of spironolactone in children appear to decrease the testosterone production rate.

Spironolactone is found to exhibit intra-individual variability of pharmacokinetic parameters and it presumably belongs to the group of drugs with high inter-subject variability. Spironolactone has poor water solubility and dissolution rate.

In order to prolong the half-life and decrease the side effects associated with spironolactone, syntheses of spironolactone derivatives have been developed (e.g. synthesis of mexrenone, prorenone, spirorenone). Slight modifications of the spironolactone steroid skeleton, e.g. such as formation of 11β-allenic and epoxy compounds, have been shown to effect important variations in the affinity and specificity for the mineralocorticoid receptor. These results suggest that it is possible to develop spironolactone analogues that do not interact with the androgen receptor or cytochrome P-450 and are therefore free of spironolactone undesirable side-effects.

METABOLISM

SYNTHESIS

METHOD 1 REF 150

REF 130, 150

METHOD 2 REF 140

METHOD 3 REF 150

Synthesis

Cella, John A.; Tweit, Robert C. (1959). Journal of Organic Chemistry 24: 1109. doi:10.1021/jo01090a019.

(See also part 1 and part 3)

SPECTROSCOPY UV

SPECTROSCOPY IR

KBR

The principal absorption peaks of the spectrum shown in Figure 5 were noted at 1765,
1693, 1673, 1240, 1178, 1135, 1123 and 1193 cm -1.

SPECTROSCOPY 1H NMR

SPECTROSCOPY 13C NMR

SPECTROSCOPY MASS SPECTRUM

130 J.A. Cola, E.A. Brown, and R.R. Burtner, 3. Org. Chem., 24, 1109(1959).

 140 Remington’s: The Science and Practice of Pharmacy, 19 t~ edn.Volume II, K.G. Alfonso, ed.; Mack Publishing Co., Pennsylvania (1995) p.1048.
150. G. Anner and H. Wehrli (Ciba-Geigy, A.-G.), German Often 2,625,723 (cl.C07J21/00), Dec,1976; Swiss Appl. 75/7, 696, 13Jun. 1975; pp. 37.

ANALYTICAL

• High-Performance Liquid Chromatographic Conditions
  Column	LiChrosorb RP-8, 5 μm. 150 × 4.6 mm I.D.
  Eluent	Acetonitrile-0.05 M phosphate buffer, pH 4 (45:55)
  Flow-rate	1 ml/min
  Temperature	25° C.
  Detector	UV detector, wavelength 286 nm or 271 nm
  Recorder	Chart speed 0.5 cm/min
  Sample loop	10 μl

• The concentration of canrenone is determined in plasma and urine samples by high-performance liquid chromatography (HPLC) with UV-detection. An aliquot of 300 ng of spironolactone derivative is added to the samples as internal standard, which are then extracted twice with 1 ml n-hexane-toluene (1:1, v/v). The organic phase is taken to dryness and re-dissolved in 250 μl HPLC eluent (methanol-water, 60:40, v/v). (25×4.6 mm; 5 μm). Detection is performed with the UV detector set at λ=285 nm.

Flurometric Method

Five ml of water is a reagent blank and 5 ml of working standards containing 0.05 μg and 0.20 μg of SC-9376 are carried through the entire procedure. Lower sales are read vs. the 0.05 μg standard at full scale, and higher samples vs. the 0.20 μg standard. Fluorescence readings are proportional to the concentrations of the standards in this range.

Pipette 0.2 ml of heparinized plasma into a 50-ml polyethylene-stoppered centrifuge tube, dilute to 5 ml with water and add 15 ml of methylene chloride (Du Pont refrigeration grade, redistilled). Shake for 30 seconds, centrifuge and discard the aqueous supernatant. Add 1 ml 0.1 N NaOH, shake 15 seconds, centrifuge and discard the supernatant. Transfer a 10-ml aliquot of the methylene chloride phase to another tube containing 2 ml of 65% aqueous sulfuric acid, shake 30 seconds, centrifuge and remove organic phase by aspiration. The material is allowed to stand at room temperature for about 1 hour and then about 1 ml of the sulfuric acid phase in transferred to a quartz cuvette. Fluorescence intensity is determined in an Aminco-Bowman spectrophotofluorometer (activation maximum, 465 nm).

