9-(5-Oxotetrahydrofuran-2-yl)nonanoic acid methyl ester

1H NMR

13C NMR

+

Cu

+

Operating scheme

Instructions

http://www.oc-praktikum.de/nop/en/instructions/pdf/4005_en.pdf

Instruction (batch scale 100 mmol)

Equipment 250 mL two-neck flask, protective gas supply, reflux condenser, heatable magnetic stirrer, magnetic stir bar, rotary evaporator, Buechner funnel, suction flask, desiccator, oil bath Substances undecenoic acid methyl ester (bp 248 °C) 19.8 g (22.3 mL, 100 mmol) iodoacetic acid ethyl ester (bp 73-74 °C/ 21 hPa) 27.8 g (15.4 mL, 130 mmol) copper powder (finely powdered, >230 mesh ASTM) 30.5 g (480 mmol) tert-butyl methyl ether (bp 55 °C) 130 mL petroleum ether (bp 60-80 °C) 300 mL Reaction In a 250 mL two-neck flask with magnetic stir bar and a reflux condenser connected with a protective gas piping 19.8 g (22.3 mL, 100 mmol) undecenoic acid methyl ester and 27.8 g (15.4 mL, 130 mmol) iodoacetic acid ethyl ester are mixed with 30.5 g (480 mmol) copper powder under a protective gas atmosphere. Afterwards the reaction mixture is stirred at 130 °C oil bath temperature under protective gas for 4 hours. (Reaction monitoring see Analytics.)

Work up The reaction mixture is cooled down to room temperature, 30 mL tert-butyl methyl ether are added, the mixture is stirred for 5 minutes and filtered off. The copper powder on the filter is washed four times with 25 mL tert-butyl methyl ether each. Filtrates and wash solutions are combined, the solvent is evaporated at the rotary evaporator. A yellow oil remains as crude product. Crude yield: 25.4 g.

The crude product is dissolved in 300 mL petroleum ether under reflux. The solution is allowed to cool down to room temperature, then it is stored in the refrigerator over night for complete crystallization. The crystalline product is sucked off over a Buechner funnel and dried in the vacuum desiccator. The mother liquor is stored again in the refrigerator for a check of complete crystallization. Yield: 19.5 g (76.1 mmol, 76%); white solid, mp 34 °C Comments In order to achieve a quantitative reaction within 4 hours, a fivefold excess of copper is used.

Waste management Recycling The copper powder can be used three times.

Waste disposal Waste Disposal evaporated tert-butyl methyl ether (might contain iodoethane) organic solvents, containing halogen mother liquor from recrystallization organic solvents, containing halogen copper powder solid waste, free from mercury, containing heavy metals

Time 6-7 hours

Break After heating and before recrystallizing

Degree of difficulty Easy

Analytics Reaction monitoring with TLC Sample preparation: Using a Pasteur pipette, two drops of the reaction mixture are taken and diluted with 0.5 mL diethyl ether. TLC-conditions: adsorbant: TLC-aluminium foil (silica gel 60) eluent: petroleum ether (60/80) : acetic acid ethyl ester = 7 : 3 visualisation: The TLC-aluminium foil is dipped in 2 N H2SO4 and then dried with a hot air dryer. Reaction monitoring with GC Sample preparation: Using a Pasteur pipette, one drop of the reaction mixture is taken and diluted with 10 mL dichloromethane. From this solution, 0.2 µL are injected. 10 mg from the solid product are dissolved in 10 mL dichloromethane. From this solution, 0.2 µL are injected. GC-conditions: column: DB-1, 28 m, internal diameter 0.32 mm, film 0.25 µm inlet: on-column-injection carrier gas: hydrogen (40 cm/s) oven: 90 °C (5 min), 10 °C/min to 240 °C (40 min) detector: FID, 270 °C Percent concentration was calculated from peak areas.

Educts		Amount	Risk	Safety
10-Undecenoic acid methyl ester		19.8 g	H- EUH-	P-
Iodoacetic acid ethyl ester	Danger	27.8 g	H300 H314 EUH-	P264 P280 P305 + 351 + 338 P310
Reagents		Amount	Risk	Safety
Copper powder	Warning	30.5 g	H400 EUH-	P273
Solvents		Amount	Risk	Safety
tert-Butyl methyl ether	Danger	130 mL	H225 H315	P210
Petroleum ether (60-80)	Danger	300 mL	H225 H304 H315 H336 H411 EUH-	P210 P261 P273 P301 + 310 P331
Others		Amount	Risk	Safety
Sulfuric acid 2N	Danger	H314 H290 EUH-	P280 P301 + 330 + 331 P305 + 351 + 338 P309 + 310
Solvents for analysis		Amount	Risk	Safety
Petroleum ether (60-80)	Danger	H225 H304 H315 H336 H411 EUH-	P210 P261 P273 P301 + 310 P331
Acetic acid ethyl ester	Danger	H225 H319 H336 EUH066	P210 P261 P305 + 351 + 338
Dichloromethane	Warning	H351 H315 H319 H335 H336 H373	P261 P281 P305 + 351 + 338

	two-necked flask 250 mL			protective gas piping
	reflux condenser			heatable magnetic stirrer with magnetic stir bar
	rotary evaporator			suction filter
	suction flask			exsiccator with drying agent
	oil bath

………………

………

 

////////////

Systematic (IUPAC) name
(3S)-2-[(2S)-2-{[(2S)-1-ethoxy-1-oxo-4-phenylbutan-2-yl]amino}propanoyl]-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid
Clinical data
Trade names	Univasc
AHFS/Drugs.com	monograph
MedlinePlus	a695018
Pregnancy category	US: D (Evidence of risk)
Legal status	UK: Prescription-only (POM) US: ℞-only
Routes of administration	Oral
Pharmacokinetic data
Bioavailability	13-22%
Protein binding	90%
Metabolism	Hepatic (active metabolite, moexiprilat)
Biological half-life	1 hour; 2-9 hours (active metabolite)
Excretion	50% (faeces), 13% (urine)
Identifiers
CAS Registry Number	103775-10-6
ATC code	C09AA13
PubChem	CID: 91270
IUPHAR/BPS	6571
DrugBank	DB00691
ChemSpider	82418
UNII	WT87C52TJZ
KEGG	D08225
ChEMBL	CHEMBL1165
Chemical data
Formula	C27H34N2O7
Molecular mass	498.568 g/mol

Necessity of Establishing Chemical Integrity of Polymorphs of Drug Substance Using a Combination of NMR, HPLC, Elemental Analysis, and Solid-State Characterization Techniques: Case Studies

Pemirolast (INN) is a mast cell stabilizer used as an anti-allergic drug therapy. It is marketed under the tradenames Alegysal and Alamast.

9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido-[1, 2-a]-pyrimidin-4-one

It has also been studied for the treatment of asthma.

https://www.google.com/patents/US9006431

Pemirolast is an orally-active anti-allergic drug which is used in the treatment of conditions such as asthma, allergic rhinitis and conjunctivitis. See, for example, U.S. Pat. No. 4,122,274, European Patent Applications EP 316 174 and EP 1 285 921, Yanagihara et al, Japanese Journal of Pharmacology, 51, 93 (1989) and Drugs of Today, 28, 29 (1992). The drug is presently marketed in e.g. Japan as the potassium salt under the trademark ALEGYSAL™.

Commercial pemirolast potassium has the disadvantage that it is known to give rise to sharp plasma concentration peaks in humans (see, for example, Kinbara et al, “Plasma Level and Urinary Excretion of TBX in Humans”, Japanese Pharmacology & Therapeutics, 18(3) (1990), and “Antiallergic agent—ALEGYSAL tablet 5 mg—ALEGYSAL tablet 10 mg—ALEGYSAL dry syrup”, Pharmaceutical Interview Form (IF), Revised in October 2007 (7th version), Standard Commodity Classification No.: 87449). The latter document also reports that the potassium salt of pemirolast is hygroscopic, which is believed to give rise to chemical instability, and possesses a bitter taste.

U.S. Pat. No. 4,122,274 describes a process for the production of salts of pemirolast, including potassium salts and (at Example 14) a sodium salt. As described herein, this technique produces a sodium salt that is physically unstable. Sodium salts of pemirolast are also mentioned (but a synthesis thereof not described) in international patent applications WO 2008/074975 and WO 2008/075028.

COMPARATIVE EXAMPLE 5Recrystallisation of Pemirolast Sodium According to the Method of U.S. Pat. No. 4,122,274

In U.S. Pat. No. 4,122,274, it is stated that the crude title product (pemirolast sodium) was recrystallised from water:ethanol to give pure title product. It is not clear from this level of detail what the ratio of water:ethanol employed was, so several experiments were performed with a view to reproducing the prior art technique.

• (i) Crude sodium salt of pemirolast (480 mg; from Example 4, method (I) above) was recrystallised from water and ethanol (95%) in a 1:1 ratio. The Na salt of pemirolast (480 mg, 1.92 mmol) was dissolved in H₂O (8 mL) at 70° C. and EtOH 95% (8 mL) was added. The clear solution was allowed to reach room temperature and the solid material formed was filtered off, washed with a small amount of ethanol and dried in vacuum to give 316 mg of pure sodium salt.
• (ii) Crude sodium salt of pemirolast (500 mg; from Example 4, method (II) above) was dissolved in water (4.9 mL) at 70° C. Thereafter EtOH 95% (ca. 4.0 mL) was added at 70° C. until a solid started to form. Another 0.1 mL of water was added to get everything into solution. The solid material formed upon cooling was collected by filtration and dried under vacuum to give 348 mg of pure sodium salt.
• (iii) Crude sodium salt of pemirolast (300 mg; from Example 4, method (II) above) was recrystallised from water:ethanol (1:1 ratio; 10 mL) at 70° C. The solid material formed upon cooling was collected by filtration and dried under vacuum to give 174 mg of pure sodium salt.
• (iv) Crude sodium salt of pemirolast (300 mg; from Example 4, method (II) above) was recrystallised from water:ethanol (9:1 ratio, 4 mL) at 70° C. The solid material formed upon cooling was collected by filtration and dried under vacuum to give 219 mg of pure sodium salt.

All four samples of pure pemirolast sodium salt had the same physico-chemical properties (Raman spectra and NMR):

¹H NMR (D₂O) δ: 8.86-8.80 (m, 1H, CH), 8.57 (s, 1H, CH), 7.68-7.59 (m, 1H, CH), 7.22-7.13 (m, 1H, CH), 2.39 (s, 3H, CH₃).

The PXRD pattern (measured in respect of Example 5(i) above) is shown in FIG. 3. It was concluded from this that this form of the sodium salt is an amorphous material mixed with a crystalline fraction.

The Raman spectrum was recorded directly after recrystallisation. All samples were then stored under ambient conditions on a shelf in a fume hood. About a month later, a Raman spectrum was recorded, which was significantly different to that recorded earlier. This is shown in FIG. 4, where the lower spectrum accords to the earlier measurement and the upper spectrum accords to the later measurement. In the light of these results, it was concluded that the prior art amorphous form of pemirolast sodium is physically unstable.

The amorphous material was also prepared by drying of the form obtained in accordance with Example 11 below at 40° C. and reduced pressure for 40 hours to yield 12 g of a pale yellow cotton-like amorphous solid.

………………………..

http://www.lookchem.com/Chempedia/Chemical-Technology/Organic-Chemical-Technology/18815.html

1) Firstly, 2-Amino-3-methylpyridine (I) is condensed with ethoxymethylenemalonodinitrile (II) to afford the monocyclic intermediate (III), which is in tautomeric equilibrium with the pyridopyrimidine derivative (IV). Next, the reaction of (IV) with aluminum azide (AlCl₃.NaN₃) in refluxing THF yields 4-imino-9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidine (V). Finally, this compound is first hydrolyzed with 1N HCl and then treated with KOH.
2) Compound (IV) can be converted to the final product by a one-pot reaction: (VI) is treated first with NaN₃ in refluxing acetic acid, then hydrolyzed with HCl and finally treated with KOH.

………….

EXAMPLE 1

A suspension of 9-methyl-3-(1 H-tetrazol-5-yl)-4H-pyrido-[1,2-a]-pyrimidin-4-one (68.5 g; 0.3 mols) in methanol (420 ml) and water (210 ml) heated at 50° C. is added with a 40% N-methylamine aqueous solution (30 ml, 0.35 mols) to pH=10. The solution is heated at 68-70° C., and acidified with formic acid (21 ml) to pH=3. After completion of the addition the mixture is kept at 68-70° C. for about 15 minutes and then cooled to 20-25° C. The precipitate is filtered, washed with methanol and dried under vacuum at 40° C. to give 9-methyl-3-(1 H-tetrazol-5-yl)-4H-pyrido-[1,2-a]-pyrimidin-4-one with >99.8% HPLC purity (63 g, 92% yield).

EXAMPLE 2

9-Methyl-3-(1 H-tetrazol-5-yl)-4H-pyrido-[1,2-a]-pyrimidin-4-one (63 g, 0.28 mols) is suspended in methanol (1000 ml). The resulting suspension is kept at 45° C. and slowly added with a 45% potassium hydroxide aqueous solution to pH 9-9.5. The suspension is stirred at 45° C. for about 15 minutes and then cooled to 20° C. The precipitate is filtered, washed with methanol and dried under vacuum at 80° C., to obtain Pemirolast Potassium (71.9 g; 0.27 mols, 96% yield) with HPLC purity >99.8%. ¹H NMR(D₂O, TMS) d (ppm): 2.02 (s, 3H); 6.83 (t, 1H); 7.22 (d, 1H); 8.18 (s, 1H); 8.47 (d, 1H).

References

• Tinkelman DG, Berkowitz RB (February 1991). “A pilot study of pemirolast in patients with seasonal allergic rhinitis”. Ann Allergy 66 (2): 162–5. PMID 1994787.
• Kawashima T, Iwamoto I, Nakagawa N, Tomioka H, Yoshida S (1994). “Inhibitory effect of pemirolast, a novel antiallergic drug, on leukotriene C4 and granule protein release from human eosinophils”. Int. Arch. Allergy Immunol. 103 (4): 405–9. doi:10.1159/000236662. PMID 8130655.
• Abelson MB, Berdy GJ, Mundorf T, Amdahl LD, Graves AL (October 2002). “Pemirolast potassium 0.1% ophthalmic solution is an effective treatment for allergic conjunctivitis: a pooled analysis of two prospective, randomized, double-masked, placebo-controlled, phase III studies”. J Ocul Pharmacol Ther 18 (5): 475–88. doi:10.1089/10807680260362759. PMID 12419098.
• Kemp JP, Bernstein IL, Bierman CW et al. (June 1992). “Pemirolast, a new oral nonbronchodilator drug for chronic asthma”. Ann Allergy 68 (6): 488–91. PMID 1610024.

Pemirolast

Systematic (IUPAC) name
9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1,2-a]pyrimidin-4-one
Clinical data
Trade names	Alamast
AHFS/Drugs.com	monograph
Pregnancy category	US: C (Risk not ruled out)
Legal status	℞ (Prescription only)
Routes of administration	Oral, ophthalmic
Identifiers
CAS Registry Number	69372-19-6
ATC code	None
PubChem	CID: 57697
IUPHAR/BPS	7329
DrugBank	DB00885
ChemSpider	51990
UNII	2C09NV773M
KEGG	D07476
ChEMBL	CHEMBL1201198
Chemical data
Formula	C10H8N6O
Molecular mass	228.21 g/mol

Pemirolast Potassium (BMY 26517) cas100299-08-9is a histamine H1 antagonist and mast cell stabilizer that acts as an antiallergic agent.
Target: Histamine H1 Receptor
Pemirolast potassium (BMY 26517) is a new oral, nonbronchodilator antiallergy medication that is being evaluated for the therapy of asthma [1]. Pemirolast potassium (BMY 26517) inhibits chemical mediator release from tissue mast cells and is also shown to inhibit the release of peptides including substance P, Pemirolast potassium (BMY 26517) reduces kaolin intake by inhibition of substance P release in rats [2]. Pemirolast potently attenuates paclitaxel hypersensitivity reactions through inhibition of the release of sensory neuropeptides in rats [3]. Pemirolast potassium is used for the treatment of allergic conjunctivitis and prophylaxis for pulmonary hypersensitivity reactions to drugs such as paclitaxel [4].

Molecular formula: C₁₀H₇KN₆O

Molecular Weight: 266.30

External links

• Mitsubishi Tanabe Pharma Corporation (2007). “ALEGYSAL (English)” (PDF). Retrieved 2008-09-02.
• “DailyMed Announcements”. U.S. National Library of Medicine. 2005. Retrieved 2008-09-02.

The goals of process optimization change with the successful development of a project from early process research through scale-up into dedicated manufacturing. This general order of optimization may differ according to the nature of the process being considered; for instance, a process generating an inordinate amount of waste may be optimized to decrease waste before scaling up to the pilot plant. The initial goal of all process research and development is to maximize the amount of product generated under the reaction conditions. This is done by driving the reaction to completion, that is, by consuming any starting material that is charged in limiting amounts and by generating product with a minimal amount of by-products. Once the in-process yield has been optimized, the maximum yield of isolated product is expected. Rapid optimization is possible by judiciously changing solvents, reagents, catalysts, and ligands; investigations in this area allow the chemist considerable room for creativity and simplifying a process. Such changes may generate different impurities in the isolated intermediates, and it may be necessary to examine the tolerance of subsequent processes for the new impurities.

• Foreword by K. Barry Sharpless
• Foreword by Jerome L. Moniot

• Preface

• About the Author

• Chapter 1 – Approaches to Process Development

• Chapter 2 – Route Selection

• Chapter 3 – Reagent Selection

• Chapter 4 – Solvent Selection

• Chapter 5 – Running the Reaction

• Chapter 6 – Effects of Water

• Chapter 7 – In-Process Controls

• Chapter 8 – Optimizing the Reaction by Minimizing Impurities

• Chapter 9 – Optimizing Catalytic Reactions

• Chapter 10 – Work-up

• Chapter 11 – Tools for Purifying the Product: Column Chromatography, Crystallization and Reslurrying

• Chapter 12 – Final Product Form and Impurity Considerations

• Chapter 13 – Vessels and Mixing

• Chapter 14 – Preparing for and Implementing the Scale-up Run

• Chapter 15 – Troubleshooting

• Chapter 16 – Chiral Syntheses

• General Index

• Reaction Type Index

• Reagent Index

  Neal G. Anderson, PhD

  For the past 17 years Neal has consulted to the pharmaceutical and fine chemical industries on chemical process research and development. He has presented short courses internationally on process R&D for “small molecules” to over 1400 participants from more than 160 companies. Keys to efficient scale-up are anticipating and then avoiding diffiulcties. Prior to consulting he worked at Bristol-Myers Squibb for 17 years. During that time, he had extensive hands-on experience with chemical process R&D in the lab, pilot plant, and manufacturing sites, including 12 manufacturing start-ups and process development for four major drugs. He is the author of Practical Process Research & Development(Academic Press; 2nd edition 2012).