Gas Liquid Chromatography

The GLC estimation is carried out on a Fractovap Model 251 series 2150 (Carlo Erba) instrument equipped with a Nickel-63 electron capture detector. A 6-foot, 0.4 mm internal diameter, U-shaped glass column, packed with OV-17 2% or XE-60 1% on gas chrom A, 100-120 mesh (Applied Science Lab) is conditioned for 3 days before use. Argon with 10% methane which passed through a molecular sieve before entering the column is used as the carrier gas. The conditions of analysis are: column 255° C., detector 275° C., carrier gas flow 30 ml/min. Samples are injected on the column with a 10 μl Hamilton syringe. The injector in not heated.

PATENT

https://www.google.com/patents/US20090325918

EXAMPLE 1Chiral Separation

The separation of 7 beta isomer of SL is schematically described below.

• Chromatographic Method for Isolation of SL Isomers

  The basic method is described in Chan, Ky, et al., J. Chromatog, Nov. 15, 1991:571 (1-2) 291-297. The separation is performed using spectra-physics HPLC instrument and UV variable wavelength detector set at 254 nm. For chiral separation, the chromatographic column is either a pre-packed 25 mm×4.6 mm ID Cyclobond 1 (5 μm particle size), or a pre-packed 150 mm×4 mm ID Resolvosil BSA-7 column (5 μm) operated using the conditions described herein.

  Analysis of the isomers present in the peaks in the chromatograms and their chiral extract purity analysis can be determined in each case by high resolution NMR spectroscopy using a chiral shift reagent. Based on this information and the determination of molecular weight by mass spectrometry and/or optical activity, structural configuration is assigned to each isomer. Eluted samples of isomers may be re-chromatographed in order to obtain adequate quantities of isomers having desired optical purity for study. For future use, reference standards that are optically pure will be compared for confirmation of purity and identity to the isolated isomers that are obtained after their chromatographic separation.

EXAMPLE 2Chemical Synthesis of Optical Isomers

As an example, the desire spironolactone 7-beta-isomer is synthesized following the scheme that is described below:

• Diene (i) is prepared from commercially available starting materials using methods well known in the art of chemical synthesis.
  Diene (i) is treated with acetic acid and the mixture is heated to reflux to yield 7-alpha-acetate ester (ii). The 7-alpha-ester (ii) is further subjected to nucleophilic substitution, followed by hydrolysis to obtain the 7-beta-isomer (iii). The 7-beta-isomer (iii) is then esterified with an acyl halide in the presence of a base to generate the desired spironolactone 7-beta-isomer (iv).

EXAMPLE 3Preparation of Radiolabeled Probe Compounds of the Invention

Using known methods, the compounds of the invention may be prepared as radiolabeled probes by carrying out their synthesis using precursors comprising at least one atom that is a radioisotope. The radioisotope is preferably selected from at least one of carbon (preferably

¹⁴

C), hydrogen (preferably

³

H), sulfur (preferably

³⁵

S), or iodine (preferably I). Such radiolabeled probes are conveniently synthesized by a radioisotope supplier specializing in customer synthesis of radiolabeled probe compounds. Such suppliers include Amersham Corporation, Arlington Heights, Ill.; Cambridge Isotope Laboratories, Inc., Andover, Mass.; SRI International, Menlo Park, Calif.; Wizard Laboratories, West Sacramento, Calif.; ChemSyn Laboratories, Lexena, Kans.; American Radiolabeled Chemicals, Inc., St. Louis, Mo.; and Moravek Biochemicals Inc., Brea, Calif.