  Education & Training

  • 1977-1979, post-doctoral studies, McNeil Laboratories
  • 1977, Ph.D., Medicinal Chemistry, University of Michigan
  • 1972, B.Sc., Honors Biology, University of Illinois

   

I consult to the pharmaceutical and fine chemical industries on developing and trouble-shooting processes to efficiently prepare drug substances and intermediates on large scale.  Anticipating and avoiding problems are key for effective and efficient scale-up.  For 17 years I have been consulting and presenting short courses internationally on process chemistry R & D for “small molecules” (over 1400 participants from more than 160 companies).  Prior to consulting I worked at Bristol-Myers Squibb for 17 years.  During that time I had extensive hands-on experience with chemical process development in the lab, pilot plant, and manufacturing sites, including 12 manufacturing start-ups and process development for four major drugs and many new drug candidates.  I wrote Practical Process Research & Development (Academic Press, 2000; 2nd edition 2012).

Practical Process Research & Development describes the development of chemical processes for the pharmaceutical and fine chemicals industries.  It provides a comprehensive, step-by-step approach to process R & D, and it is designed for those who want insights into generating rugged, practical, cost-effective processes.  Guidelines for industrial process R & D are rarely taught in academia, although this book has been used as a textbook.  It is primarily used by those in industry.

The second edition updates the first edition and includes topics not covered in the first edition, such as genotoxins, biocatalysis, green solvents, predicting effective solvent combinations, and process validation.  Almost 85% of the references cited were published after the first edition was published, and virtually all examples in the Figures are new.  Trevor Laird kindly wrote a forward for this edition.

The second edition has been translated into Japanese and graced with a handsome cover.  Noriaki Murase was the translation supervisor, and the translators were Shohei Imachi, Koreaki Imura, Dai Tatsuta, Taro Tsukude, Toyoharu Numata, Yujiro Furuya, Akira Manaka, and Noriaki Murase. Sayaka Nukatsuka was the editor. I am very grateful to these people for their hard work to translate my book.

I am grateful to Barry Sharpless and Jerry Moniot for writing forwards to the first edition  I am also grateful to the following people for their translations of the first edition of my book.  Noriaki Murase, Yoshinori Murata, Toyoharu Numata, Mio Sakai, and Tatsuo Ueki translated Practical Process Research & Development into Japanese.  Kwang-Hyun Ahn, Yeung-Ho Park, and Sung-Kwan Hwang  translated Practical Process Research & Development into Korean.  Zhinong Gao and Wenhao Hu translated Practical Process Research & Development into Chinese.

free look

Efforts toward the synthesis and process optimization of boceprevir 1 are described. Boceprevir synthesis was optimized by telescoping the first three steps and last two steps of the five-step process. Optimization of oxidation, which is one of the critical steps in the total synthesis, is discussed. A control strategy for the three impurities is described. A novel process for the synthesis of fragment A (2) has been developed, which is the key starting material for the synthesis of boceprevir.

…………………

WO 2015004685

( 1 R,5S)-N-[3-Amino- 1 -(cyclobutylmethyl)-2,3-dioxopropyl]-3-[2(S)-[[[( 1 , 1 -dimethylethyl) amino]carbonyl]amino]-3,3-dimethyl-l-oxobutyl]-6,6-dimethyl-3-azabicyclo [3.1.0]hexan-2(S)-carboxamide (Boceprevir); having formula I. It is a hepatitis C virus (“HCV”) protease inhibitor, developed by Merck & Co and marketed under the brand name of VICTRELIS.

Formula I

U.S. patent number 6,992,220, U.S. patent application numbers 201 1034705, U.S. 20050249702 and U.S. 201001 13821 are disclosed process for the preparation of Boceprevir.

U.S. patent number 7,326,795 claims Boceprevir bisulfate adduct as a product. Advanced Organic Chemistry, 4th ed., Jerry March Ed., John Wiley and Sons, 1972 disclosed purification methods from bisulfate adduct to provide the compound in a pure form.

U.S. patent number 8,222,427 claims a process for the purification of Boceprevir through a corresponding bisulfite adduct, wherein the compound of Formula I is dissolved in organic solvent, which is treated with an aqueous phase comprising bisulfite, thereby forming an aqueous solution of the bisulfite adduct of the compound of Formula I, which is subsequently regenerated from the aqueous phase without isolating the bisulfite adduct.

Examples:

Example 1:

183.7 gm of l-Dimethylaminopropyl-3-ethylcarbodiimide hydrochloride and 500 ml of dimethylsulfoxide were taken at 23-25 °C and to this 500 ml of ethyl acetate was added then cooled to 2-8 °C. 3-[2-(3-Tert-butylureido)-3,3-dimethyl-butyryl]-6,6-dimethyl-3-azabicyclo[3.1.0] hexane-2 carboxylic acid(2-carbamoyl-l-cyclobutyl-(methyl-2-hydroxy-ethyl)amide (Hydroxy Boceprevir) 100 gm was added to the reaction mixture under stirring at same temperature followed by 86.5 gm of dichloroacetic acid and continued stirring for 1-2 hrs. After completion of the reaction, 2500 mL of water was added to the reaction mixture at 2-10 °C and the reaction mixture temperature was raised to 15-20 °C. Ethyl acetate 600 ml was added to the reaction mass and the organic layer was separated. The product was extracted from aqueous layer with ethyl acetate. The organic layer was washed with 5% w/w hydrochloric acid followed by water. To the organic layer, aqueous solution of sodium bisulfite (300 gm in 600 ml) was added and stirred for 2 hrs. The layers were separated and organic layer was extracted with water. Thereafter, extracted aqueous layer was washed with ethyl acetate. To the aqueous layer sodium bisulfite (5.1 gm in 17 ml of water) was added and stirred for 30 min. The obtained solution was degassed and the pH was adjusted to 1.0 to 2.5 with dilute hydrochloric acid (15 ml of 35% w/w hydrochloric acid and 15 ml of water) and cooled to 10-15 °C. The obtained solid was filtered and washed with water to yield pure Boceprevir.

Exam le 2:

202 gm of l-Dimethylaminopropyl-3-ethylcarbodiimide hydrochloride and 500 ml of dimethylsulfoxide were taken at 23-25 °C and stirred, to this reaction mixture 500 ml of ethyl acetate was added; stirred and cooled to 2-8 °C. Hydroxy Boceprevir 100 gm was added under stirring at same temperature followed by 92.7 gm of dichloroacetic acid and continued stirring for 2-4 hrs. After completion of the reaction, 2500 mL of water was added to the reaction mixture at 2-10 °C and temperature was raised to 20-25 °C. Ethyl acetate 600 ml was added to the reaction mass and the organic layer was separated. The product was extracted from aqueous layer with ethyl acetate. The both organic layers were combined and stirred with dilute hydrochloric acid solution (prepared by mixing 50 ml of ~35% w/w of hydrochloric acid and 950 mL of water). The organic layer containing the product was separated and washed with water. The organic layer was cooled to 1-5 °C. To the organic layer, aqueous solution of sodium bisulfite (300 gm in 600 ml) was added and stirred for 2 hrs at 5- 9 °C. The organic layer was cooled without agitation and added precooled water at 5-10 °C. The aqueous layer containing the product was collected. The aqueous layer filtered through hyflo and washed with precooled water. Further the aqueous layer was diluted with precooled water, and adjusted the pH to 2 – 2.8 with dilute hydrochloric acid. Vacuum was applied to the aqueous layer and the temperature was slowly raised to less than 23 °C under reduced pressure. The separated solid was filtered at 22-30 °C and washed with water. Further, the filtered solid was washed with water having pH 1.8-2.4 (The pH of the water was adjusted with HC1). The product was dried at 24-28 °C under reduced pressure to yield pure Boceprevir.

Example 7:

100 gm of Crude Boceprevir was added to 300 mL of ethanol-isopropyl alcohol (1 : 1) at 22-30 °C and contents were stirred for about 40 minutes. The resulting solution was added to water slowly at 5-10 °C and stirred for 2-4 hrs at the same temperature. The product was filtered, washed with water and dried at 25-30°C under reduced pressure.

…………………

SCHERING CORPORATION Patent: WO2008/76316 A2, 2008 ; Location in patent: Page/Page column 27 ;

or eq https://www.google.co.in/patents/EP2121604A2?cl=en

Hepatitis C virus (HCV) is a (+)-sense single-stranded RNA virus that has been implicated as the major causative agent in non-A, non-B hepatitis; an HCV protease necessary for polypeptide processing and viral replication has been identified. U.S. Patent No. 7,012,066 discloses a genus of HCV protease inhibitor compounds that includes the compound of Formula I, (1 R,5S)-N-[3-amino-1-(cyclobutylmethyl)-2,3- dioxopropyl]-3-[2(S)-[[[(1 , 1 -dimethylethyl)amino]-carbonyl]amino]-3,3-dimethyl-1 – oxobutyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexan-2(S)-carboxamide.

Formula I

US2005/0059800, published March 17, 2005, discloses a process for preparing the compound of Formula I and discloses a bisulfite adduct of Formula I which can be used to provide the compound in a pure form in accordance with the methods taught in Advanced Organic Chemistry, 4^th ed., Jerry March Ed., John Wiley and Sons, 1972.

US2005/0020689, filed January 27, 2005, discloses processes for preparing an intermediate useful in preparing the compound of Formula I. Methods for preparing diastereomers of the compound of Formula I are disclosed in US2005/0249702, filed November 10, 2005. Published US Patent Application No. 2007/0149459, filed November 13, 2006, discloses oxidation processes for preparing the compound of Formula I.

Purification of the compound of Formula I is difficult for several reasons. The compound Formula I is an alpha-keto amide that is unstable and forms dimers, especially under basic conditions. Also, the compound of Formula I is amorphous, thus it does not crystallize and precipitation does not improve the purity of the solid —

Previously published procedures for preparing the compound of Formula I resulted in about 63 to about 98.5% purity.

Historically, aldehydes and ketones have been purified by preparing their bisulfite adduct. Bisulfite purification of these types of compounds was performed through isolation of a solid bisulfite adduct intermediate from aqueous alcoholic solution by filtration. Regeneration of an aldehyde or ketone from an isolated bisulfite adduct is accomplished using a base or a strong acid. Examples appearing in the literature of regeneration using bases includes: Na₂Cθ₃ in Org. Synthesis Coll. Vol. 4, 903 (1963); NaOH in WO 2006/074270 A2; and K₂CO₃ in Tetrahedron Lett., 45, 3219 (2004). Examples of regeneration using acids include: H₂SO₄ in J. Am. Chem. Soc, 70, 1748 (1948); and HCI in WO 99/57123.

For the preparation of a purified product, isolation of an intermediate solid bisulfite adduct is not preferred since filtration of the adduct is required. In addition, base regeneration of the adduct to yield the substrate is not appropriate in those cases wherein the regenerated product is unstable in basic conditions, for example, where the regenerated product is the compound of Formula I. When acid conditions are used to regenerate the substrate compound from a bisulfite adduct, generally strongly acidic conditions and heating are necessary (see references above).

Published international application no. WO 99/57123 reports using non- alcoholic solvent in a process for forming a bisulfite adduct, however the process required isolation of a solid bisulfite adduct and regeneration the substrate from the adduct using NaOH.

A non-aqueous method for regeneration of a substrate from the corresponding bisulfite adduct was reported in J. Org. Chem., 64, 5722 (1999) as a means to overcome side-reactions such as degradation and hydrolysis during regeneration of aldehyde/ketone with a base or an acid. In this method, trimethylsilyl chloride (TMSCI) or its equivalent was employed in acetonitrile. During the process TMS₂O, NaCI₁ SO₂ and HCI were generated as co-products when TMSCI was used.

Removal of the co-products required the process steps of filtration (for NaCI), aqueous work-up (for NaCI and excess TMSCI) and distillation (for TMS₂O), which requires use of a high boiling solvent. Regeneration of aldehydes from the corresponding bisulfite adducts with ammonium acetate in solvent-free conditions was reported in J. of Chem. Research, 237 (2004), however this process requires microwave irradiation.

Published international application no. WO 2006/076415 describes regeneration of an aldehyde from a corresponding bisulfite adduct isolated from an alcoholic solvent system using a carbonate base with a lower alkyl carbonyl compound, for example, acetone and glyoxylic acid.

SCHEME Il

solv

Bisulfite Adduct

Formula I in water Formula I

SCHEME III

Formula I

Published U.S. patent application no. 2007/0149459, published June 28, 2007, discloses several alternate procedures for oxidizing the intermediate compound of the Formula II:

Formula II, to obtain the compound of Formula I.

HPLC Determination of Purity

The purity of the compound of Formula I is determined by HPLC according to the methods described below:

alternatively, the following equipment and conditions are used:

Example 1

(Purification Process of Scheme III, Regeneration Option “a”)

Preparation of Compound: To a reactor was charged (16.5 kg) of the compound of Formula II,

Formula Il24.3 Kg of EDCI₁ and 190 L of EtOAc. The batch temperature was adjusted between 15 and 25⁰C. At the same temperature, Et₃N (9.60 kg, 3 eq) followed by EtOAc rinse (8 L) was charged. To the resultant mixture was charged DMSO (83 L) while maintaining the temperature of the batch between 15⁰C and 25⁰C. CH₃SO₃H (10.89 kg) was charged while maintaining the reaction mixture between 15⁰C and 30° C. After agitating at the reaction mixture for 1.5 hours while maintaining the reaction mixture between 20⁰C and 30⁰C, the reaction mixture was cooled to a temperature between -5⁰C and 5⁰C.

Purification of the Compound of Formula I

In a separate reactor was charged 165 L of water and 33 L of EtOAc, and the mixture was cooled below 5⁰C. The reaction mixture containing the compound was transferred into the mixture of cold water/EtOAc at 0 to 10⁰C. The organic layer was separated and washed with water (99 L) three times. Step 1 : To the resulting organic solution was added NaHSθ3 aqueous solution

(prepared from 49.5 kg of NaHSO₃ and 109 L of water). The whole was agitated for 3 h at 20-30⁰C. The aqueous NaHSO₃ layer was separated and saved. The organic layer was concentrated to about 116 L of volume and diluted with MTBE (220 L). The separated aqueous NaHSO₃ layer was added to the organic layer. The resultant mixture was agitated for 3 h at 20-30 ⁰C. The organic layer was separated and cooled to 0-10 ⁰C.

Step 2: To the cooled organic layer of Step 1 was added cold water (165 L, 0-10⁰C) without agitation, and the whole was agitated for 5 min. The aqueous layer was separated, and a solution of water (2 L) containing NaHSO₃ (0.71 kg) was added to the water layer. The water layer was distilled to the final volume of about 171 L under vacuum below 25 ⁰C to remove volatiles.

Step 3: (Regeneration method a): The resultant water layer of Step 2 was added into a slurry of NaCI (49.5 kg) in acetone (83 L) at 20-30⁰C. The separated acetone layer followed by acetone rinse (8 L) was added through a 0.2 micron filter to water (347 L) over 20 min at 15-25 ⁰C. After agitation for about 1 h, the precipitate was filtered and washed with water (83 L). The wet cake was dried under vacuum at 30-40⁰C to produce 13.0 kg (79%) of the purified compound as a white solid.

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US2007/149459

http://www.google.co.in/patents/US20070149459

EXAMPLESPreparation of (1R,2S,5S)-N-[3-amino-1-(cyclobutylmethyl)-2,3-dioxopropyl]-3-{N-[(tert-butylamino)carbonyl]-3-methyl-L-valyl}-6,6-dimethyl-3-azabicyclo-[3.1.0]hexane-2-carboxamide (the Compound of Structure 2 in Scheme A, Below)

Example 1Preparation of Compound 2 Using Aqueous Acetic Acid in the Reaction Mixture

Into a 1 L, three necked flask is placed KBr (10 g, 84 mmol), NaOAc (10 g, 122 mmol), Compound 1 (50 g, 96 mmol), and TEMPO (15 g, 96 mmol), followed by 500 mL of MTBE. The reaction mixture is stirred at 350-400 rpm and the temperature is maintained at a temperature of from 10° C. to 20° C. Acetic acid (50 mL, 874 mmol), and water (5 mL) are added to the reaction mixture and the two phase mixture is agitated for 15 minutes. Continuously, over a two hour period, to the reaction mixture is added 158 mL of a 0.82 M solution of NaOCl (130 mmol). When all of the NaOCl solution is added, the reaction mixture is stirred for an additional 3 hours while maintaining the temperature. Water (50 mL) is added.

The layers are separated and the organic layer is washed twice with water (2×250 mL). A solution of ascorbic acid, which is prepared from 50 g of sodium ascorbate, 200 mL of water, and 50 mL of 4N HCl, is added to the organic layer and the mixture is stirred for about 1 hour. After the layers are separated, the organic layer is washed twice with water (2×250 mL). The organic layer is concentrated by distilling off solvent at low temperature (0-5° C.) until the total volume is about 350 mL. The concentrated organic layer is added dropwise over 30 minutes into a 3 L flask containing 2 L of n-heptane at about 0° C. providing a white precipitate. The white precipitate is collected by filtration, washed with n-heptane (400 mL) and dried in a vacuum oven (2 hr at 25° C., 8 hr at 350, and 8° C. at 45° C.). The product is obtained as a white powder (typically 94-96% yield).

¹H NMR, δ 0.84 (d, J=2.3 Hz, 3H), 0.90-1.02 (m, 9H), 0.99 (d, J=4.0 Hz, 3H), 1.24 (s, 9H), 1.40-1.86 (m, 7H), 1.90-2.10 (m, 3H), 2.25-2.40 (m, 1H), 3.75 (dd, J=5.3 and 10.4 Hz, 1H), 4.10 (dd, J=6.8 and 10.4 Hz, 1H), 4.4 (dd, J=3.0 and 5.3 Hz, 2H), 5.17 (dddd, J=4.6, 8.1, 8.1, and 10.4 Hz, 1H), 5.3 (br s, 2H), 6.71 (d, J=14.7 Hz, 1H), 6.90 (dd, J=2.3 and 19.0 Hz, 1H), and 7.34 (dd, J=7.1 and 20.2 Hz, 1H).