Tritium labeled probe compounds are also conveniently prepared catalytically via platinum-catalyzed exchange in tritiated acetic acid, acid-catalyzed exchange in tritiated trifluoroacetic acid, or heterogeneous-catalyzed exchange with tritium gas. Tritium labeled probe compounds can also be prepared, when appropriate, by sodium borotritide reduction. Such preparations are also conveniently carried out as a custom radiolabeling by any of the suppliers listed in the preceding paragraph using the compound of the invention as substrate.

EXAMPLE 4Isolation and Purification Procedure

The optical isomers of spironolactones may be isolated from fluid sample such as urine or blood as follows:

Extraction from Urine

The urine sample is extracted with dichloromethane and the extract washed with NaOH (0.1 N) and then with water to neutrality. The residue obtained after evaporation of the dichloromethane extract is purified on TLC in three different systems: benzene-acetone-water, (150:100:0.4); chloroform-ethanol, (90:10); ethyl acetate-cyclohexane-ethanol, (45:25:10), using aldosterone as reference standard.

The extract is then purified by high performance liquid chromatography (HPLC) on a Waters 6000 A, 480 U.V. detector instrument with radial pressure. The extract is first run through a C

₁₈

10μ column using methanol-water (70:30) as the eluent, followed by a silica 5μ column using dichloromethane-methanol (95:5). In both cases, the rate of the eluent is 1.5 ml/min. A small part of the extract is subjected to heptafluorobutyrylation for GLC investigation.

References

Spironolactone

Systematic (IUPAC) name
7α-Acetylthio-17α-hydroxy-3-oxopregn-4-ene-21-carboxylic acid γ-lactone
Clinical data
Pronunciation	/spɪˌroʊnəˈlæktoʊn, spaɪ–, spə–, –ˈrɒ–, –noʊ–/or /ˌspaɪrənoʊˈlæktoʊn/[2][3][4]
Trade names	Aldactone
AHFS/Drugs.com	Monograph
MedlinePlus	a682627
Pregnancy category	AU: B3 US: C (Risk not ruled out)
Routes of administration	Oral[1]
Legal status
Legal status	UK: POM (Prescription only) US: ℞-only
Pharmacokinetic data
Protein binding	90%+[5]
Metabolism	Hepatic CYP450
Biological half-life	1.3-2 hours
Excretion	Urine, bile
Identifiers
CAS Number	52-01-7
ATC code	C03DA01 (WHO)
PubChem	CID 5833
IUPHAR/BPS	2875
DrugBank	DB00421
ChemSpider	5628
UNII	27O7W4T232
KEGG	D00443
ChEBI	CHEBI:9241
ChEMBL	CHEMBL1393
Chemical data
Formula	C24H32O4S
Molar mass	416.574 g/mol

///////Spironolactone, Supra-puren, Suracton, спиронолактон, سبيرونولاكتون ,

螺内酯 , Abbolactone, Aldactide, SNL, Spiroctanie, Sprioderm, Verospirone,  Opianin

O=C5O[C@@]4([C@@]3([C@H]([C@@H]2[C@H](SC(=O)C)C/C1=C/C(=O)CC[C@]1(C)[C@H]2CC3)CC4)C)CC5

Varenicline (Chantix™)

Varenicline

• MF C₁₃H₁₃N₃
• MW 211.26

Varenicline (trade name Chantix and Champix usually in the form of varenicline tartrate), is a prescription medication used to treatnicotine addiction. Varenicline is a nicotinic receptor partial agonist—it stimulates nicotine receptors more weakly than nicotine itself does. In this respect it is similar to cytisine and different from the nicotinic antagonist, bupropion, and nicotine replacement therapies(NRTs) like nicotine patches and nicotine gum. As a partial agonist it both reduces cravings for and decreases the pleasurable effects of cigarettes and other tobacco products. Through these mechanisms it can assist some patients to quit smoking.

バレニクリン酒石酸塩
Varenicline Tartrate

C₁₃H₁₃N₃C₄H₆O₆ : 361.35
[375815-87-5]

Medical uses

Varenicline is used for smoking cessation. In a 2009 meta-analysis varenicline was found to be more effective than bupropion (odds ratio 1.40) and NRTs (odds ratio 1.56).^[1]

A 2013 Cochrane overview and network meta-analysis concluded that varenicline is the most effective medication for tobacco cessation and that smokers were nearly three times more likely to quit on varenicline than with placebo treatment. Varenicline was more efficacious than bupropion or NRT and as effective as combination NRT for tobacco smoking cessation.^[2][3]

The United States’ Food and Drug Administration (US FDA) has approved the use of varenicline for up to twelve weeks. If smoking cessation has been achieved it may be continued for another twelve weeks.^[4]

Varenicline has not been tested in those under 18 years old or pregnant women and therefore is not recommended for use by these groups. Varenicline is considered a class C pregnancy drug, as animal studies have shown no increased risk of congenital anomalies, however, no data from human studies is available.^[5] An observational study is currently being conducted assessing for malformations related to varenicline exposure, but has no results yet.^[6] An alternate drug is preferred for smoking cessation during breastfeeding due to lack of information and based on the animal studies on nicotine.^[7]

Varenicline L-tartrate (Compound I) is the international commonly accepted name for 7,8,9,10- tetrahydro-6, 10-methano-6i7-pyrazino [2, 3- h] [3 ] benzazepme, (2R, 3R) -2 , 3-dihydroxybutanedioate (1:1) (which is also known as 5,8,14- tπazatetracyclo [10.3.1. O²‘¹¹. O⁴‘⁹] -hexadeca-2 (11) , 3, 5, 7, 9-pentaene, (2R, 3R)-2,3- dihydroxybutanedioate (1:1)) and has an empirical formula of C13H13N3 ^• C4H6O6 and a molecular weight of 361.35. Varenicline L-tartrate is a commercially marketed pharmaceutically active substance known to be useful for the treatment of smoking addiction.

(D

Varenicline L-tartrate is a partial agonist selective for (X₄β₂ nicotinic acetylcholine receptor subtypes. In the United States, varenicline L-tartrate is marketed under the name Chantix™ for the treatment of smoking cessation. Varenicline base and its pharmaceutically acceptable acid addition salts are described in U.S. Patent No. 6,410,550. In particular, Example 26 of U.S. Patent No. 6,410,550 describes the preparation of varenicline hydrochloride salt using 1- (4 , 5-dinitro-10- aza-tπcyclo [6.3.1.O²‘⁷] dodeca-2, 4, 6-trien-10-yl) -2,2,2- tπfluoroethanone (compound of formula (III)) as starting compound. On the other hand, Example HA) of U.S. Patent No. 6,410,550 illustrates the preparation of compound of formula (III) via nitration of compound of formula (II) using an excess of nitronium triflate (>4 equiv) as a nitrating agent. The process disclosed in U.S. Patent No. 6,410,550 is depicted in Scheme 1.

VareniclineΗCl

Scheme 1

However, Coe et al., J. Med. Chem., 48, 3474 (2005), describes the same process and examples as U.S. Patent No. 6,410,550, and it also reveals that this process affords intermediate ortho-4 , 5-dinitrocompound of formula (III) together with the meta-3, 5-dinitro- isomer (i.e. the meta-dinitrocompound) in a ratio 9:1. The presence of the meta-dinitrocompound may affect not only the purity of the intermediate compound of formula III but it may also have an effect on the purity of the final varenicline tartrate, given that it can be carried along the synthetic pathway and/or it can also give rise to other derivative impurities. Thereby, as well as in U.S. Patent No. 6,410,550, in order to isolate pure compound of formula (III) , the raw product is triturated with ethyl acetate/hexane to afford compound of formula (III) with 77% yield. Additionally, the mother liquor is purified by chromatography on silica gel to improve the yield to a total of 82.8%. However, this process is not desirable for industrial implementation since it requires extensive and complicated purification procedures, i.e. trituration of the solid product along with column chromatography purification of the mother liquor, which is not very efficient or suitable for industrial scale-up.

Several improved processes for the synthesis of varenicline or its salts have been reported in the literature (e.g. WO2006/090236) . However, none of these processes tackle the optimization of the purification step of compound of formula (III).