Example 2Preparation of Compound 2 Using Glacial Acetic Acid in the Reaction Mixture

Into a 2 L, three necked flask was charged KBr (20 g, 168 mmol), NaOAc (20 g, 243 mmol), Compound 1 (100 g, 192 mmol), and TEMPO (30 g, 192 mmol), followed by 800 mL of MTBE. The reaction mixture was stirred at 350400 rpm while the temperature of the reaction mixture was maintained at a temperature of from 10° C. to 20° C. Acetic acid (70 mL, 1223 mmol, used as received), was added and the mixture was agitated for 15 minutes additional. Continuously, over a two hour period, 315 ml of a 0.73M solution of NaOCl (230 mmol) was added to the reaction mixture. When all of the NaOCl solution had been added, agitation was continued for an additional 3 hours. Water (100 mL) was added to the reaction mixture at the end of 3 hours. The layers were separated and the organic layer was washed once with water (500 mL).

A solution of ascorbic acid, which was prepared from 100 g of sodium ascorbate, 456 mL of water, and 44 mL of 36% HCl, was added to the organic layer and the mixture was stirred for about 2 hours. The layers were separated and then a solution of 3.5N HCL was added and stirred about 30 minutes. After the layers were separated, the organic layer was washed three times with water (3×500 mL). This organic layer was then added drop-wise over 30 minutes into a 5 L flask containing 3 L of n-heptane at about −10 to about 0° C. The white precipitate was filtered, washed with n-heptane (600 mL) and dried in a vacuum oven (2 hr at 25° C., 8 hr at 350, and 8° C. at 45° C.). The product was obtained as a white powder (93% yield).

¹H NMR, δ 0.84 (d, J=2.3 Hz, 3H), 0.90-1.02 (m, 9H), 0.99 (d, J=4.0 Hz, 3H), 1.24 (s, 9H), 1.40-1.86 (m, 7H), 1.90-2.10 (m, 3H), 2.25-2.40 (m, 1H), 3.75 (dd, J=5.3 and 10.4 Hz, 1H), 4.10 (dd, J=6.8 and 10.4 Hz, 1H), 4.4 (dd, J=3.0 and 5.3 Hz, 2H), 5.17 (dddd, J=4.6, 8.1, 8.1, and 10.4 Hz, 1H), 5.3 (br s, 2H), 6.71 (d, J=14.7 Hz, 1H), 6.90 (dd, J=2.3 and 19.0 Hz, 1H), and 7.34 (dd, J=7.1 and 20.2 Hz, 1H).

Boceprevir

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Chinese journal of medicinal chemistry 2011, 21, 5 , pg 409-10

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J Med Chem,2006,49(20):6074-6086.

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WO2004/113294 A1

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MSN LABORATORIES LIMITED; THIRUMALAI RAJAN, Srinivasan; ESWARAIAH, Sajja; VENKAT REDDY, Ghojala; SAHADEVA REDDY, Maramreddy Patent: WO2014/61034 A1, 2014 ;

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WO2013066734A1

MERCK SHARP and DOHME CORP.; WU, George, G.; ITOH, Tetsuji; MCLAUGHLIN, Mark; LIU, Zhijian; QIAN, Gang Patent: WO2013/66734 A1, 2013 ;

Example 1: Cyclobutylacetonitrile

Step 1 : Cyclobutylmethyl methanesulfonate

A 50-L jacket vessel was charged with DCM (20 L) (KF 34 ppm), and cyclobutylmethyl alcohol (5.0 kg, 58.0 mol) followed by TEA (8850 mL, 63.5 mol). The reaction mixture was cooled to approximately -10°C, and MsCl (4735 mL, 60.8 mol) was added via an addition funnel dropwise over approximately 3 hours, while the temperature was maintained below -5°C. The reaction resulted in a yellow slurry after 70 minutes of aging. H₂0 (8 L) was added to give a clear solution, which was agitated for 15 minutes. Then, the organic layer was separated. H₂0 (8 L) was charged to the organic layer. The mixture was agitated for 20 minutes, and then the organic layer was separated. Brine (10% solution, 4 L) was charged to the organic layer. The mixture was agitated for 20 minutes, and then the organic layer was separated. The organic phase was concentrated by vacuum distillation at approximately 30°C to 40°C and 28 inches Hg, resulting in a light brown residue (10.0 kg crude, approximately 9.5 kg product assumed, 58.0 mol, approximately 100% yield). A portion of the material was purified by distillation for characterization.

1H NMR (CDC1₃, 400 MHz): δ 4.18 (d, J = 6.8 Hz, 2H), 3.00 (s, 3H), 2.71 (m, 1H), 2.11 (m, 2H), 2.00-1.80 (m, 4H).

Step 2: Cyclobutylacetonitrile

A 100-L RB flask was set up with a mechanical stirrer, a thermocouple, an addition funnel, a N₂ inlet, and a condenser that is connected to a scrubber (11 L bleach and 5 L 2N NaOH). DMSO (30.3 L) (KF approximately 680 ppm) and NaCN (3030 g, 61.8 mol) were charged to the flask. The mixture was heated to approximately 75 °C by steam to dissolve most chunks of NaCN, resulting in a turbid solution. The product of Step 1 (9476 g, 57.7 mol) in DMSO (4 L) was added dropwise in 1 hour, 40 minutes while the temperature was maintained below approximately 87°C. The reaction was aged at approximately 85°C for 3 hours and cooled down to RT. H₂0 (24 L) and MTBE (24 L) were charged. The mixture was agitated, and the organic layer was separated. The aqueous layer was extracted with MTBE (18 L), and the combined organic layer was agitated with H₂0 (12 L) and separated. The organic layer was washed with 10% brine (4 L and 2 L), and concentrated by vacuum distillation at approximately 45°C and approximately 20 inches Hg, giving a light brown liquid (7.235 kg crude, 73.3% by GC assay, 5.30 kg product assay, 55.7 mol, 96.5% for two steps).

Ή NMR (CDCI₃, 400 MHz): δ 2.65 (m, 1H), 2.41 (d, J – 5.2 Hz , 2H), 2.18 (t, J = 6.8 Hz, 2H), 2.00-1.80 (m, 4H).

Example 2: Ethyl 4-cyclobutyl-3-oxobutanoate

THF (20 L) and zinc dust (2.75 kg, 42.0 mol) were charged under N₂ to a 50-L jacketed vessel with a thermocouple, an addition funnel and a condenser. The mixture was stirred, and chlorotrimethylsilane (0.571 kg, 5.26 mol) was added at RT. The mixture was heated at 67°C for 30 minutes. Cyclobutylacetonitrile (2.5 kg, 26.3 mol, product of Example 1) was added at 67°C. Ethyl bromoacetate (6.108 kg, 36.6 mol) was added to the mixture at approximately 67°C to 70°C for over 3 hours. After the addition, the mixture was heated at approximately 70°C for 1 hour and then cooled to approximately 0°C to 5°C. 10% H₂S0_{4 (aq.)} (35 L, 33.9 mol, approximately 1.3 eq.) was added slowly. The mixture was aged at RT for 1 hour. The organic layer was separated and subsequently washed with 10% aqueous citric acid (15 L, 7.88 mol, 0.3 eq.), 10% aqueous Na₂S₂0₅ (25 L), 10% Na₂S₂0_{5 (aq}.) (10 L), and 10% brine (10 L). The organic layer was concentrated in vacuo to afford the crude product (4.08 kg assay, 22.15 mol) in 84% yield. A part of the material was purified by distillation for characterization (with NMR in CDC1₃, approximately 10-15% enol-form of the compound was observed, major keto-form as shown.)

1H NMR (CDC1₃, 400 MHz): δ 4.19 (q, J = 7.1 Hz, 2 H), 3.38 (s, 2 H), 2.75-2.65 (m, 1H), 2.65-2.63 (m, 2 H), 2.19-2.08 (m, 2 H), 1.95-1.79 (m, 2 H), 1.73-1.60 (m, 2 H), 1.27 (t, J = 7.1 Hz, 3 H).

¹³C NMR (CDC1₃, 400 MHz): δ 202.2, 167.2, 61.3, 50.0, 49.3, 31.1, 28.4, 18.7,

14.1.

Example 3: Ethyl 2-chloro-4-c clobut l-3-oxobutanoate

Methyl t-butyl ether (30.2 L), and the crude product of Example 2 (3.78 kg assay,

20.52 mol) were charged to a 100-L RB flask with an overhead stirrer, an addition funnel, a thermometer, and an acid scrubber (with 2N NaOH at RT under N₂). Sulfuryl chloride (2.98 kg,

22.06 mol) was added at approximately 20°C to 23 °C over 1.5 hours. After addition, the mixture was cooled to approximately 5°C and then quenched with 1M K₃P0_{4 (aq.)} (23.6 L). The organic layer was separated and concentrated under vacuum to afford the crude chloride (4.487 kg, assume 100% yield, 20.52 mol), which was used in the next reaction without purification. A part of the material was purified by distillation for characterization (with NMR in CDC1₃,

approximately 10% enol-form of the compound was observed, major keto-form was shown below).

1H NMR (CDCI₃, 400 MHz): δ 4.73 (s, 1 H), 4.29 (q, J = 7.1 Hz, 2 H), 2.89-2.79 (m, 2 H), 2.79-2.69 (m, 1 H), 2.20-2.07 (m, 2 H), 1.98-1.78 (m, 2 H), 17.3-1.61 (m, 2 H), 1.32 (t, J = 7.1 Hz, 3 H).

¹³C NMR (CDC1₃, 400 MHz): δ 198.1, 165.0, 63.1, 60.9, 45.7, 31.0, 28.3, 18.7, 13.9. Example 4: -C clobut l-l-ethox -l,3-dioxobutan-2-yl 4-methoxybenzoate

The crude chloride product of Example 3 (4.487 kg assumed, 20.52 mol) and Ν,Ν-dimethylformamide (11.2 L) were charged to a 50-L jacketed vessel with a thermocouple and a condenser at RT under N₂. -Methoxybenzoic acid (3.75 kg, 24.62 mol) and TEA (2.285 kg, 22.57 mol) were added to the mixture. The mixture was heated at 55°C for 14 hours. The mixture was cooled to approximately 10°C, diluted with methyl tert-butyl ether (24 L), quenched with ¾0 (24 L). The organic layer was separated and subsequently washed with IN NaHC0₃ (20 L), then H₂0 (18 L) with NaCl (0.90 kg) and NaHC0₃ (0.45 kg). The organic layer was separated and concentrated in vacuo to afford the product (6.07 kg, 18.15 mol) in 88% assay yield. A part of the material was purified by distillation for characterization.

1H NMR (CDCI₃, 400 MHz): δ 8.09 (dt, J = 2.1, 9.0 Hz, 2 H), 6.96 (dt, J = 2.1, 9.0 Hz, 2 H), 5.66 (s, 1 H), 4.31 (q, J = 7.1 Hz, 2 H), 3.88 (s, 3 H), 2.86 (dd, J = 5.7, 7.6 Hz, 2 H, 2.83-2.74 (m, 1 H), 2.23-2.12 (m, 2H), 1.98-1.80 (m, 2 H), 1.74-1.65 (m, 2 H), 1.32 (t, J = 7.1 Hz, 3 H).

Example 5: (2 -3-Amino-4-cyclobutyl-l-ethoxy-l-oxobut-2-en-2-yl 4-methoxybenzoate

The crude product of Example 4 (5.97 kg, 17.85 mol), 1-propanol (12 L), and EtOH (12 L) were charged to a 100-L RB flask with an overhead stirrer and a thermometer at RT under N₂. NH₄OAc (4.82 kg, 62.5 mol) was added to the mixture. The mixture was heated at 50°C for 1 hour. The mixture was concentrated in vacuo to remove H₂0 azeotropically with continuous addition of 1-propanol (total approximately 24 L). The mixture was solvent-switched to i^‘PrOAc (24 L) under vacuum. The mixture was quenched with 2M K₃P0_{4 (aq}.) (17.85 L). The organic layer was separated and washed with 15% brine (18 L) twice. The organic layer was concentrated in vacuo to afford crude enamine product (5.95 kg, assume 100% yield, 17.85 mol).

1H NMR (CDC1₃, 400 MHz): δ 8.12 (d, J= 8.0 Hz, 2H), 6.98 (d, J= 8.0 Hz, 2H),

6.02 (s, 2H), 4.15 (q, J= 8 Hz, 2H), 3.89 (s, 3H), 2.60-2.53 (m, 1H), 2.33 (s, 2H), 2.13-2.06 (m,

2H), 1.91-169 (m, 4H), 1.20 (t, J = 8 Hz, 3H).

¹³C NMR (CDC1₃, 400 MHz): δ 165.7, 167.6, 163.6, 153.9, 132.1, 122.2, 113.9,

113.7, 112.5, 59.6, 44.5, 37.8, 33.9, 28.5, 28.4, 18.5, 14.4.

Example 6A: 3-[(tert-Butoxycarbonyl)amino]-4-cyclobutyl-l-ethoxy-l-oxobut-2-yl 4- methoxybenzoate

The crude product of Example 5 (5.92 kg, 17.75 mol) and MeOH (23.7 L) were charged to a 100-L RB flask with an overhead stirrer, a thermocouple, and an addition funnel at RT under N₂. Di-tert-butyl dicarbonate (5.81 kg, 26.6 mol) and sodium cyanoborohydride

(1.171 kg, 18.64 mol) were charged to the mixture. A solution of glycolic acid (1.485 kg, 19.53 mol) in MeOH (3.55 L) was added to the mixture drop wise at a rate to maintain the temperature at approximately 15°C to 22°C. The mixture was aged at approximately 20°C for approximately 8-10 hours. EtOAc (3.49 L, 35.5 mol) and a solution of glycine (0.866 kg, 11.4 mol) in H₂0 (11 L) were added to the mixture at RT. Then, 2M K₃P0_{4 (aq )} solution (17.75 L) was added. The mixture was aged for 20 minutes. The mixture was extracted with methyl tert-butyl ether (28 L). The organic layer was separated and washed subsequently with 2M K₃P0_{4 (aq.)} solution (17.75 L), 10% brine (17.75 L, twice). The organic layer was concentrated under vacuum to afford the desired two diastereoisomers in almost 1 : 1 ratio (7.30 kg, 16.76 mol) in 94% assay yield.

1H NMR (CDCI₃, 400 MHz): δ 8.02 (d, J= 8.0 Hz, 2H), 6.94 (d, J= 8.0 Hz, 1H),

6.93 (d, J= 8.0 Hz, 1H), 5.30 (d, J= 4.0 Hz, 0.5H), 5.17 (d, J= 4.0 Hz, 0.5H), 4.80 (d, J= 8.0 Hz, 0.5H), 4.63 (d, J = 8.0 Hz, 0.5H), 4.27-4.18 (m, 3H), 3.86 (s, 3H), 2.50-2.30 (m, 1H), 2.15- 2.00 (m, 2H), 1.89-1.60 (m, 6H), 1.43 -1.42 (m, 9H), 1.27 (t, J= 8.0 Hz, 3H).

Example 6B: 3-[(tert-Butoxycarbonyl)amino]-4-cyclobutyl-l-ethoxy-l-oxobut-2-yl 4- methoxybenzoate (First alternate procedure)

The crude product of Example 5 (19.2 g, 58.0 mmol) and MeOH (100 mL) were charged to an autoclave with a thermocouple at RT. Di-tert-butyl dicarbonate (19.0 g, 87.0 mmol) and 5% Ir/CaC0₃ (10.0 g) were charged to the mixture. The mixture was heated to 40°C under sealed conditions, where H₂ was transferred until the internal pressure became

approximately 200 psig. The mixture was heated at 40°C at approximately 200 psig for 20 hours. The reaction mixture was cooled to RT and filtered to remove the solid to afford a clear solution. EtOAc (5.7 mL, 58 mmol) and a solution of glycine (2.8 g, 38 mmol) in H₂0 (37 mL) were added to the mixture at RT. Then, 2M K₃P0_{4 (aq )} solution (58 mL) was added. The mixture was aged for 20 minutes. The mixture was extracted with methyl tert-butyl ether (130 mL). The organic layer was separated and washed subsequently with 2M ₃P0_{4 (aq.)} solution (58 mL), 10% brine (58 mL, twice). The organic layer was concentrated under vacuum to afford the desired two diastereoisomers in almost 1 :1 ratio (23 g, 52 mmol) in a 90% assay yield.

1H NMR (CDC1₃, 400 MHz): δ 8.02 (d, J= 8.0 Hz, 2H), 6.94 (d, J= 8.0 Hz, 1H), 6.93 (d, J= 8.0 Hz, 1H), 5.30 (d, J= 4.0 Hz, 0.5H), 5.17 (d, J- 4.0 Hz, 0.5H), 4.80 (d, J= 8.0 Hz, 0.5H), 4.63 (d, J= 8.0 Hz, 0.5H), 4.27-4.18 (m, 3H), 3.86 (s, 3H), 2.50-2.30 (m, 1H), 2.15- 2.00 (m, 2H), 1.89-1.60 (m, 6H), 1.43 -1.42 (m, 9H), 1.27 (t, J= 8.0 Hz, 3H). Example 6C: 3-[(tert-Butoxycarbonyl)amino]-4-cyclobutyl-l-ethoxy-l-oxobut-2-yl 4- methoxybenzoate (Second alternate procedure)

NaBH₄ (0.23 g, 6 mmol) and THF (5 mL) were charged to a 100-ml RB flask. The mixture was cooled to -10°C. Methanesulfonic acid (0.78 mL, 12 mmol) was charged slowly into the mixture at less than -8°C and the mixture was agitated for 15 minutes. A 0.3M solution of the crude product of Example 5 (1 g, 3 mmol) in THF was charged slowly into the mixture at below -8°C. The mixture was agitated for 16 hours. H₂0 (1 ml) was charged slowly into the mixture at 0°C, and the mixture was warmed to RT. Di-tert-butyl dicarbonate (1.31 g, 6 mmol) and 2M aqueous NaOH (3.75 ml) were charged into the mixture. The mixture was agitated for 2 hours at RT. An assay of the reaction mixture gave the product (1.23 g, 94%). Example 7A: Ethyl 3-f(tert-buyoxycarbonyl)aminoJ-4-cyclobutyl-2-hydroxybutanoate

The crude product of Example 6A (6.0 kg, 13.78 mol) and MeOH (24 L) were charged into a 10-gallon autoclave at RT. The mixture was heated to 70°C under sealed conditions, where NH₄ was transferred until the internal pressure became approximately 80 psig. The mixture was heated at 70°C at approximately 80 psig for 22 hours. The mixture was cooled to RT. NH₄ was vented at RT. DMSO (5.4 L) was added to the mixture, and the mixture was aged at RT for 1 hour. The mixture was transferred into a 100-L RB flask with an overhead stirrer and a thermometer. The autoclave was rinsed with MeOH, and the mixture and rinse liquid were combined. This combined mixture was concentrated to remove MeOH under vacuum. Then, the flask was rinsed with DMSO (2.6 L) to wash the walls. Total DMSO volume was 8.0 L. The mixture was heated to 70°C to dissolve the solid to afford a clear solution, which was cooled to RT slowly to afford a slurry. ¾0 (32.0 L) was charged for approximately 1.5 hours at 20°C to 27°C. After addition of H₂0, the mixture was aged at RT overnight and then cooled to 0°C to 5°C for 4 more hours. The mixture was filtered to collect the solid, which was washed with cold H₂0 (12 L). The solid was dried at 40°C in a vacuum oven with N₂ sweep (approximately 150 torr) to afford the crude product 5.63 kg (3.75 kg).