There is therefore the need for providing an improved process for the preparation of varenicline L- tartrate which involves simple experimental procedures well suited to industrial production, which avoids the use of column chromatography purifications, and which affords high pure varenicline L-tartrate which hence can be used directly as a starting product for the preparation of the marketed pharmaceutical speciality.

Additionally, it has been observed that varenicline L-tartrate is usually obtained as a yellow solid under – A –

standard synthetic conditions. In this regard, colour must be attributed to the presence of some specific impurities that may or may not be detectable by conventional methods such as HPLC. The presence of impurities may adversely affect the safety and shelf life of formulations. In this connection, International application No. WO2006/090236 describes the isolation of vareniclme L- tartrate as a white solid. However, in order to remove coloured impurities, the varenicline L-tartrate obtained in WO2006/090236 is treated with a particular activated carbon having a specific grade (i.e. Darco KB-B™) . In fact, Example 5 of WO2006/090236 describes a large reprocessing step which comprises: dissolving varenicline L-tartrate in water, adding toluene, basifying with NaOH aqueous solution, collecting the toluene phase containing varenicline free base, distilling, adding methanol, azeotropically distilling the mixture, and adding more methanol to obtain a methanolic solution containing varenicline free base, adding Darco KB-B™ (10% w/w) , stirring for one hour, filtering through a pad of celite, and treating with L-tartaric acid to give varenicline L- tartrate salt as a white solid. Further, WO2006/090236 provides the absorbance at 430 nm of a varenicline L- tartrate salt solution, either in dichloromethane or in toluene, with or without using Darco KB-B™ activated carbon. However, this measure cannot be used to corroborate the whiteness of the solid varenicline L- tartrate. In addition, Example 3 of International application No. WO2002/092089, also disclose the preparation of varenicline L-tartrate polymorphic form C (i.e. a hydrate polymorph) as a white precipitate. Therefore, there is also a need for a simple and efficient method for preparing varenicline L-tartrate with enhanced whiteness and having a high purity.

SYNTHESIS

Synthesis of Intermediate VIII

Paper

J. Med. Chem. 48, 3474 (2005).

http://pubs.acs.org/doi/pdf/10.1021/jm050069n

PATENT

https://www.google.com/patents/WO2001062736A1?cl=en

CLIP

Profiles of Drug Substances, Excipients and Related Methodology, Volume 37

edited by Harry G. Brittain

SYNTHESIS

CLIP

Scheme (I) compound patent US6410550B1 is provided adjacent difluorobromobenzene as raw materials by DA reaction, oxidation, cyclization, debenzylation get varenicline intermediate (II). The synthesis route is as follows:

Patent CN101693712A mainly given varenicline intermediate (II) The preparation process is different from the compound patented. After the five-step method patents cited compounds. The entire route is longer, while using a large number of precious metal catalysts and reaction conditions need very strict control, inappropriate EVAL industry production.

PATENT

CN 102827079

A varenicline intermediate 2,3, 4, 5-tetrahydro-1,5-methylene bridge synthesis -1H-3- benzazepine hydrochloride, which comprises the following Step: (1) 2-indanone of formula 3 and the compound and paraformaldehyde under alkaline or acidic conditions Mannich reaction, as shown in general formula 2 intermediate; (2) the step (I) obtained through reaction of Formula 2 intermediate under basic or acidic conditions by reducing the role of the carbonyl group is reduced to a methylene group, and get varenicline intermediate (II) by debenzylation, the reaction is:

Wherein, R groups are selected from _H, _Me, _Et, _iPr> _t_Bu.

Figure 2;

Wherein, R group is -H, -Me, -Et, -iPr or -t_Bu.