1H NMR (DMSO-d₆, 400 MHz): δ 7.20-7.15 (m, 2H), 7.25 (d, J= 12.0 Hz, 0.5H), 5.92 (d, J= 12.0 Hz, 0.44H), 5.52-5.44 (m, 1H), 3.83-3.81 (m, 0.5H), 3.74-3.62 (m, 1.5H), 2.29- 2.22 (m, 1H), 2.03-1.92 (m, 2H), 1.83-1.70 (m, 2H), 1.62-1.24 (m, 13H).

¹³C NMR (DMSO-d₆, 400 MHz) δ 175.2, 174.6, 155.5, 155.4, 78.0, 77.9, 74.4, 72.7, 51.9, 51.8, 38.8, 35.8, 33.3, 33.2, 33.0, 28.8, 28.7, 28.6, 28.5, 28.4, 28.2, 18.6, 18.5.

Example 7B: Ethyl 3-[(tert-buyoxycarbonyl)amino]-4-cyclobutyl-2-hydroxybutanoate

The crude product of Example 6A (6.0 g, 84 wt%, 11.57 mmol) and CaCl₂ (1.413 g, 12.73 mmol) and 7N NH₃ in MeOH (60 mL, 420 mmol) were charged into a 40 mL vial. The mixture was aged at approximately 33°C for 3 hours. The mixture was concentrated under reduced pressure to afford the product (7.8 g crude, assume 100% yield) as a tan solid. Example 8: Ethyl 3-amino-4-cyclobutyl-2-hydroxybutanoate hydrochloride

IP A (13.8 L) was charged into a 100-L RB flask with a mechanical stirrer, dry and clean with a thermometer and an addition funnel, followed by addition of the product of Example 7 (3.46 kg assay, 12.70 mol). HCI in IPA (5-6 M 13.8 L, 69 mol) was slowly added into the reaction mixture. The reaction mixture was heated at 50°C for 4 hours. The mixture was cooled to RT. Then, MTBE (28 L) was added to the mixture over 30 minutes. The reaction mixture was cooled to 0°C to 5°C by MeOH/ice bath for 1.5 hour. The mixture was filtered to collect the solid, which was washed with MTBE (7 L) twice. The wet cake was dried under vacuum with N₂ and sweep overnight to afford the product as an off-white solid (2.15 kg, 10.30 mol) in 76.6% overall yield for Examples 5-8.

1H NMR (DMSO-d₆, 400 MHz): δ 8.20-7.95 (m, 3H), 7.54-7.44 (m, 2H), 6.46 (d, J= 4.0 Hz, 0.5H), 6.26 (d, J= 8.0 Hz, 0.5H), 4.22 (s, 0.5H), 3.98 (s, 0.5H), 3.26 (s, 0.5H), 3.10 (d, J= 4.0 Hz, 0.5H), 2.45-2.36 (m, 1H), 2.00-1.96 (m, 2H), 1.81-1.39 (m, 6H).

1³C NMR (DMSO-d₆, 400 MHz) δ 174.1, 173.6, 71.2, 69.8, 51.7, 51.5, 36.0, 34.6,

31.7, 31.5, 28.0, 27.8, 27.7, 18.3, 18.1.

Exam le 9: Ethyl 3-amino-4-cyclobutyl-2-hydroxybutanoate hydrochloride (Recrystallization)

H₂0 (3.0 L), CH₃CN (6 L) and the product of Example 8 (2.00 kg, 9.58 mol) were charged to a 100-L RB flask with an overhead stirrer, a thermocouple and a condenser at RT under N₂. The mixture was heated to 65°C to get a clear solution. The mixture was cooled to 50°C to get a thin slurry. CH₃CN (6.0 L) was added at 50°C for over 1 hour. The mixture was cooled to 40°C. CH₃CN (9.0 L) was added at 40°C for over 1 hour. The mixture was cooled to 30°C. CH₃CN (18 L) was added at 30°C. The mixture was cooled to approximately 0°C to 5°C and stirred for 1 hour before filtration. The mixture was filtered, washed with CH₃CN (4 L) twice, and dried with N₂ stream to afford the recrystallized product as a white solid (1.887 kg, 9.04 mol, 94% isolated yield).

Ή NMR (DMSO-d₆, 400 MHz): δ 8.20-7.95 (m, 3H), 7.54-7.44 (m, 2H), 6.46 (d, J= 4.0 Hz, 0.5H), 6.26 (d, J= 8.0 Hz, 0.5H), 4.22 (s, 0.5H), 3.98 (s, 0.5H), 3.26 (s, 0.5H), 3.10 (d, J= 4.0 Hz, 0.5H), 2.45-2.36 (m, 1H), 2.00-1.96 (m, 2H), 1.81-1.39 (m, 6H).

¹³C NMR (DMSO-d₆, 400 MHz): δ 174.1, 173.6, 71.2, 69.8, 51.7, 51.5, 36.0, 34.6, 31.7, 31.5, 28.0, 27.8, 27.7, 18.3, 18.1.

Example 10: (lR,2S,5S)-N-(4-amino-l-cyclobutyl-3-hydroxy-4-oxobutan-2-yl)-3-[N-(t rt- butylcarbamoyl)-3-methyl-I^valyl]-6,6-dimethyl-3-azabicyclo[3A ]h

Hydroxybenzotiazole (HOBT, 4.83 g, 31.5 mmol), water (4.5 mL), (1R,2S,5S)-N- (4-amino- 1 -cyclobutyl-3 -hydroxy-4-oxobutan-2-yl)-3- [N-(tertbutylcarbamoyl)-3 -methylvalyl] – 6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2-carboxamide (30 g, 60.6 mmol), HCl salt product of Example 9 (13.79 g, 66.1 mmol), ethyl acetate (120 mL) and N-methyl-2-pyrrolidone (NMP, 30 mL) were added at 19°C to a three-necked 500mL RB flask equipped with an overhead stirrer and a thermocouple. N-methylmorpholine (13.3 mL, 121 mmol) was added to the mixture at 19°C. l-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDCI, 15.0 g, 78.0 mmol) was added to the mixture at 21°C. Ethyl acetate (30 mL) was then added to the mixture at 18°C.

The mixture was agitated at approximately 20°C to 24°C for about 16 hours. After the reaction was complete, ethyl acetate (120 mL) was added at 23°C. The mixture was washed with 10% aqueous potassium carbonate solution (180 mL) twice at approximately 20°C to 24°C. Then, the organic layer was washed with 3.3% aqueous HCl (180 mL) twice at approximately 12°C to 18°C. The organic layer then was washed with 10% aqueous potassium carbonate solution (180 mL) and water (180 mL). The organic layer was concentrated to approximately 100 mL volume and was added to heptane (900 mL) dropwise at approximately -10°C to -5°C to precipitate the product. The mixture was filtered and washed with heptane. The solid was dried in vacuo at approximately 50°C to 60°C overnight. 31.3 g of the product compound was obtained as a white solid in 99% yield. The above procedure is in accordance with the processes disclosed in U.S. Patent Application Publication No. US2010/519485 Al, the disclosures of which are herein

incorporated by reference. It will be appreciated that the processes disclosed therein can be modified without undue experimentation to prepare specifically desired materials. The results of H NMR and C NMR for the above procedure were consistent with those reported in U.S. Patent Application Publication No. US2010/519485 Al .

Example 11: (lR,5S)-N-[3-Amino-l-(cyclobutylmethyl)-2,3-dioxopropyl]-3-[2(S)-[[[(l,l- dimethylethyl)amino]carbonyl]amino]-3,3-dimethyl-l-oxobutyl]-6,6-dimazabicyclo[3.1.0]hexan-2(S)-carboxamide

Acetic acid (27.0 mL, 472 mmol) and MTBE (240 mL) at RT were added to a three-necked 1L RB flask equipped with an overhead stirrer, a thermocouple and a chiller. The mixture was cooled to approximately 14°C, then the product from Example 10 (30.0 g, 57.5 mmol) was charged at approximately 14°C. The mixture was cooled to approximately 11°C. 2,2,6,6-Tetramethylpiperidin-l-yl)oxyl (TEMPO, 9.97 g, 63.8 mmol) was added to the mixture. A pre-mixed solution containing 40% aqueous sodium permanganate (17.02 g, 48.0 mmol) and water (99 mL) at approximately 12°C to 14°C was added to the reaction mixture over about 2 hours. The mixture was agitated at approximately 12°C until completion.

After the reaction was complete, the mixture was cooled to approximately 1°C. Water (30 mL) was added, then aqueous layer was separated. The organic layer was then washed with water (150 mL) at approximately 0°C to 10°C, and then washed with a pre-mixed solution of sodium ascorbate (30.0 g, 151 mmol) in water (150 mL) and concentrated HCl (12.42 mL, 151 mmol) at approximately 5°C to 15°C. The mixture was agitated at approximately 5°C to 10°C for 2 hours; then aqueous layer was separated. The organic layer was further washed with 2.5 N HCl (120 mL) at approximately 0°C to 10°C and with water (150 mL) at

approximately 0°C to 10°C four times. The organic layer (approximately 170 mL) was then added dropwise to heptane (720 mL) at approximately -20°C to -15°C to precipitate the product. The mixture was then warmed to -5°C and filtered to collect the solid. The solid was washed with heptane, dried in a vacuum oven with nitrogen sweep at room temperature to afford 27.1 g of desired product of Formula II as a white solid in 91% yield.

The above procedure is in accordance with the processes disclosed in U.S.

Provisional Patent Application No.61/482,592 (unpublished), the disclosures of which are herein incorporated by reference. It will be appreciated that the processes disclosed therein can be modified without undue experimentation to prepare specifically desired materials. The results of 1H NMR and ¹³C NMR for the above procedure were consistent with those reported in U.S. Provisional Patent Application No.61/482,592 (unpublished).

……………………………………………………………….

13C NMR PREDICT

References

• 1 Kiser JJ, Burton JR, Anderson PL, Everson GT (May 2012). “Review and Management of Drug Interactions with Boceprevir and Telaprevir”. Hepatology 55 (5): 1620–8. doi:10.1002/hep.25653. PMC 3345276. PMID 22331658.
• 2
• Degertekin B, Lok AS (May 2008). “Update on viral hepatitis: 2007″. Curr. Opin. Gastroenterol. 24 (3): 306–11. doi:10.1097/MOG.0b013e3282f70285. PMID 18408458.
• 3
• Njoroge FG, Chen KX, Shih NY, Piwinski JJ (January 2008). “Challenges in modern drug discovery: a case study of boceprevir, an HCV protease inhibitor for the treatment of hepatitis C virus infection”. Acc. Chem. Res. 41 (1): 50–9. doi:10.1021/ar700109k. PMID 18193821.
• 4
• “Boceprevir – FDA Antiviral Drugs”. FDA. FDA. April 2011. Retrieved April 2014.
• 5
• “Interim Results from Boceprevir Phase II Study in Genotype 1 Treatment-Naive Hepatitis C Patients Presented At EASL – Forbes.com” (Press release). Forbes.com. Retrieved 2008-05-19.
• 6
• “FDA Approves Merck’s VICTRELIS™ (boceprevir), First-in-Class Oral Hepatitis C Virus (HCV) Protease Inhibitor” (Press release). Merck & Co. Retrieved 2011-05-14.
• 7
• http://www.hcvadvocate.org/news/reports/EASL_2009/Advocate_EASL_2009_Coverage.htm
• 8
• Poordad, F et al. (March 2011). “Boceprevir for Untreated Chronic HCV Genotype 1 Infection”. N Engl J Med. 364 (13): 1195–206. doi:10.1056/NEJMoa1010494. PMID 21449783.
• 9
• Jensen, D (March 2011). “A New Era of Hepatitis C Therapy Begins”. N Engl J Med. 364 (13): 1272–1273. doi:10.1056/NEJMe1100829. PMID 21449791.
• 10

Bacon, B et al. (March 2011). “Boceprevir for Previously Treated Chronic HCV Genotype 1 Infection”. N Engl J Med. 364 (13): 1207–17. doi:10.1056/NEJMoa1009482. PMC 3153125. PMID 21449784.

Systematic (IUPAC) name
(1R,5S)-N-[3-Amino-1-(cyclobutylmethyl)-2,3-dioxopropyl]-3-[2(S)-[[[(1,1-dimethylethyl)amino]carbonyl]amino]-3,3-dimethyl-1-oxobutyl]-6,6-dimethyl-3-azabicyclo[3.1.0]hexane-2(S)-carboxamide
Clinical data
Trade names	Victrelis
AHFS/Drugs.com	Consumer Drug Information
MedlinePlus	a611039
Licence data	US FDA:link
Pregnancy category	US: X (Contraindicated)
Legal status	US: ℞-only
Routes of administration	Oral
Pharmacokinetic data
Protein binding	75% [1]
Half-life	3.4 hours [1]
Identifiers
CAS Registry Number	394730-60-0
ATC code	J05AE12
PubChem	CID 10324367
ChemSpider	8499830
UNII	89BT58KELH
ChEMBL	CHEMBL218394
NIAID ChemDB	398493
Chemical data
Formula	C27H45N5O5

Magnolia virginiana

Honokiol, from magnolia bark, shuts down cancer cells in lab

Compound in magnolia may combat head and neck cancers

Honokiol, from magnolia bark, shuts down cancer cells in lab

Magnolias are prized for their large, colorful, fragrant flowers. Does the attractive, showy tree also harbor a potent cancer fighter?

Yes, according to a growing number of studies, including one from VA and the University of Alabama at Birmingham that is now online in the journal Oncotarget.

The study focused on squamous cell head and neck cancers, a scourge among those who use tobacco and alcohol. According to the National Cancer Institute, at least 3 in 4 head and neck cancers are caused by the use of tobacco and alcohol. The cancers have only a 50 percent survival rate, killing some 20,000 Americans each year.

Enter honokiol–chemical formula C18H18O2. As one of the major active compounds in magnolia extract, the phytochemical has been used for centuries in traditional Chinese and Japanese medicine to treat anxiety and other conditions. More recently, scientists have been discovering that the compound, found in magnolia bark, is a wily and versatile adversary of cancer. It seems to exploit many biochemical pathways to shrink tumors of various types, or to keep them from growing in the first place.

The Alabama scientists have now shown how it works against head and neck cancers: It blocks a protein called epidermal growth factor receptor, or EGFR. Prior research has found that almost all head and neck cancer cells display an over-abundance of the protein, and it had been suggested in the literature as a potential target.

The VA-UAB team says, based on its lab studies, that honokiol binds more strongly with EGFR than does the drug gefitinib (sold as Iressa), which is commonly used to treat head and neck cancers.

The researchers tested honokiol on cell lines derived from human cancers of the oral cavity, larynx, tongue, and pharynx. In all cases, the botanical shut down the aberrant cells. The team also tested it against tumors implanted into mice, with similar results.

Senior author Dr. Santosh K. Katiyar and his colleagues wrote, “Conclusively, honokiol appears to be an attractive bioactive small molecule phytochemical for the management of head and neck cancer which can be used either alone or in combination with other available therapeutic drugs.”

Katiyar has published extensively in the past on other natural substances that work against tumors, especially skin cancer. Some of his recent work has focused on compounds in green tea, for example, and grape seed proanthocyanidins.

Purification

There are several methods for purifying and isolating honokiol. In nature, honokiol exists with its structural isomer magnolol, which differs from honokiol only by the position of onehydroxyl group. Because of the very similar properties of magnolol and honokiol, purification has often been limited to a HPLC or electromigration. However, methods developed in 2006 by workers in the lab of Jack L. Arbiser, took advantage of the proximity of the phenolic hydroxyl groups in magnolol, which form a protectable diol, to generate amagnolol acetonide (Figure 1), with a subsequent simple purification via flash chromatography over silica.^[4]

Figure 1

Magnolol and Honokiol are normally inseparable. Honokiol is easily separable from the protected magnolol acetonide

Additionally a rapid separation approach was published in the Journal of Chromatography A in 2007. The process uses high-capacity high-speed countercurrent chromatography(high-capacity HSCCC).^[5] Through this method honokiol can be separated and purified to above 98% purity with a high yield in under an hour.

Honokiol is a lignan isolated from the bark, seed cones, and leaves of trees belonging to the genus Magnolia. It has been identified as one the chemical compounds in some traditional eastern herbal medicines along with magnolol, 4-O-methylhonokiol, andobovatol.

Traditional medicine

Seed Cone

Extracts from the bark or seed cones of the Magnolia tree have been widely used in traditional medicine in China, Korea, and Japan.^[2]

Houpu has traditionally been used in Eastern medicine as analgesic and to treat anxiety and mood disorders.^[2][6] However, it has been shown to treat a number of other conditions. In China, magnolia bark is called Houpu and is most commonly taken from the Magnolia obovata and the Magnolia officinalis species.^[7] Some Chinese traditional formulas containing Houpu include Banxia Houpu Tang (半夏厚朴丸), Xiao Zhengai Tang, Ping Wei San(平胃散) and Shenmi Tang.^[2] Japanese Kampo formulas include, Hange-koboku-to (半夏厚朴湯) and Sai-boku-to (柴朴湯).^[2][6]

Seeds

Modern medicine

In the late 1990s, honokiol saw a revival in interest as a potent and highly tolerable antitumorigenic and neurotrophiccompound.

Alternative medicine

Currently there are a large number of supplements containing honokiol on the market, and its use has been widely well received among practitioners of new age, homeopathic, and holistic medicine

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Mature Magnolia fruit just starting to open, with a few seeds visible

Honokiol

Names
IUPAC name 2-(4-hydroxy-3-prop-2-enyl-phenyl)- 4-prop-2-enyl-phenol
Other names houpa, hnk
Identifiers
CAS Registry Number	35354-74-6
ChEMBL	ChEMBL16901
ChemSpider	65254
InChI[show]
Jmol-3D images	Image
KEGG	C10630
PubChem	72303
SMILES[show]
Properties
Chemical formula	C18H18O2
Molar mass	266.334 g/mol
Appearance	White solid
Solubility in water	sparingly (25 °C)
Related compounds
Related biphenols	diethylstilbestrol, dihydroxyeugenol
Related compounds	magnolol. 4-O-Methylhonokiol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Magnolia seeds and fruit on a tree in northern Argentina

Magnolia grandiflora

http://www.google.com/patents/WO2006107451A2?cl=en

The root and stem bark of Magnolia has been used as a traditional Chinese medicine for the treatment of thrombotic stroke, gastrointestinal complaints, and anxiety. Honokiol (HNK), a substituted biphenyl and an active component isolated and purified from Magnolia, has anti-oxidant, antithrombosis, antibacterial, neurotrophic, xanthine oxidase inhibitory, and anxiolytic effects (Taira et al., Free Radic Res Commun. 1993;19 Suppl l:S71-77; Teng et al. Thromb Res. 1988;50:757-765; Clark et al., J. Pharm. Sci. 1981;70:951-952; Chang et al., Anticancer Res. 1994;14:501-506; Kuribara et al., J. Pharm Pharmacol. 1998;50:819-826; Esumi et al., Bioorg & Medicinal Chem Let 2004, 14: 2621-25).

In the early 1990s, reports of HNK’s anticancer effects were published. In 1994, Hirano et al (Life Sci. 1994;55(13): 1061-9) examined the anti leukemic-cell efficacy of 28 naturally occurring and synthetic flavonoids and 11 naturally occurring ligands on human promyelocytic leukemic cell line HL-60, and cytotoxicity of these compounds was compared with four clinical anti-cancer agents. HNK was identified as one of the most potent compounds in this screen, with an IC₅₀ value less than 100 ng/ml. In 1998, Hibasami et al. demonstrated that HNK induced apoptosis in human lymphoid leukemia Molt 4B cells (Hibasami et al., Int. J. MoI. Med. 1998).

HNK has also been found to induce apoptosis in human squamous cell lung cancer CH27 cells (Yang SE, et al Biochem Pharmacol. 2002;63:1641-1651) and in human colorectal RKO cells (Wang et al World J Gastroenterol. 2004; 10:2205-2208). In 2004, Chen et al. (World J Gastroenterol. 2004; 10: 3459-3463) reported that HNK was effective in an in vivo animal model of human colon cancer by inhibiting tumor growth and prolonging the lifespan of tumor bearing mice.

Honokiol is an inhibitor of angiogenesis and antitumor activity in vivo. HNK can cause apoptosis in tumor cells and inhibit angiogenesis through blocking phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2), the major mitogenic and chemoattractant endothelial growth factor (Bai et al. (2003) J. Biol. Chem. 278, 35501- 35507). Honokiol also exhibits direct antitumor activity through induction of apoptosis through tumor necrosis factor apoptosis-inducing ligand (TRAIL/ Apo2L) signaling and has been found to be highly effective against angiosarcoma in nude mice in vivo (Bai et al. (2003) J. Biol. Chem. 278, 35501-35507).

Esumi et al. (Biorganic & Medicinal Chemistry Letters (2004) 14: 2621-2625) describe a synthesis method to produce HNK. This report also evaluates the structure activity relationship of O-methylated and/or its hydrogenated analogs of HNK in an in vitro neurotrophic assay. Esumi et al. conclude that the 5-allyl and 4′-hydroxyl groups are essential for the neurotrophic activity of HNK.

PCT Publication No. WO 02/076393 and U.S. Publication No. 2004/0105906 to Emory University describe pharmaceutical compositions and methods of treating conditions such angiogenic-, neoplastic-, and cancer-related conditions and skin conditions by administration of honokiol-type and/or magnolol-type compounds, as shown in Figures 1-4. For example, such compositions comprise at least one compound of formula Al :

AI wherein R₁, R₂, R₃, R₄, R₅, R₁, R₂, R₃, R₄, and R’₅ can be independently selected from groups that include, but are not limited to, hydrogen, hydroxyl groups, amides, amines, hydrocarbons, halogenated hydrocarbons, cyclic hydrocarbons, cyclic heterocarbons, halogenated cyclic heterocarbons, benzyl, halogenated benzyl, organo selenium compounds, sulfides, carbonyl, thiol, ether, dinitrogen ring compounds, thiophenes, pyridines, pyrroles, imidazoles, and pyrimidines. Honokiol-type and magnolol-type compounds are shown to inhibit SVR cell proliferation.

In November of 2004, Arbiser et al. reported that honokiol inhibited the growth of multuple myeloma cell lines via induction of Gl growth arrest, followed by apoptosis with IC50 values at 48h of 5 to 10 μg/mL. It was also reported that honokiol inhibited growth of doxorubin (Dox)-resistant (RPMI-Dox40), mephalan resistant (RPMI-LR5) and dexamethasone (Dex)-resistant (MM. IR) cell lines. It was suggested that the mechanism of honokiol triggered cytotoxicity is the honokiol induced increased expressin of Bax and Bad, down-regulated Mc-I protein expression, followed by caspase-8/9/3 cleavage, (Arbiser, J. et al. Poster at the American Society of Hematology Annual Meeting, 2004. Abstract published online November 4, 2004).

In July of 2005, Battle et al. reported that honokiol induces caspase-dependent apoptosis in B-cell chronic lymphocytic leukemia (B-CLL) cells (Blood. July 2005; 106:690- 697). Honokiol induced caspase-dependent cell death in all of the B-CLL cells examined, which were primary tumor cells derived from B-CLL patients, and was more toxic toward B- CLL cells than to normal mononuclear cells. The honokiol-induced apoptosis was characterized by the activation of caspase-3, -8, and -9 and cleavage of poly(adenosine diphosphate-ribose) polymerase (PARP). It was also reported that honokiol enhanced cytotoxicity induced by fludarabine, cladribine, or chlorambucil.

In September 2005, Ishitsuka et al reported that honokiol overcomes conventional drug resistance in human multiple myeloma by induction of caspase-dependent and – independent apoptosis (Blood, 1 September 2005, Vol. 106, No. 5, pp.1794-1800). HNK induced cytotoxicity in human multiple myeloma (MM) cell lines and tumor cells from patients with relapsed refractory MM through induction of apoptosis via both caspase- dependent and -independent pathways. HNK also enhanced MM cell cytotoxicity and apoptosis induced by bortezomib.

It is an object of the present invention to provide new compounds, compositions, methods and uses for the treatment of disorders associated with angiogenesis, cell proliferation, tumor growth, tumorogenesis, and myeloma.

the intermediates for the synthesis of honokiol are 3-allyl-4- hydroxybenzeneboronate 5 and 4-allyl-2-bromophenol 9. The boronate 5 can be prepared from 2-iodophenol 1 by bromination, followed by Suzuki coupling to introduce the allyl group, and boronation under Suzuki conditions. Compound 9 can be prepared from 4- iodophenol 6 by bromination and allylation (Suzuki coupling). The coupling of 5 and 9 under Suzuki conditions can yield honokiol from Suzuki coupling, not other allyl-oriented products from the Heck reaction, as it was shown that Suzuki coupling can succeed in the presence of C=C double bond (see Miyaura, N.; Suzuki, A. (1995), Chem. Rev. 95, 2457- 2483; and Suzuki, A. (1999), J. Organometal. Chem. 576, 147-168, and the references cited therein). Thus, honokiol and derivatives can be synthesized from commercially available starting materials in 6 steps (Scheme 1). Scheme 1

Treatment of honokiol with TMS-diazomethane in methanol results in mono- and di- methylated compounds I-III, and hydrogenation of honokiol with Wilkinson’s catalyst yields di- and tetrahydrohonokiols VI-VIII, as reported by Esumi, T. et al. (2004), Bioorg. Med. Chern. Lett. 14, 2621-2625. The amino and fluoro analogues (IV and V) can be constructed from iodoacetanilide under Suzuki coupling conditions. From 2-iodoacetanilide 10, after bromination, allylation, and boronation, the boronated intermediate 13 can be prepared. The other bromo intermediate 16 can be prepared from 4-iodoacetanilide 14 via bromination and allylation. The coupling of boronate 13 and bromide 16 under Suzuki conditions can afford, after deprotection, the compound IV. Diazotization followed by Schiemann reaction can convert the amino analogue TV to fluoro analogue V (Scheme 2).

The dimethoxy honokiol derivative, III, can also be prepared, for example, by the treatment of honokiol with potassium carbonate, iodomethane. (Scheme 2a). The hydrogenated honokiol analog can alternatively be prepared by the hydrogenation of honokiol with sodium borohydride and nickel(II) chloride to yields tetrahydrohonokiols VI- Vπi. (Scheme 2a). Scheme 2a

The preparation of the vinyl analogue IX is based on combining the Wittig reaction with Suzuki coupling. The intermediate aldehyde 18 can be prepared from 4-iodophenol 17 via the Reimer-Tiemann reaction, while 3-bromo-4-hydroxybenzenealdehyde 23 can be prepared from para-hydroxybenzoic ester 21 via bromination and reduction. The Wittig reaction of these two aldehydes can yield the corresponding vinyl substituted benzenes 19 and 24. Compound 19 can afford the boronate 20, which can be coupled with 24, to yield the compound IX (Scheme 3).

Reagents and conditions: (a) CHCl₃, aq. NaOH, 70 °C; (b) Ph₃PCH₃Br₁ n-BuLi, THF; (c) PdC!₂(dppf), dppf, KOAc, dioxane, bis(pinacoato)diboron, 80 °C; (d) DIBALH, -70 °C; (e) PdCI₂(dppf), dppf, K₃PO₄, dioxane, reflux.

For the synthesis of honokiol analogues with changed positions of the allyl or hydroxyl groups, the boronate 5, and the bromophenols 4 and 9 can be used as intermediates. Suzuki coupling of one of these intermediates with an appropriate halide or boronate can provide the compounds X-XVII. Compounds X-XII and XTV-XV can be prepared by Suzuki coupling of boronate 5 with an appropriate halide. Halide 25, needed for compound X, can be prepared from 2-bromo-6-iodophenol 2 via allylation, while the intermediate, 5-allyl-2- bromophenol 29 for compound XI, can be furnished from 3-iodophenol 26 via bromination and allylation. The preparation of halide 5-allyl-3-bromophenol 33, an intermediate for the synthesis of compound XIV, requires an organothallium reagent. The thallation of 3- bromophenol 30 followed by treatment with iodide can yield 3-bromo-5-iodophenol 32. After allylation, the allyl-substituted intermediate 33 can be prepared. The synthesis of compound XII can begin with 2-iodoacetanilide 10, via sulfonation, nitration, and reduction to obtain the intermediate 36. Aniline 36, after diazotization, followed by acid and base treatments, will afford 2-amino-3-iodophenol 37. Diazotization, Sandmeyer reaction, and allylation of compound 37 will yield halide 39. By a coupling reaction of these halides (25, 29, 33, and 39) with boronate 5, these compounds (X-XII, and XTV) can be prepared. Compound XV can be synthesized by Suzuki coupling of halide 4 with boronate 5 (Scheme 4).

Scheme 4

Alternatively, compounds X, XV, and XVII can be synthesized by an allylation- Claisen pathway. Biphenol compounds can be reacted first with potassium carbonate and allyl bromide, followed by reaction with BCl₃ to yield honokiol-like compounds, for example, X, XV, and XVII. (Scheme 4a). To a cooled solution (O⁰C with an ice bath) of diallyl starting material (1 eq.) in dry diehloromethane (Concentration of the solution : 0.1 mol.L^“1) was added dropwise a solution Of BCl₃ (IM in diehloromethane; 1.5 eq. = 0.75 eq for each allyl group). The reaction is then stirred at O⁰C until disappearance of the starting material on TLC (If after 15 minutes, the reaction is not complete, 1 more equivalent of BCl₃ can be added). After hydrolysis with water (about same volume than diehloromethane), the two layers are separated. The organic layer is washed again with water, dried under MgSO₄ then evaporated under vacuum. The residue is finally purified by column chromatography to give the di- hydroxy derivative . Scheme 4a

Bromide 9 is also a useful intermediate for coupling with some boronates. For example, Suzuki coupling of bromide 9 with boronate 42, which is prepared from 4-bromo-3- iodophenol 40 via allylation and boronation, can yield the compound XIII. Similarly, the coupling between bromide 9 and boronate 43 can afford the compound XVT. The compound XVII can be prepared from 4-allyl-2-bromophenol 9 via boronation followed by Suzuki coupling with 2-allyl-6-bromophenol 25 (Scheme 5).

The compounds XVIII and XIX can be synthesized from commercially available bisphenol 45 and the dihydroxynaphthalene-disulfuric acid salt 47. Thus, the bisphenol 45, through the Williamson reaction and Claisen rearrangement, can be converted to compound XVπi. Similarly, desulfonation of dihydroxynaphthalene-disulfuric acid salt .47, followed by the Williamson reaction and Claisen rearrangement, can produce the compound XIX (Scheme 6).Scheme 6

Dioxolane compounds can be prepared from magnoliol by reaction of magnoliol with 2,2′-dimethoxypropane and p-toluenesulfonic acid. (Scheme 7). This synthesis also provides a method of separating mixtures of honokiol and magnoliol. Scheme 7

The following examples are offered by way of illustration and not by way of limitation.

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http://www.google.com/patents/US20080300298

VILAZODONE

Vilazodone hydrochloride; 163521-08-2; Vilazodone HCl; Viibryd; UNII-U8HTX2GK8J; EMD-68843

NO SYNTHESIS IS THIS POST, ONLY SPECTRAL DATA DISCUSSED

SEE MORE SPECTROSCOPY DATA AT………..http://orgspectroscopyint.blogspot.in/2015/06/vilazodone.html

ENJOY THE INTERPRETATIONS

Vilazodone (United States trade name Viibryd veye-brid) is a serotonergic antidepressant developed by Clinical Data for the treatment of major depressive disorder. The chemical compound was originally developed by Merck KGaA (Germany).^[2] Vilazodone was approved by the FDA for use in the United States to treat major depressive disorder in 2011.^[3][4][5]

Medical uses

According to two eight-week, randomized, double-blind, placebo-controlled trials in adults, vilazodone elicits an antidepressant response after one week of treatment. After eight weeks, subjects assigned to vilazodone 40 mg daily dose (titrated over 2 weeks) experienced a significantly higher response rate than the group given placebo (44% vs 30%, P = .002). Remission rates for vilazodone were not significantly different versus placebo.^[6]

According to an article on the United States approval of vilazodone written by FDA staff, “it is unknown whether [vilazodone] has any advantages compared to other drugs in the antidepressant class.”^[7]

PAPER FROM OPRD

Scale-Up Synthesis of Antidepressant Drug Vilazodone

A scale-up synthesis of antidepressant drug vilazodone was accomplished in five steps. Friedel–Crafts acylation of 1-tosyl-1H-indole-5-carbonitrile with 4-chlorobutyryl chloride, selective deoxygenation in NaBH₄/CF₃COOH system coupled with ethyl 5-(piperazin-1-yl)-benzofuran-2-carboxylate hydrochloride, one-step deprotection and esterolysis, and the final ammonolysis led to the target molecule vilazodone in 52.4% overall yield and 99.7% purity. This convenient and economical procedure is remarkably applicable for scale-up production.

5-(4-(3-(5-Cyano-1H-indol-3-yl)butyl)piperazin-1-yl)benzofuran-2-carboxamide (1)

 

SEE MORE SPECTROSCOPY DATA AT………..http://orgspectroscopyint.blogspot.in/2015/06/vilazodone.html

VIIBRYD Tablets for oral administration contain polymorph Form IV vilazodone hydrochloride (HCl), a selective serotonin reuptake inhibitor and a 5HT_1A receptor partial agonist.

Vilazodone HCl is 2-benzofurancarboxamide, 5-[4-[4-(5cyano-1H-indol-3-yl)butyl]-1-piperazinyl]-, hydrochloride (1:1). Its molecular weight is 477.99. The structural formula is:

In addition to the active ingredient, VIIBRYD Tablets contain lactose monohydrate, microcrystalline cellulose, magnesium stearate, colloidal silicon dioxide, polyvinyl alcohol, titanium dioxide, polyethylene glycol, talc, FD&C Blue #1 (40 mg only), FD&C Yellow #6 (20 mg only) and FD&C Red #40 (10 mg only).

TENELIGLIPTIN

Teneligliptin (INN; trade name Tenelia) is a pharmaceutical drug for the treatment of type 2 diabetes mellitus. It is approved for use in Japan.^[1] It belongs to the class of anti-diabetic drugs known as dipeptidyl peptidase-4 inhibitors or “gliptins”.^[2] {(2S,4S)-4-[4-(3-Methyl-1-phenyl-1H-pyrazol-5-yl)-1-piperazinyl]-2-pyrrolidinyl}(1,3-thiazolidin-3-yl)methanone

Teneligliptin was launched in Japan in 2012 by Mitsubishi Pharma and Daiichi Sankyo for the treatment of type 2 diabetes mellitus. In 2013, the indication was partially changed to include it as a combination therapy with existing oral hypoglycemic agents, such as biganides, alpha-glucosidaseinhibitors, rapid-acting insulin secretagogues, and insulin preparations, as well as sulfonylureas and thiazolidines that had been approved for the combination.

In 2014, the product was registered in KR for the treatment of type 2 diabetes mellitus.
In 2013, Mitsubishi Tanabe Pharma filed for approval in Japan for use of the compound as combination therapy for the treatment of diabetes type 2.

3-{(2S,4S)-4-[4-(3-methyl-l -phenyl- 1 H- pyrazol-5-yl)- l-piperazinyl]-2-pyrrolidinylcarbonyl}-l , 3-thiazolidine is represented structurally by a compound of formula (I):

Teneligliptin (CAS 760937-92-6) is a novel, potent and long-lasting dipeptidyl peptidase-4 inhibitor in treatment of type 2 diabetes. Dipeptidyl-peptidase-4 (DPP- 4) inhibitor has been demonstrated to improve glycemic control, in particular postparandial hyperglycemic control.

Despite of their common mechanism of action, DPP-4 inhibitors show marked structural heterogeneity. DPP-4 inhibitors may be classified into peptidomimetic (i.e. sitagliptin, vildagliptin, saxagliptin, and anagliptin) and non-peptidomimetic (i.e. alogliptin and linagliptin) subtypes.

Teneligliptin, is chemically known as a 3- {((2S,4S)-4-(4-(3-methyl-1-phenyl-1H-pyrazol-5-yl)piperazin-1-yl)pyrrolidin-2-yl 25 carbonyl}thiazolidine hemipentahydrobromide hydrate and is peptidomimetic with the molecular formula of C22H30N6OS.2½HBr.xH2O and molecular weight of 642.88 g/mol for hemipentahydrobromide. The hydrate can be from mono to dihydrate.