(2) Step (I) obtained by the reaction intermediates of formula under basic or acidic conditions by reducing the role of the carbonyl group is reduced 2 methylene, and get by debenzylation cutting Lenk Lin intermediate (II);

CLIP

Varenicline, a nicotinic 􀀁4􀀂2 partial agonist, was approved in the US for the treatment of smoking cessation in May of 2006. It was developed and marketed by Pfizer as a treatment for cigarette smokers who want to quit. Varenicline partially activates the nicotinic receptors and thus reduces the craving for cigarette that smokers feel when they try to quit smoking. By mitigating this craving and antagonizing nicotine activity without other symptoms, this novel drug helps quitting this dangerous addiction easier on the patients [6,52]. Several modifications [54,55] to the original synthesis [53,56] have been reported in the literature, including an improved process scale synthesis of the last few steps (Scheme 15) [57]. The Grignard reaction was initiated on a small scale by addition of 2-bromo fluorobenzene 113 to a slurry of Magnesium turnings and catalytic 1,2-dibromoethane in THF and heating the mixture until refluxing in maintained. To this refluxing mixture was added a mixture of the 2-bromo fluorobenzene 113 and cyclopentadiene 114 over a period of 1.5 h. After complete addition, the reaction was allowed to reflux for additional 1.5 h to give the Diels- Alder product 115 in 64% yield. Dihydroxylation of the olefin 115 by reacting with catalytic osmium tetraoxide in the presence of N-methylmorpholine N-oxide (NMO) in acetone: water mixture at room temperature provided the diol 116 in 89% yield. Oxidative cleavage of diol 116 with sodium periodate in biphasic mixture of water: DCE at 10ºC provided di-aldehyde 117 which was immediately reacted with benzyl amine in the presence of sodium acetoxyborohydride to give benzyl amine 118 in 85.7% yield. The removal of the benzyl group was effected by hydrogenation of the HCl salt in 40-50 psi hydrogen pressure with 20% Pd(OH)2 in methanol to give amine hydrochloride 119 in 88% yield. Treatment of amine 119 with trifluoroacetic anhydride and pyridine in dichloromethane at 0ºC gave trifluoroacetamide 120 in 94% yield. Dinitro compound 121 was prepared by addition of trifluoroacetamide 120 to a mixture of trifluoromethane sulfonic acid and nitric acid, which was premixed, in dichloromethane at 0ºC. Reduction of the dinitro compound 121 by hydrogenation at 40-50 psi hydrogen in the presence of catalytic 5%Pd/C in isopropanol:water mixture provided the diamine intermediate 122 which was quickly reacted with glyoxal in water at room temperature for 18h to give compound 123 in 85% overall yield. The trifluoroacetamide 123 was then hydrolyzed with 2 M sodium hydroxide in toluene at 37-40ºC for 2-3h followed by preparation of tartrate salt in methanol to furnish varenicline tartrate (XV).

[52]Keating, G.; Siddiqui, M. A. A. CNSdrugs, 2006, 11, 946.
[53] Coe, J. W.; Brooks, P. R.; Vetelino, M. G.; Wirtz, M. C.; Arnold,E. P. ; Huang, J.; Sands, S. B.; Davis, T. I.; Lebel, L. A.; Fox, C.
B.; Shrikhande, A.; Heym, J. H.; Schaeffer, E.; Rollema, H.; Lu,Y.; Mansbach, R. S.; Chambers, L. K.; Rovetti, C. C.; Schulz, D.
W.; Tingley, III, F. D.; O’Neill, B. T. J. Med. Chem., 2005, 48,3474.
[54] Brooks, P. R.; Caron, S.; Coe, J. W.; Ng, K. K.; Singer, R. A.;Vazquez, E.; Vetelino, M. G.; Watson, Jr. H. H.; Whritenour, D.
C.; Wirtz, M. C. Synthesis, 2004, 11, 1755.
[55] Singer, R. A.; McKinley, J. D.; Barbe, G.; Farlow, R. A. Org. Lett.,2004, 6, 2357.
[56] Coe, J. W.; Brooks, P. R. P. US-6410550 B1, 2002.
[57] Busch, F. R.; Hawkins, J. M.; Mustakis, L. G.; Sinay, T. G., Jr.;Watson, T. J. N.; Withbroe, G. J. WO-2006090236 A1, 2006.

PATENT

WO 2002085843

https://google.com/patents/WO2002085843A2?cl=en

PATENT

https://www.google.com/patents/EP2204369A1?cl=en

Varenicline (a compound I of formula I) is the international commonly accepted non-proprietary name for 7,8,9,10-tetrahydro-6,10-methano-6H-pyrazino[2,3-h][3]benzazepine (which is also known as 5,8,14-triazatetracyclo[10.3.1.0^2,11.0^4,9]-hexadeca-2(11),3,5,7,9-pentaene), and has an empirical formula of C₁₃H₁₃N₃ and a molecular weight of 211.26.

The L-tartrate salt of varenicline is known to be therapeutically useful and is commercially marketed for the treatment of smoking addiction. Varenicline L-tartrate is a partial agonist selective for α₄β₂ nicotinic acetylcholine receptor subtypes. In the United States, varenicline L-tartrate is marketed under the trade mark Chantix and is indicated as an aid to smoking cessation treatment.

Varenicline base and its pharmaceutically acceptable acid addition salts are described in U.S. Patent No. 6,410,550 . In particular, the preparation of varenicline provided in this reference makes use of 10-aza-tricyclo[6.3.1.0^2,7]-dodeca-2(7),3,5-triene (a compound of Formula VI), as a key intermediate compound (see Scheme 1 below). Specifically, Example 1 of U.S. Patent No. 6,410,550 describes the synthetic preparation of key intermediate compound of Formula VI as depicted in Scheme 1.

1,2,3,4-tetrahydro-1,4-methano-naphthalene-cis-2,3-diol (a compound of Formula III), and / or indane-1,3-dicarbaldehyde (a compound of Formula IV).

Example 1: Preparation of 1,2,3,4-tetrahydro-1,4-methano-naphthalene-cis-2,3-diol (a compound of Formula III)

A 10mL round bottom flask was charged with a compound of formula II (142mg, 1mmol), N-methylmorpholine-N-oxide (120mg, 1.03mmol), tert-butanol (3mL) and water (1mL). FibreCat^™ 3003 (OsO₄ anchored onto a polymeric support) (11.6mg, 0.0025mmol) was added to this solution and the mixture was heated to reflux. Complete conversion to a compound of formula III was detected by GC, method A, after 48h.

Example 2: Preparation of 1,2,3,4-tetrahydro-1,4-methano-naphthalene-cis-2,3-diol (a compound of Formula III)Step A) Preparation of hexadecyl-trimethylammoniumpermanganate (HTAP):

HTAP was prepared from ion exchange reaction between hexadecyltrimethylammoniumbromide and potassium permanganate.

Potassium permanganate (17.38g, 0.11mol, 1equiv.) was dissolved in 500mL water. A solution of hexadecyltrimethylammoniumbromide (40.10g, 0.11mol, 1equiv) in 500mL water was added drop-wise over 45 min at 20-22°C, and the mixture stirred for 30 minutes at this temperature. The precipitated solid was collected by filtration, washed with water (3 x 100mL) and dried under vacuum at 35°C for 24 hours to give 34.38g of HTAP as a light purple solid.

Step B) Preparation of a compound of formula III:

Compound II (3.52g, 24.8mmol, 1equiv.) was dissolved in anhydrous tetrahydrofuran (80mL) and a solution of HTAP (10g, 24.8mmol, 1.0equiv.) in anhydrous tetrahydrofuran (125mL) was added drop-wise at 23-30°C over 45min. The reaction was monitored by TLC (hexane-ethyl acetate = 1:1). After complete reaction the mixture was cooled to below 10°C, and methyl tert-butyl ether (50mL) and 5% aqueous NaOH solution (50mL) were added and the mixture stirred for 30min. The solid was removed by filtration, and washed with methyl tert-butyl ether (2 x 30mL). The combined layers of the filtrate were separated and the aqueous phase extracted with methyl tert-butyl ether (2 x 30mL). The organic layers were combined and washed with 5% aqueous NaOH solution (50mL), water (2 x 50mL), dried over MgSO₄, filtered and concentrated to obtain a dark green solid. This residue was suspended in acetone (15mL) and collected by filtration, washing with additional acetone (3 x 5mL). The product was dried under vacuum at 40°C to give 2.215g (50.7% yield) as a white crystalline solid.