U.S. Patent No. 7,074,794 B2 (the US ‘794) discloses teneligliptin as L-proline derivative and its pharmaceutically acceptable salts which exhibits a Dipeptidyl 5 peptidase IV (DPP-IV) inhibitory activity, which is useful for the treatment or prophylaxis of diabetes, obesity, HIV infection, cancer metastasis, dermopathy, prostatic hyperplasia, periodontitis, autoimmune diseases and the like.

The example-222 of the US ‘794 discloses the process for the preparation of teneligliptin as trihydrochloride salt U.S. Patent No. 8,003,790 B2 (the US ‘790) discloses salts of proline derivative, solvate thereof and production method thereof. In particular, the US ‘790 discloses 2.0 hydrochloride or 2.5 hydrochloride; 2.0 hydrobromide or 2.5 hydrobromide, and hydrates thereof teneligliptin.

The US ‘790 B2 further discloses different salts 15 of teneligliptin which are incorporated herein as reference in their entirety U.S. PG-Pub. No. 2011/0282058 A1 discloses salts of 3-{((2S,4S)-4-(4-(3-methyl- 1-phenyl-1H-pyrazol-5-yl)piperazin-1-yl)pyrrolidin-2-ylcarbonyl}thiazolidine with mono-, di- and tri-basic acids or a solvate thereof. 20 International (PCT) publication No. WO 2012/165547 A1 discloses a process for preparation of teneligliptin and pharmaceutically acceptable salts thereof.

International (PCT) publication No. WO 2007/127635 A2 (the WO ‘635 A2) discloses a process for the preparation of diketo-piperazine and piperidine 25 derivatives. In particular, the WO ‘635 A2 discloses the process for preparation of 4-oxo-2-(thiazolidine-3-carbonyl)-pyrrolidine-1-carboxylic acid tert-butyl ester [herein compound (III)] by reacting piperazine with aryl halide.

International (PCT) publication No. WO 2012/099915 A1 (the WO ‘915 A1) 5 discloses the process for the preparation of deuterated thiazolidine derivatives. The WO ‘915 A1 also discloses the process for the preparation of 1-(3-methyl-1- phenyl-1H-pyrazol-5-yl)piperazine herein compound (V) by condensation of 5- chloro-3-methyl-1-phenyl-1H-pyrazole with piperazine.

Bioorganic & Medicinal Chemistry, 20(19), 5705-5719 (2012) discloses the process for the preparation of 1-(3-methyl-1-phenyl-1H-pyrazol-5-yl)piperazine herein compound (V) by deprotection of Boc-protected 1-(3-methyl-1-phenyl-1Hpyrazol-5-yl)piperazine with triflouroacetic acid.

U.S. Patent Nos. 7,807,676 B2 and 7,807,671 B2 discloses a process for the preparation of 1-(3-methyl-1-phenyl-1H-pyrazol-5-yl)piperazine by condensation of 5-chloro-3-methyl-1-phenyl-1H-pyrazole with piperazine in presence of n-BuLi in tetrahydrofuran. Bioorganic & Medicinal Chemistry, 14(11), 3662-3671 (2006),

Bioorganic & Medicinal Chemistry, 20(16), 5033-5041 (2012) and U.S. Patent Nos. 7,807,676 B2 and 7,807,671 B2 discloses a process for the preparation of (2S,4R)-tert-butyl 4-hydroxy-2-(thiazolidine-3-carbonyl)pyrrolidine-1-carboxylate by reacting (2S,4R)-1-(tert-butoxycarbonyl)-4-hydroxypyrrolidine-2-carboxylic acid with 25 thiazolidine in presence of HOBT and EDC.HCl in dimethylformamide solvent.

Bioorganic & Medicinal Chemistry, 15(2), 641-655 (2007) discloses a process for the preparation of (2S,4R)-tert-butyl 4-hydroxy-2-(thiazolidine-3- carbonyl)pyrrolidine-1-carboxylate by treating (2S,4S)-tert-butyl 4-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-2-(3-thiazolidinylcarbonyl)pyrrolidine-1- carboxylate with tetrabutylammonium fluoride in tetrahydrofuran.

Bioorganic & Medicinal Chemistry, 20(19), 5705-5719 (2012) discloses the 5 process for the preparation of herein compound (II) after by reacting 1-(3-methyl- 1-phenyl-1H-pyrazol-5-yl)piperazine herein compound (V) with (2S,4R)-tert-butyl 4-hydroxy-2-(thiazolidine-3-carbonyl)pyrrolidine-1-carboxylate in presence of sodium triacetoxyborohydride. There is provided different alternative processes for the preparation of teneligliptin and intermediates thereof.

Bioorganic & Medicinal Chemistry, 20(19), 5705-5719 (2012) also discloses the process for the preparation of 4-[4-(5-methyl-2-phenyl-2H-pyrazol-3-yl)-piperazin- 1-yl]-2-(thiazolidine-3-carbonyl)pyrrolidine-1-carboxylic acid tert-butyl ester [herein compound (II)] after by reacting 1-(3-methyl-1-phenyl-1H-pyrazol-5- 15 yl)piperazine [herein compound (V)] with (2S,4S)-tert-butyl 4-[[(1,1- dimethylethyl)dimethylsilyl]oxy]-2-(3-thiazolidinylcarbonyl)pyrrolidine-1- carboxylate in presence of trifluoromethylsulfonic anhydride and diisopropylethylamine. 3 – [[(2S, 4S) -4- [4- (3- methyl-1-phenyl–1H- pyrazol-5-yl) -1-piperazinyl ] -2-pyrrolidinyl] carbamoyl] thiazolidine, having the formula below, is a very novel DPP-4 inhibitor potential.

World Patent Application No. W02012099915 for Ge Lieting discloses a process for the preparation route is as follows:

Journal B10rganic & Medicinal Chemistry, 2012, 20, 5705-5719 also discloses a preparation method for Ge Lieting, the route is as follows:

[0009] 1- (3-methyl-1-phenyl-5-pyrazolyl) piperazine, was prepared for the Ge Lieting key intermediate. Journals B10rganic & Medicinal Chemistry, 2012,20,5705-5719 reported the preparation of the intermediates prepared route is as follows:

[0011] The preparative route after the N-Boc-N- acetoacetyl piperazine phenylhydrazine and methanesulfonic acid in an ethanol solution of the reaction at room temperature 14h, concentrated under reduced pressure after addition of pyridine.Was added phosphorus oxychloride in pyridine, 20h post treatment reaction at room temperature the reaction system. The compound obtained above was then added trifluoroacetic acid was dissolved in methylene chloride after, after treatment at room temperature for 1.5h to give 1- (3-methyl-1-phenyl-5-pyrazolyl) piperazine.

The reaction process requires mesylate mesylate flammable, easy-absorbent deliquescence, and has a strong corrosive and irritating, easy to cause the body burns; phosphorus oxychloride, a highly toxic substance, water violent hair in the air smoke, hydrolyzed into phosphoric acid and hydrogen chloride, is very unstable, to operate a lot of trouble; trifluoroacetic acid is highly corrosive and irritant, can cause the body burns; low yield of the reaction (10%). Seeking a simple operation, high reaction yield, low cost and suitable for industrial production production process 1- (3-methyl-1-phenyl-5-pyrazolyl) piperazine has a very important role in the field of medicine.

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since the capture is staggered, compd 165 is not clear in above pic see below

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if above section iis not clear see at ……..http://www.allfordrugs.com/2015/07/03/teneligliptin/

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CN104177295

reaction scheme in   http://www.google.com/patents/CN104177295A?cl=en

Description: LR as Lawesson reagent (Lawesson Reagent), is a sulfur oxygen exchange reagent. The present invention provides a method for preparing key intermediates Ge Lieting method, comprising the steps of: (I) N-Boc-N- acetoacetyl piperazine Lawesson’s reagent in the presence of an organic solvent, with a phenylhydrazine of the formula occurs ⑴ reaction shown:

(2) the step (1) The product was dissolved in an organic solvent, the following formula (II) in concentrated hydrochloric acid to deprotected shown:

GOSOGLIPTIN

CAS 869490-23-3 FREE BASE

DIHYDROCHLORIDE..869490-47-1

GOSOGLIPTIN; UNII-GI718UO477;  PF-00734200; PF-734200;

(3,3-difluoropyrrolidin-1-yl)-[(2S,4S)-4-(4-pyrimidin-2-ylpiperazin-1-yl)pyrrolidin-2-yl]methanone

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PAPER

New synthetic route to a dipeptidyl peptidase-4 inhibitor
Org Process Res Dev 2012, 16(3): 409

http://pubs.acs.org/doi/abs/10.1021/op200309z

A new synthetic route to a dipeptidyl peptidase-4 (DPP4) inhibitor was developed and demonstrated on a multigram scale. This approach takes advantage of the cheap and readily available Boc-trans-4-hydroxy-l-proline methyl ester as starting material which was derivatized through an SN2 reaction. Several leaving groups were studied, and the nosylate group showed superiority over other derivatives. Formation of an amide using the most costly starting material, 3,3-difluoropyrrolidine, was performed late in the synthesis to minimize its economical impact on the overall cost of the API.

(3,3-Difluoropyrrolidin-1-yl)-(2S,4S)-4-(4-(pyrimidin-2-yl)piperazin-1-yl)pyrrolidin-2-yl)methanone.FREE BASE

Mp 149 °C (decomp).

[α]d = −31.1 (T = 24 °C, c = 1, CHCl3). Specific rotation of product 4 prepared using the initial route: [α]d = −31.5 (T = 24 °C, c = 1, CHCl3). 

1H NMR (400 MHz; CDCl3) δ 8.30 (d, J = 4 Hz, 2H), 6.48 (t, J = 4 Hz, 1H), 3.95–3.6 (m, 9H), 3.25–2.85 (m, 4H), 2.6–2.25 (m, 7H), 1.75–1.6 (m, 1H). 

13C NMR (100 MHz; CDCl3) δ 172.28; 161.55; 157.70; 127.22 (t, 1J C–F = 248 Hz), 126.22 (t, 1J C–F = 246 Hz), 109.95; 66.54; 58.87; 57.99; 52.71 (t, 2 J C–F = 32 Hz); 52.00; 50.41; 43.03; 34.46, 34.37, 34.25; 19F NMR (377 MHz, CDCl3) δ −102.1 (m, 2F).

IR (neat): 2951w, 2864w, 2799w, 2759w, 1630s, 1585vs, 1547m, 1449m, 1172m, 1254m, 1129m, 982w, 923m, 796m, 638w.

HRMS (ES, N2) Calcd for C17H24F2N6O: 367.20524, found: 367.20592.

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PAPER

(3,3-difluoro-pyrrolidin-1-yl)-((2S,4S)-(4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidin-2-yl)-methanone: A potent, selective, orally active dipeptidyl peptidase IV inhibitor
Bioorg Med Chem Lett 2009, 19(7): 1991

 http://www.sciencedirect.com/science/article/pii/S0960894X09001966?np=y

• Pfizer Global Research & Development, Groton/New London Laboratories, Pfizer Inc, Groton, CT 06340, United States

SEE………….https://docs.google.com/viewer?url=http%3A%2F%2Fwww.sciencedirect.com%2Fscience%2FMiamiMultiMediaURL%2F1-s2.0-S0960894X09001966%2F1-s2.0-S0960894X09001966-mmc1.doc%2F271398%2Fhtml%2FS0960894X09001966%2Fce1f70bd989d6d4b79b40c26570693d2%2Fmmc1.doc

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PATENT

WO 2005116014

http://www.google.co.in/patents/WO2005116014A1?cl=en

Example 113 (3.3-Difluoropyrrolidin-1-yl)-((2S,4S)-4-(4-(pyrimidin-2-yl)piperazin-1-yl)pyrrolidin-2-yl)-methanone

Step 1 – (S)-2-(3.3-Difluoro-pyrrolidine-1-carbonyl)-4-oxo-pyrrolidine-1 -carboxylic acid tert-butyl ester

(S)-4-Oxo-pyrrolidine-1 ,2-dicarboxylic acid 1-tert-butyl ester (6.6 kg, 1.0 equivalent) was charged to a reactor, followed by addition of dichloromethane (15 volumes). The reaction mixture was cooled to 0°C. Triethylamine (4.82 liters, 1.2 equiv) was added over 30 minutes. The mixture turned from suspension to a clear solution at the end of triethylamine addition. The mixture was held at 0°C to 5°C for 10 minutes. Pivaloyl chloride (3.65 kg, 1.05 equivalents) was added slowly while keeping the reaction temperature at 0°C to 5°C. The reaction mixture turned back to aslurry. The reaction mixture was sampled for completion by HPLC (using diethylamine to derivatize) after held for 1 hour at 0°C to 5°C.

3,3-Difluoro- pyrrolidine hydrochloride (4.13 kg, 1.0 equivalent) was charged to the above mixture over 10 minutes at – 10°C to 0°C. Triethylamine (4.0 liters, 1.0 equiv) was introduced slowly over 70 minutes at -10°C to 0°C. Upon completion of triethylamine addition, the mixture was stirred for 1h at 0 to 5°C. The reaction was complete by HPLC assay (-1% starting material). The reaction was quenched with water (10 volumes) at 0°C to 5 °C. The mixture was heated to 20°C to 25 °C. The layers were separated, and the organic layer was washed with 0.5 M HCI (5 volumes). The organic layer was again washed with combined 5% NaHC0₃ (2 volumes) and half saturated brine solution (1.64 M, 3 volumes). The organic solution was concentrated atmospherically to a low stirrable volume (approximately 20 liters). Ethyl acetate (12.6 volumes, 82.8 liters) was added, the solution was concentrated atmospherically to -6 volumes. The mixture was held at 60°C to 65 °C for 2 hours and cooled to room temperature over 3 hours. The mixture was held at 20°C to 25 °C for 8 hours. Heptane (8 volumes) was added, and the mixture was granulated for a minimum of 2 hours. The solid was filtered, rinsed with 2:1 heptane/ethyl acetate (1 volume), and dried in a tray dryer at 25°C to 35°C for a minimum of 12 h. Yield: 7.26 kg, 79%. HPLC purity: 99.7%. The mother liquor (86 liters) was concentrated to 12 liters under partial vacuum at 65°C to 70°C. The mixture was cooled to 60°C to 65 °C. Ethyl acetate (4.0 liters) was added slowly over 15 minutes. The mixture was cooled to 20°C to 25 °C over 2 hours and was held at that temperature for at least 2 hours. The solid was filtered and rinsed with heptane/ethyl acetate (3:1 v/v, 1.7 liters). Drying in a tray dryer for 12 hours at 35°C to 45 °C yielded 435 grams of product. HPLC purity: 96.4%.

Step 2 – (2S.4S)-2-(3.3-Dif luoro-pyrrolidine-1 -carbonyl)-4-(4-pyrimidin-2-yl-piperazin-1 -yl)-pyrrolidine-1 – carboxylic acid tert-butyl ester A reactor was charged with THF (20 volumes), 2-piperazin-1-yl-pyrimidine (2.17 kg, 1.05 equivalents) and the product from Step 1 (4.00 kg, 1.0 equivalent). The mixture was held at 20°C to 25°C until all material was dissolved over 30 minutes. Acetic acid (0.792 kg, 1.05 equivalents) as added. The mixture was stirred for 1 hour during which the reaction mixture turned to cloudy. The reaction mixture was refluxed for 30 minutes and then concentrated at 60°C to 70°C until a steady temperature of 66.9°C was observed in the overheads indicating complete removal of water from the system. More THF was added as necessary. At the end, THF was added to bring the total volume in the reactor to 15 volumes of the limit reagent. The reaction mixture was cooled to -3°C to 7°C and sampled for complete formation of imine by HPLC (using sodium triacetoxyborohydride to reduce imine). Sodium triacetoxyborohydride (5.33 kg, 2.0 equivalents) was added portion-wise to the suspension at -5°C to 15°C. The reaction mixture was heated to 20°C to 25°C and held for 12 hours. HPLC results confirmed the reaction was complete by 99.8%. Sodium bicarbonate aqueous solution (10% w/w, 10 volumes) was added. The slurry was concentrated to remove 10 volumes of THF under partial vacuum at 30°C to 60°C. Ethyl acetate (10 volumes) was added to the suspension after it cooled to 20°C to 25^CC. The organic phase was separated and the aqueous phase was checked by HPLC. It contained less than 2% of the product. The organic phase was washed with water (5 volumes), saturated brine solution (5 volumes) and concentrated to a small volume (2 volumes) under partial vacuum at 45°C to 50°C. To the slurry was added heptane (10 volumes) at 45°C to 50°C over 30 minutes. The mixture was cooled to 20°C to 25°C and granulated for 2 hours. Solid was collected by filtration, rinsed with heptane (2 volumes). Drying in a tray dryer for 12 hours at 35°C to 45°C yield 5.35 kg (91.3%) of the product. Step 3 – (3.3-Dif luoro-pyrrolidin-1 -yl)-f(2S.4S)-4-(4-pyrimidin-2-yl-piperazin-1 -yl)-pyrrolidin-2-yll- methanone Water (19 liters, 2 volumes) was charged to a reactor followed by the product from Step 2 (9.57 kg,

1.0 equivalent). To the slurry was added concentrated HCI (37 wt% in water, 19.1 liters, 2 volumes) slowly at 20°C to 30°C over 4 hours. The slurry went into solution after 12 liters of HCI was added. After the addition completion, the reaction was complete by HPLC assay. The reaction mixture was cooled to 5°C to 15°C. To the mixture was added 50% NaOH aqueous solution slowly with agitation to pH 10 to pH 11. The pH was monitored with a pH meter closely during the neutralization. The total volume of 50% NaOH added was 12.45 liters. The mixture was warmed to 20°C to 25°C and extracted with ethyl acetate twice (115 liters, 12 volumes and 57 liters, 6 volumes, respectively). The sample from aqueous layer after second extraction was analyzed by HPLC and showed only 1% of the product in that aqueous solution.

The organic layers were combined and treated with magnesium sulfate (5 kg) for 1 hour. The mixture was filtered. The filter cake was rinsed with ethyl acetate (10 liters). The filtrate was charged back to the reactor via a 0.2 micron in-line filter for speck free operation. (The following operations were performed under speck free conditions.) The solution was concentrated to 20 liters (2 volumes) under partial vacuum at 50°C to 60°C. The mixture was cooled to 20°C to 25°C over 30 minutes. Upon cooling to room temperature, crystallization occurred. The mixture was held for 30 minutes. Hexanes (20 liters, 2 volumes) was added slowly over 1 hour. The mixture was granulated for 2 hours. The solid product was collected by filtration and rinsed with hexanes/ethyl acetate (10 liters, 1 :1 v/v). The filter was blown dry with nitrogen for a minimum of 2 hours. The product was dried in a tray dryer at 44°C for 12 hours.