Analytical data: m.p. = 178.8-179.3°C; ¹H-NMR: See Figure 1; ¹³C-NMR: See Figure 2.

Example 3: Preparation of indane-1,3-dicarbaldehyde (a compound of Formula IV)

A 25 mL round bottom flask was charged with a compound of formula I (142mg, 1mmol), Ruthenium (III) chloride hydrate (Aldrich, Reagent Plus^™) (7.2mg, 0.035mmol), acetonitrile (8.5mL) and water (1.1mL). The solution was heated to 45°C and sodium periodate (449mg, 2.1mmol) was added portionwise over 25 minutes. After 1h, the reaction was cooled to ambient temperature and filtered. The solids were washed with ethyl acetate (3 x 2mL) and water (3mL). The filtrate was concentrated under vacuum and 5mL of water were added to the obtained residue. The mixture was extracted with ethyl acetate (2 x 5mL) and the combination of the organic layers was washed with water (3 x 5mL), dried with MgSO₄ and concentrated under vacuum to obtain a compound of formula IV (118mg) in 68% yield, 70.9% purity (analyzed by GC, method A).

PATENT

WO 199935131, WO 2002092089, US 2013030179

PATENT

https://www.google.com/patents/WO2009065872A2?cl=en

Example 1: Preparation of 7,8,9,10- tetrahydro-6, 10-methano-6H-pyrazino [2, 3-h] [3] benzazepine L-tartrate (i.e. varenicline L-tartrate)

A) Preparation of compound of formula (III)

This example is based on U.S. Patent No. 6,410,550.

A 250 mL round bottom flask with thermometer, condenser, addition funnel and magnetic stirring was charged with 10-aza-tricyclo [ 6.3.1. O²‘⁷] dodeca-2, 4, 6- triene para-toluene sulfonic acid salt (12.4g, 37.5 mmol) and 44 mL of CH₂Cl₂. Triethylamine (8.3 g, 82.5 mmol) was added to the slurry and the resulting solution was cooled to 0-5 ⁰C. The addition funnel was charged with a solution of (CF₃CO)₂O (8.1q, 41.25 mmol) in 19 mL of CH₂Cl₂. This solution was slowly added to the reaction mixture, maintaining the temperature < 15 ⁰C. The resulting mixture was stirred for 1 hour, and the complete conversion was monitored by GC. The crude reaction mixture was washed with water (2 * 40 mL) and brine (40 mL) . The organic phase was used in the next step without further purification.

On the other hand, a 500 mL round bottom flask with thermometer, condenser, addition funnel and magnetic stirring was charged with CF₃SO₃H (25.9 g, 172.5 mmol), CH₂Cl₂ (110 mL) and cooled to 0-5 ⁰C. At this temperature, fuming nitric acid (5.4 g, 86.25 mmol) was added slowly. To the resulting slurry at 0-5 ⁰C, the solution obtained in the previous step was slowly added, maintaining the temperature < 15 ⁰C. After the addition, the reaction mixture was stirred overnight. The complete dinitration was confirmed by GC. The crude reaction mixture was poured into water (60 mL) an ice (80 g) and stirred. The phases were separated and the aqueous phase was extracted with CH₂Cl₂ (3 x 50 mL) . The mixture of the organic phases was washed with aqueous saturated NaHCO₃, dried over Na₂SO₄ and volatiles evaporated under vacuum to obtain 11.9 g of a solid that was suspended and stirred for 2 hours in AcOEt (12 mL) and hexanes (24 mL) . The solid was filtered and washed with hexanes to obtain the compound of formula (III), 9.1g with a purity of 88.9% by GC (9.8% of meta-dimtrocompound impurity) .