Yield: 5.7 kg, 75.9%.

m.p. 156°C. MS m/z 367 (MH⁺).

FREE BASE

¹H NMR (400 MHz, D₂0): δ 8.15 (d, 2H, J = 5.0 Hz, CH of pyrimidine), 6.55 (t, 1 H, J = 4.8 Hz, CH of pyrimidine), 3.87-3.81 (dd, 1 H, H_2b of proline, rotomeric), 3.78-3.50 (m, 4H, N-CH₂ of pyrrolidide), 3.55-3.40 (m, 4H, N-CH₂ of piperazine), 2.97 (dd, 1 H, J = 10.2, 6.6 Hz, H_5a of proline), 2.85-2.75 (m, 1 H, H_4b of proline), 2.69 (dd, 1 H, J = 10.0, 9.1 Hz, H_5b of proline), 2.55-2.20 (m, 7H, overlapping N-CH₂ of piperazine, CH₂ of pyrrolidide and H_3b of proline), 1.47-1.38 (m, 1 H, H_3a of proline).

Alternatively, the dihydrochloride salt of the titled compound was prepared according to the method of Example 1.

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US 2005/0256310

http://www.google.com/patents/US20050256310

This approach begins with N–t-Boc-4-oxo-l-proline (1) that undergoes a mixed anhydride activation with pivaloyl chloride at 0 °C, followed by amidation with 3,3-difluoropyrrolidine to yield the intermediate 2. Reductive amination with 1-(2-pyrimidyl)piperazine using sodium triacetoxyborohydride in THF/AcOH provided the desired stereoisomer 3 in high yield and selectivity, the undesired diastereomer being completely removed by crystallization. Deprotection of 3 with 6 N HCl, followed by neutralization with 50% NaOH and extraction provided PF-734200 (4) in good yield.

EXAMPLE 113 (3,3-Difluoropyrrolidin-1-yl)-((2S,4S)-4-(4-(pyrimidin-2-yl)piperazin-1-yl)pyrrolidin-2-yl)-methanone

Step 1—(S)-2-(3,3-Difluoro-pyrrolidine-1-carbonyl)-4-oxo-pyrrolidine-1-carboxylic acid tert-butyl

(S)-4-Oxo-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester (6.6 kg, 1.0 equivalent) was charged to a reactor, followed by addition of dichloromethane (15 volumes). The reaction mixture was cooled to 0° C. Triethylamine (4.82 liters, 1.2 equiv) was added over 30 minutes. The mixture turned from suspension to a clear solution at the end of triethylamine addition. The mixture was held at 0° C. to 5° C. for 10 minutes. Pivaloyl chloride (3.65 kg, 1.05 equivalents) was added slowly while keeping the reaction temperature at 0° C. to 5° C. The reaction mixture turned back to a slurry. The reaction mixture was sampled for completion by HPLC (using diethylamine to derivatize) after held for 1 hour at 0° C. to 5° C. 3,3-Difluoro-pyrrolidine hydrochloride (4.13 kg, 1.0 equivalent) was charged to the above mixture over 10 minutes at −10° C. to 0° C. Triethylamine (4.0 liters, 1.0 equiv) was introduced slowly over 70 minutes at −10° C. to 0° C. Upon completion of triethylamine addition, the mixture was stirred for 1 h at 0 to 5° C. The reaction was complete by HPLC assay (˜1% starting material). The reaction was quenched with water (10 volumes) at 0° C. to 5 ° C. The mixture was heated to 20° C. to 25 ° C. The layers were separated, organic layer was washed with 0.5 M HCl (5 volumes). The organic layer was again washed with combined 5% NaHCO₃ (2 volumes) and half saturated brine solution (1.64 M, 3 volumes). The organic solution was concentrated atmospherically to a low stirrable volume (approximately 20 liters). Ethyl acetate (12.6 volumes, 82.8 liters) was added, the solution was concentrated atmospherically to ˜6 volumes. The mixture was held at 60° C. to 65° C. for 2 hours and cooled to room temperature over 3 hours. The mixture was held at 20° C. to 25 ° C. for 8 hours. Heptane (8 volumes) was added, and the mixture was granulated for a minimum of 2 hours. The solid was filtered, rinsed with 2:1 heptane/ethyl acetate (1 volume), and dried in a tray dryer at 25° C. to 35° C. for a minimum of 12 h. Yield: 7.26 kg, 79%. HPLC purity: 99.7%. The mother liquor (86 liters) was concentrated to 12 liters under partial vacuum at 65° C. to 70° C. The mixture was cooled to 60° C. to 65° C. Ethyl acetate (4.0 liters) was added slowly over 15 minutes. The mixture was cooled to 20° C. to 25° C. over 2 hours and was held at that temperature for at least 2 hours. The solid was filtered and rinsed with heptane/ethyl acetate (3:1 v/v, 1.7 liters). Drying in a tray dryer for 12 hours at 35° C. to 45° C. yielded 435 grams of product. HPLC purity: 96.4%.

Step 2—(2S,4S)-2-(3,3-Difluoro-pyrrolidine-1-carbonyl)-4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidine-1-carboxylic acid tert-butyl ester

A reactor was charged with THF (20 volumes), 2-piperazin-1-yl-pyrimidine (2.17 kg, 1.05 equivalents) and the product from Step 1 (4.00 kg, 1.0 equivalent). The mixture was held at 20° C. to 25° C. until all material was dissolved over 30 minutes. Acetic acid (0.792 kg, 1.05 equivalents) as added. The mixture was stirred for 1 hour during which the reaction mixture turned to cloudy. The reaction mixture was refluxed for 30 minutes and then concentrated at 60° C. to 70° C. until a steady temperature of 66.9° C. was observed in the overheads indicating complete removal of water from the system. More THF was added as necessary. At the end, THF was added to bring the total volume in the reactor to 15 volumes of the limit reagent. The reaction mixture was cooled to −3° C. to 7° C. and sampled for complete formation of imine by HPLC (using sodium triacetoxyborohydride to reduce imine). Sodium triacetoxyborohydride (5.33 kg, 2.0 equivalents) was added portion-wise to the suspension at −5° C. to 15° C. The reaction mixture was heated to 20° C. to 25° C. and held for 12 hours. HPLC results confirmed the reaction was complete by 99.8%. Sodium bicarbonate aqueous solution (10% w/w, 10 volumes) was added. The slurry was concentrated to remove 10 volumes of THF under partial vacuum at 30° C. to 60° C. Ethyl acetate (10 volumes) was added to the suspension after it cooled to 20° C. to 25° C. The organic phase was separated and the aqueous phase was checked by HPLC. It contained less than 2% of the product. The organic phase was washed with water (5 volumes), saturated brine solution (5 volumes) and concentrated to a small volume (2 volumes) under partial vacuum at 45° C. to 50° C. To the slurry was added heptane (10 volumes) at 45° C. to 50° C. over 30 minutes. The mixture was cooled to 20° C. to 25° C. and granulated for 2 hours. Solid was collected by filtration, rinsed with heptane (2 volumes). Drying in a tray dryer for 12 hours at 35° C. to 45° C. yield 5.35 kg (91.3%) of the product.

Step 3—(3,3-Difluoro-pyrrolidin-1-yl)-[(2S,4S)-4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidin-2-yl]-methanone

Water (19 liters, 2 volumes) was charged to a reactor followed by the product from Step 2 (9.57 kg, 1.0 equivalent). To the slurry was added concentrated HCl (37 wt % in water, 19.1 liters, 2 volumes) slowly at 20° C. to 30° C. over 4 hours. The slurry went into solution after 12 liters of HCl was added. After the addition completion, the reaction was complete by HPLC assay. The reaction mixture was cooled to 5° C. to 15° C. To the mixture was added 50% NaOH aqueous solution slowly with agitation to pH 10 to pH 11. The pH was monitored with a pH meter closely during the neutralization. The total volume of 50% NaOH added was 12.45 liters. The mixture was warmed to 20° C. to 25° C. and extracted with ethyl acetate twice (115 liters, 12 volumes and 57 liters, 6 volumes, respectively). The sample from aqueous layer after second extraction was analyzed by HPLC and showed only 1% of the product in that aqueous solution. The organic layers were combined and treated with magnesium sulfate (5 kg) for 1 hour. The mixture was filtered. The filter cake was rinsed with ethyl acetate (10 liters). The filtrate was charged back to the reactor via a 0.2 micron in-line filter for speck free operation. (The following operations were performed under speck free conditions.) The solution was concentrated to 20 liters (2 volumes) under partial vacuum at 50° C. to 60° C. The mixture was cooled to 20° C. to 25° C. over 30 minutes. Upon cooling to room temperature, crystallization occurred. The mixture was held for 30 minutes. Hexanes (20 liters, 2 volumes) was added slowly over 1 hour. The mixture was granulated for 2 hours. The solid product was collected by filtration and rinsed with hexanes/ethyl acetate (10 liters, 1:1 v/v). The filter was blown dry with nitrogen for a minimum of 2 hours. The product was dried in a tray dryer at 44° C. for 12 hours.

Yield: 5.7 kg, 75.9%. m.p. 156° C. MS m/z 367 (MH⁺).

¹H NMR (400 MHz, D₂O): δ 8.15 (d, 2H, J=5.0 Hz, CH of pyrimidine), 6.55 (t, 1H, J=4.8 Hz, CH of pyrimidine), 3.87-3.81 (dd, 1H, H_2b of proline, rotomeric), 3.78-3.50 (m, 4H, N—CH₂ of pyrrolidide), 3.55-3.40 (m, 4H, N—CH₂ of piperazine), 2.97 (dd, 1H, J=10.2, 6.6 Hz, H_5a of proline), 2.85-2.75 (m, 1H, H_4b of proline), 2.69 (dd, 1H, J=10.0, 9.1 Hz, H_5b of proline), 2.55-2.20 (m, 7H, overlapping N—CH₂ of piperazine, CH₂ of pyrrolidide and H_3b of proline), 1.47-1.38 (m, 1H, H_3a of proline).

Alternatively, the dihydrochloride salt of the titled compound was prepared according to the method of Example 1.

……………..

PAPER

if image is not clear see at………..http://www.allfordrugs.com/2015/07/03/gosogliptin/

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see gliptins at…………http://drugsynthesisint.blogspot.in/p/gliptin-series.html

EVOGLIPTIN
CAS: 1222102-29-5 FREE

HCL……1246960-27-9

tartare.. 1222102 -51-3

Dong-A Pharmaceutical. Co., Ltd, 동아제약 주식회사
2-Piperazinone, 4-((3R)-3-amino-1-oxo-4-(2,4,5-trifluorophenyl)butyl)-3-((1,1-dimethylethoxy)methyl)-, (3R)-
R)-4-((R)-3-Amino-4-(2,4,5-trifluorophenyl)-butanoyl)-3-(t-butoxymethyl)-piperazin-2-one

4-[3(R)-Amino-4-(2,4,5-trifluorophenyl)butyryl]-3(R)-(tert-butoxymethyl)piperazin-2-one hydrochloride

DA-1229

see…http://www.allfordrugs.com/2015/07/03/evogliptin/

DA-1229 is a dipeptidyl peptidase IV (CD26) inhibitor currently being developed in phase III clinical studies at Dong-A for the treatment of type 2 diabetes.

In 2014, Eurofarma aquired rights for product development and commercialization in Brazil.

If above image is not clear then see at…….http://www.allfordrugs.com/2015/07/03/evogliptin/

86…………H. J. Kim, W. Y. Kwak, J. P. Min, J. Y. Lee, T. H. Yoon, H. D. Kim, C. Y. Shin, M. K.
Kim, S. H. Choi, H. S. Kim, E. K. Yang, Y. H. Cheong, Y. N. Chae, K. J. Park, J. M.
Jang, S. J. Choi, M. H. Son, S. H. Kim, M. Yoo and B. J. Lee, Bioorg. Med. Chem. Lett.,
2011, 21 (12), 3809-3812.
[87] …………K. S. Lim, J. Y. Cho, B. H. Kim, J. R. Kim, H. S. Kim, D. K. Kim, S. H. Kim, H. J. Yim,
S. H. Lee, S. G. Shin, I. J. Jang and K. S. Yu, Br. J. Clin. Pharmacol., 2009, 68 (6), 883-
890.

…………………………………..

WO 2010114291

http://www.google.co.in/patents/WO2010114291A2?cl=en

Formula 1

Korea Patent Publication No. 2008-0094604 the call to the scheme, as indicated by A Ⅰ) of formula (II) beta-compound of formula 3 is already substituted heterocyclic compound having 1-hydroxy-benzotriazole group (HOBT) 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide (EDC) and reacting with a tertiary amine to prepare a compound of formula (4) connected by peptide bonds; Ⅱ) beta comprises the step of reacting under acidic conditions a compound of the formula (4) – a method of manufacturing the heterocyclic compounds of the formula I having an amino group is disclosed.

– Scheme A]

(Wherein, PG is a protecting group.)

In this case, the beta of the formula (2) of Scheme A – a compound having an amino group is prepared in addition to the DPP-IV inhibitor International Publication represented by Formula 1 WO03 / 000181, WO03 / 004498, WO03 / 082817, WO04 / 007468, WO04 / 032836, WO05 / 011581, WO06 / 097175, WO07 / 077508, WO07 / 063928, WO08 / 028662 WO08 / it may be used for the production of different DPP-IV inhibitors according 087,560 and can be prepared in a number of ways.

To, the compound of Formula 2 is an example as shown in Scheme J. Med.Chem. 2005; 141, and Synthesis 1997; it can be produced by the known method described in 873.

Specifically, (2S) – (+) – 2,5- dihydro-3,6-dimethoxy-2-isopropyl-pyrazine 2,4,5-trifluoro-react with benzyl bromide and acid treatment, and then the amine an ester compound obtained by the protection reaction. Ester compounds are hydrolyzed to re-3- (2,4,5-trifluoro-phenyl) -2-amino-propionic acid tert such as isobutyl chloroformate, triethylamine or diisopropylethylamine to give the amine, and then using diazomethane to form a diazo ketone, and then may be prepared by reaction with silver benzoate. However, the reaction can be performed at low temperature (-78 ℃) or high alpha-amino acid to purchase and use, and may have a risk of problems such as the need to use large diazomethane.

To a different process for preparing a compound of Formula 2 as shown in scheme Tetrahedron: Asymmetry 2006; It is known in 2622; 205 or similarly Bioorganic & Medicinal Chemistry Letters 2007.

That is, a 1,1′-carbonyl-2,4,5 which the phenyl trifluoroacetic acid activated using the following imidazole mono-methyl words potassium carbonate is reacted with the beta-keto ester compound is prepared. This produced an enamine ester using ammonium acetate and ammonium solution, the ester compound chloro (1,5-cyclooctadiene) rhodium (I) dimer using a chiral ferrocenyl ligands I the reaction of the high-pressure hydrogen with a chiral primary amine with a beta-amino ester compound after production and can lead to hydrolysis to prepare a compound of formula (2). However, use of expensive metal catalyst has a problem that must be performed in high pressure hydrogenation.

The method for preparing a compound of Formula 2 is disclosed in International Publication No. WO 04/87650.

Specifically, 2,4,5-fluorophenyl reagent is oxalyl chloride, the acid activated acid with 2,2-dimethyl-1,3-dioxane-4,6-dione, and after the reaction of methanol and the resulting material at reflux to prepare a corresponding compound. With a selective reducing reagents which enantiomers (S) -BINAP-RuCl ₂ and hydrogen through a reaction (S) – producing a compound having coordinated to each other, it again after the decomposition, and the singer O- benzyl hydroxyl amine and the coupling reaction and the intermediate is prepared. To do this, the resulting intermediate tree azodicarboxylate and diisopropyl azodicarboxylate presence ring condensation reaction, treated with an aqueous solution of lithium hydroxide to (R) – while having the formula (II) coordinated to the amine group protected with a benzyl-O- the compound can be produced. However, the method has a problem as a whole to be prepared by the reaction yield to be low and a long processing time to perform the reaction.

Thus, the conventional known method for producing a compound of the general formula (2) has the disadvantage of using expensive reagents, or not suitable for commercial mass-production method by a long synthesis time yield is also low.

In addition, the compound represented by General Formula (3), as described in Korea Patent Publication No. 2008-0094604 call, can be prepared by way of reaction schemes.

Specifically, the starting material D- serine methyl ester is substituted by a hydroxy group when reflux again substituted by trityl chloride as methoxy groups converted to the aziridine compound.

[Scheme 3]

………………………………

WO 2010114292

http://www.google.com/patents/WO2010114292A2?cl=en

…………………………………

Discovery of DA-1229: a potent, long acting dipeptidyl peptidase-4 inhibitor for the treatment of type 2 diabetes
Bioorg Med Chem Lett 2011, 21(12): 3809

http://www.sciencedirect.com/science/article/pii/S0960894X11004859

A series of β-amino amide containing substituted piperazine-2-one derivatives was synthesized and evaluated as inhibitors of dipeptidyl pepdidase-4 (DPP-4) for the treatment of type 2 diabetes. As results of intensive SAR study of the series, (R)-4-[(R)-3-amino-4-(2,4,5-trifluorophenyl)-butanoyl]-3-(t-butoxymethyl)-piperazin-2-one (DA-1229) displayed potent DPP-4 inhibition pattern in several animal models, was selected for clinical development.

 http://www.luye.cn/en/uploads//2014-07/21/_1405936452_zr21xh.pdf

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see gliptins at…..http://drugsynthesisint.blogspot.in/p/gliptin-series.html

Dong-A Pharm. Co., Ltd, Yongin-si, Gyeonggi-do, Republic of Korea.

1  TRELAGLIPTIN

GEMIGLIPTIN

1-[2(S)-Amino-4-[2,4-bis(trifluoromethyl)-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidin-7-yl]-4-oxobutyl]-5,5-difluoropiperidin-2-one

PHASE 3, DPP-IV inhibitor, Lg Life Sciences Ltd.

CAS 911637-19-9

Mol. Formula:   C18H19F8N5O2

Gemigliptin (rINN), previously identified as LC15-0444, is an oral anti-hyperglycemic agent (anti-diabetic drug) of the new dipeptidyl peptidase-4 (DPP-4) inhibitor class of drugs.^[1] It is well known that glucose lowering effects of DPP-4 inhibitors are mainly mediated by GLP-1 and gastric inhibitory polypeptide (GIP) incretin hormones which are inactivated by DPP-4.

Gemigliptin was initially developed solely by LG Life Sciences. In 2010, Double-Crane Pharmaceutical Co. (DCPC) joined with LGLS to co-develop the final compound and collaborate on the marketing of the drug in China. LGLS also announced on Nov., 2010 that NOBEL Ilac has been granted rights to develop and commercialize gemigliptin in Turkey.

Gemigliptin, a dipeptidyl peptidase IV (CD26; DPP-IV; DP-IV) inhibitor, is currently undergoing phase III clinical trials at LG Life Sciences as an oral treatment for type II diabetes. The company is also testing the compound in phase II/III clinical studies for the treatment of patients with cisplatin-induced acute kidney injury.

DPP IV inhibitors have glucose-lowering effects mediated by GLP-1 incretin hormone which is inactivated by DPP IV. In 2010, gemigliptin was licensed to Beijing Double-Crane Pharmaceutical by LG Life Sciences for distribution and supply in China for the treatment of type 2 diabetes.

A New Drug Application (NDA) for gemigliptin in the treatment of type 2 diabetes was submitted to the Korea Food & Drug Administration (KFDA) in July 2011. Then on June 27, 2012, the KFDA has approved the manufacture and distribution of LG Life Sciences’ diabetes treatment, Zemiglo, the main substance of which is gemigliptin. Clinical trials for evaluating the safety and efficacy of gemigliptin in combination with metformin have been completed.

…………

Efficient synthesis of gemigliptin, a potent and selective DPP-4 inhibitor for the treatment of type 2 diabetes mellitus, has been developed. Gemigliptin were prepared from two key API starting materials, DP18 and DP57, in 75~80% yield and >99% purity over three steps under the GMP control: coupling, deprotection of N-Boc group, and final crystallization with L-tartaric acid. All steps were conducted in the same solvent system and the intermediates were isolated by simple filtration without distillation of solvent. The established process was validated obviously through the three consecutive batches for a commercial production.

………..IN CASE IMAGES NOT VISIBLE …….SEE THIS AT ………http://www.allfordrugs.com/2015/07/06/gemigliptin/

GO TO MY OTHER SITE FOR SYNTHESIS

(3S)-3-amino-4-(5,5-difluoro-2-oxopiperidino)-1-[2,4-di(trifluoromethyl)-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidin-7-yl]butan-1-one
Clinical data
Routes of administration	Oral
Pharmacokinetic data
Bioavailability	94% (rat), 73% (dog), 26% (monkey)
Biological half-life	3.6 h (rat), 5.2 h (dog), 5.4 h (monkey)
Identifiers
CAS Registry Number	911637-19-9
ATC code	A10BH06
PubChem	CID: 11953153
ChemSpider	10127461
UNII	5DHU18M5D6
Synonyms	LC15-0444
Chemical data
Formula	C18H19F8N5O2
Molecular mass	489.36 g/mol

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History

The NDA for gemigliptin was submitted to KFDA in July, 2011 and it was approved on June 27, 2012. By the end of 2012, gemigliptin will be marketed in Korea as Zemiglo which is the fifth new DPP-4 inhibitor diabetes treatment in the world.

Mechanism of action

DPP-4 is a serine protease located on the cell surfaces throughout the body. In plasma, DPP-4 enzyme rapidly inactivates incretins including GLP-1 and GIP which are produced in the intestine depending on the blood glucose level and contribute to the physiological regulation of glucose homeostatis. Active GLP-1 and GIP increase the production and release of insulin by pancreatinc beta cells. GLP-1 also reduces the scretion of glucacon by pancreatic alpha cells, thereby resulting in a decreased hepatic glucose production. However these incretins are rapidly cleaved by DPP-4 and their effects last only for a few minutes. DPP-4 inhibitors block the cleavage of the gliptins and thus lead to an increasee insulin level and a reduced glucagon level in a glucose-dependent way. This results in a decrease of fasting and postprandial glycemia, as well as HbA1c levels.^[2]

Preclinical studies

Gemigliptin is a competitive, reversible DPP-4 inhibitor (IC50 = 16 nM) with excellent selectivity over other critical human proteases such as DPP-2, DPP-8, DPP-9, elastase,trypsin, urokinase and cathepsin G. Gemigliptin was rapidly absorbed after single oral dosing and the compound was eliminated with a half-life of 3.6 h, 5.2 h, and 5.4 h in the rat, dog, and monkey, respectively.

The bioavailability of gemigliptin in the rat, dog, and monkey was species-dependent with the values of 94%, 73%, and 26%, respectively. Following the oral administration of gemigliptin in the rat, dog and monkey, about 80% inhibition of plasma DPP-4 activity were observed at the plasma levels of 18 nM, 14 nM and 4 nM, respectively.

In the diet-induced obese (DIO) mice, gemigliptin reduced glucose excursion during OGTT in a dose dependent manner with the minimum effective dose of 0.3 mg/kg and enhanced glucose-stimulated plasma GLP-1 increase in a dose dependent manner reaching the maximum effect at the dose of 1 mg/kg.

Following 4 week oral repeat dosing in the DIO mice, gemigliptin reduced significantly HbA1c with the minimum effective dose of 3 mg/kg. In the beagle dog, gemigliptin significantly enhanced active GLP-1, decreased glucagon, and reduced glucose excursion during OGTT following a single dosing.

Studies on animals suggest its positive effect on hepatic and renal fibrosis .^[3][4] Data on human patients are still inconclusive .^[5]

Clinical studies

The dose-range finding phase 2 study was performed and 145 patients (91men and 54 women) with type 2 diabetes mellitus were enrolled. All three doses (50,100 and 200 mg groups) of gemigliptin significantly reduced the HbA_1c from baseline compared to the placebo group without a significant difference between the doses.

Subjects with a higher baseline HbA_1c (≥8.5%) had a greater reduction in HbA_1c. Insulin secretory function, as assessed using homeostasis model assessment-beta cell, C-peptide and the insulinogenic index, improved significantly with gemigliptin treatment. Insulin sensitivity, as assessed using homeostasis model assessment-insulin resistance, also improved significantly after 12 weeks of treatment.

The 50 and 200 mg groups had significantly reduced total cholesterol and low-density lipoprotein cholesterol levels at 12 weeks compared to the placebo group.

The incidences of adverse events were similar in all study subjects. Gemigliptin monotherapy (50 mg for 12 weeks) improved the HbA_1c, FPG level, oral glucose tolerance testresults, β-cell function and insulin sensitivity measures, and was well tolerated in subjects with type 2 diabetes.

Results of Phase 3 clinical trials which have been finished recently will be updated near future.

…………..

WO 2006104356

 http://www.google.co.in/patents/WO2006104356A1?cl=en

EXAMPLE 83: Synthesis of l-(f2SV2-amino-4-r2.4-bisftrifluoromethylV5.8-dihvdropyridor3.4-d]pyrimidin-7f6H^‘)

-yl1-4-oxobutyll-5.5-difluoropiperidin-2-one [1960]

[1961] 21 mg of the title compound was obtained in a yield of 56% at the same manner as in EXAMPLE 1, except that 42 mg (0.071 mmol) of t-butyl

{(lS)-3-[2,4-bis(trifluoromethyl)-5,8-dihydropyrido[3,4-d]pyrimidin-7(6H)-yl]-l-[(5,5

-difluoro-2-oxpiperidin-l-yl)methyl]-3-oxpropyl}carbamate obtained in

PREPARATION 143 was used. [1962] ¹K NMR (CD₃OD) δ 5.05-4.92 (2H, m), 3.98-3.91 (2H, m), 3.85-3.79 (2H, m),

3.70-3.59 (2H, m), 3.54-3.48 (IH, m), 3.36-3.33 (2H, m), 3.24 (IH, bra), 3.14 (IH, bra), 2.83-2.76 (IH, m), 2.72-2.53 (3H, m), 2.43-2.34 (2H, m) [1963] Mass (m/e) 490 (M+l)

[1964]

[1965] PREPARATION 144: Synthesis of t-butyl

(riSV3-r2.4-bisrtrifluoromethylV5.8-dihvdropyridor3.4-d]pyrimidin-7r6HVyl]-l-(rr2 S)-2-methyl-5-oxomorpholin-4-yl1methyl 1 -3-oxpropyl 1 carbamate

[1966] 14 mg of the title compound was obtained in a yield of 17% at the same manner as in PREPARATION 45, except that 43.7 mg (0.138 mmol) of (3S)-3-[(t-butoxycarbonyl)amino]-4-[2(S)-2-methyl-5-oxomoφholin-4-yl]-butanoic acid obtained in PREPARATION 55 and 42.5 mg (0.138 mmol) of 2,4-bis(trifluoromethyl)-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidine hydrochloric acid salt (product of PREPARATION 127) were used.

[1967] ¹K NMR (CDCl₃) δ 5.85-5.83 (IH, m), 5.09-4.92 (IH, m), 4.95-4.78 (IH, m),

4.23-4.08 (3H, m), 4.04-3.76 (3H, m), 3.73-3.66 (IH, m), 3.46-3.38 (IH, m), 3.36-3.21 (2H, m), 3.18-3.10 (2H, m), 2.96-2.81 (IH, m), 2.61-2.50 (IH, m), 1.43-1.41 (9H, m), 1.28-1.24 (3H, m)

[1968] Mass (m/e) 470 (M+l-Boc)

…………..

WO 2012030106

https://www.google.com/patents/WO2012030106A2?cl=en

Reaction Scheme 1

PREPARATION 1: Synthesis of diethyl 2,2-difluoropentanedioate

To a solution of ethyl bromodifluoroacetate (33.2 g) in tetrahydrofuran (94.0 g) was added ethyl acrylate (8.2 g) and copper powder (10.9 g). After heating to 50℃, TMEDA (9.5 g) was added dropwise and the reaction mixture was then stirred for 3 hours at the same temperature. Upon disappearance of ethyl acrylate as the starting material, to the reaction solution was added methyl t-butyl ether (MTBE, 73.7 g) followed by addition of 10% aqueous ammonium chloride solution (49.8 g) dropwise, and the mixture was then stirred for 30 minutes. The remaining copper residue was removed by filtration through a celite, and methyl t-butyl ether (MTBE, 66.3 g) was added to separate the layers. The separated organic layer was washed successively with 10% aqueous NH₄Cl solution (66.3 g) and 3 N aqueous hydrochloric acid solution (99.6 g) in order and then distilled under reduced pressure to obtain 55.0 g of the desired title compound.

¹H NMR (400 MHz, CDCl₃) δ 1.26 (t, J=7.2 Hz, 3H), 1.37 (t, J=7.2 Hz, 3H), 2.37-2.49 (m, 2H), 2.55 (t, J=7.2 Hz, 2H), 4.16 (q, J=7.2 Hz, 2H), 4.29 (q, J=7.2 Hz, 2H).

PREPARATION 2: Synthesis of ethyl 4,4-difluoro-5-hydroxypentanoate

14.8 g of the compound obtained from the above Preparation 1 was diluted with ethanol (20.4 g) and tetrahydrofuran (69.1 g) and then cooled to 0℃. To this solution was slowly added sodium borohydride (NaBH₄, 3.5 g) stepwise while keeping the internal temperature below 30℃. After confirming completion of the reaction by ¹H NMR, the reaction solution was cooled to the temperature of 10℃ and 10% aqueous ammonium chloride solution (77.7 g) was slowly added. The remaining boron compound was filtered through celite, and the filtrate was distilled under reduced pressure to remove tetrahydrofuran. Then, ethyl acetate (105.2 g) was added to separate the layers, and the organic layer was distilled under reduced pressure to obtain 10.8 g of the title compound.

¹H NMR (400 MHz, CDCl₃) δ 1.23 (t, J=7.2 Hz, 3H), 2.15-2.29 (m, 2H), 2.49 (t, J=7.2 Hz, 2H), 3.69 (t, J=12.0 Hz, 2H), 4.12 (q, J=4.0 Hz, 2H).

EXAMPLE 1: Synthesis of ethyl 4,4-difluoro-5-{[(trifluoromethyl)sulfonyl]oxy}- pentanoate

To the solution of 10.8 g of the compound, as obtained from the above Preparation 2, dissolved in dichloromethane (100.2 g) was added pyridine (7.0 g), and then the mixture was cooled to -5.0℃. After completion of cooling, trifluoromethane sulfonic acid anhydride (20.1 g) was slowly added dropwise while keeping the reaction temperature below 6.3℃. After stirring the reaction solution for 30 minutes, 1.5 N hydrochloric acid solution was added dropwise at 0℃ to separate the layers. The aqueous layer as separated was back-extracted twice with dichloromethane (33.4 g), and the extracts were combined with the organic layer separated from the above and then distilled under reduced pressure to obtain 19.7 g of the title compound as a yellow oil.

¹H NMR (500 MHz, CDCl₃) δ 1.27 (t, J=7.2 Hz, 3H), 2.29-2.39 (m, 2H), 2.59 (t, J=7.6 Hz, 2H), 4.18 (q, J=7.2 Hz, 2H), 4.55 (t, J=11.6 Hz, 2H).

EXAMPLE 2-1: Synthesis of ethyl 4,4-difluoro-5-{[(nonafluorobutyl)sulfonyl]- oxy}pentanoate

To the solution of 100.0 g of the compound, as obtained from the above Preparation 2, dissolved in dichloromethane (300.0 ml) was added pyridine (65.7 g), and the mixture was then cooled to -10.0℃. After completion of cooling, nonafluorobutanesulfonic anhydride (477.4 g) was slowly added dropwise. After stirring the reaction solution for 3 hours, 1.0 N hydrochloric acid solution (300.0 ml) was added dropwise to separate the layers. The aqueous layer as separated was back extracted once with dichloromethane (500.0 ml), and the extracts were combined with the organic layer separated from the above and then distilled under reduced pressure to obtain 177.5 g of the title compound.

¹H NMR (500 MHz, CDCl₃) δ 1.26 (t, 3H, J=7.3 Hz), 2.30-2.36 (m, 2H), 2.58 (t, 2H, J=7.4 Hz), 4.16 (q, 2H, J=7.3 Hz), 4.57 (t, 2H, J=11 Hz).

EXAMPLE 2-2: Synthesis of ethyl 4,4-difluoro-5-{[(nonafluorobutyl)sulfonyl]- oxy}pentanoate

To the solution of 500.0 g of the compound, as obtained from the above Preparation 2, dissolved in dichloromethane (1000.0 ml) was added triethylamine (389.0 g), and the mixture was then cooled to 0℃. After completion of cooling, perfluorobutanesulfonyl chloride (948.80 g) was slowly added dropwise. The reaction solution was stirred for 3 hours at room temperature, distilled under reduced pressure, dissolved in methyl t-butyl ether (MTBE, 3000.0 ml) and then washed three times with water. The organic layer thus obtained was dehydrated with magnesium sulfate, filtered through a celite and then distilled under reduced pressure to obtain 960.0 g of the title compound.

EXAMPLE 3: Synthesis of methyl (2S)-2-[(tert-butoxycarbonyl)amino]-4-oxo- pentanoate

To 25.0 g of the starting material, (3S)-3-[(t-butoxycarbonyl)amino]-4-oxo- pentanoic acid, was added t-butanol (96.9 g) followed by the addition of Boc₂O (25.4 g) and dimethylaminopyridine (DMAP, 62.0 g, 0.5 mol%) at room temperature, and the reaction mixture was then stirred for 23 hours at 40℃. Upon completion of the reaction, ethylene dichloride (62.3 g) in t-butanol was added, and the mixture was then distilled under reduced pressure to obtain 30.7 g of the title compound.

¹H NMR (400 MHz, CDCl₃) δ 1.45 (s, 9H), 1.47 (s, 9H), 2.71 (dd, J=4.8, 16.4 Hz, 1H), 2.88 (dd, J=4.4, 16.4 Hz, 1H), 3.75 (s, 3H), 4.53 (m, 1H), 5.44 (br d, J=8.0 Hz, 1H).

EXAMPLE 4: Synthesis of tert-butyl (3S)-3-[(tert-butoxycarbonyl)amino]-4-hydroxy- butanoate

30.7 g of the compound obtained from the above Example 3 was dissolved in ethanol (112.3 g) and, after lowering the internal temperature to 10.5℃ sodium borohydride (NaBH₄, 5.7 g) was slowly added dropwise. This reaction solution was stirred while maintaining the temperature below 22℃. After confirming completion of the reaction by ¹H NMR and TLC, to the reaction solution was slowly added 3.0 N hydrochloric acid solution (30.7 g) dropwise at the internal temperature of 10℃ followed by addition of diluted 0.2% hydrochloric acid solution (100.0 g). The reaction solution was adjusted to pH 3~4 with addition of 9.0% aqueous hydrochloric acid solution, and then back-extracted twice with ethyl acetate (100.0 g) and toluene (44.0 g). The organic layer thus obtained was distilled under reduced pressure to obtain 25.1 g of the title compound.

¹H NMR (500 MHz, CDCl₃) δ 1.44 (s, 9H), 1.45 (s, 9H), 2.48-2.57 (m, 2H), 3.69 (d, J=4.9 Hz, 1H), 3.97 (m, 1H), 5.22 (bs, 1H).

EXAMPLE 5: tert-butyl (3S)-[(tert-butoxycarbonyl)amino]-4-[(methylsulfonyl)oxy]- butanoate

To 25.1 g of the compound obtained from the above Example 4 was added dichloromethane (133.0 g) and triethylamine (148.0 g), and the mixture was then cooled to 0℃. To this reaction solution was slowly added methanesulfonyl chloride (11.8 g) diluted with dichloromethane (39.9 g) dropwise for 50 minutes while maintaining the internal temperature below 12℃. After completion of the reaction, the reaction solution was washed with 0.5 N aqueous hydrochloric acid solution (120.0 g) and water (100.4 g), and then distilled under reduced pressure to obtain 31.5 g of the title compound.

¹H NMR (500 MHz, CDCl₃) δ 1.44 (s, 9H), 1.46 (s, 9H), 2.62 (d, J=6.0 Hz, 2H), 3.04 (s, 3H), 4.21 (m, 1H), 4.30 (d, J=5.2 Hz, 2H), 5.16 (br d, J=7.2 Hz, 1H).

EXAMPLE 6: Synthesis of tert-butyl (3S)-4-azido-3-[(tert-butoxycarbonyl)amino]- butanoate

Sodium azide (NaN₃, 11.6 g) was diluted with dimethylacetamide (DMAc, 260.0 g). After elevating the internal temperature to 80℃, a solution of 31.5 g of the compound, as obtained from the above Example 5, diluted with dimethylacetamide (DMAc, 45.0 g) was added thereto. The reaction proceeded at 80℃ for 2 hours. To the reaction solution were added toluene (251.0 g) and water (320.0 g) to separate the layers. The organic layer thus obtained was distilled under reduced pressure to obtain 24.0 g of the title compound.

¹H NMR (500 MHz, CDCl₃) δ 1.47 (s, 9H), 1.49 (s, 9H), 2.49 (d, J=6.0 Hz, 2H), 3.44-3.55 (m, 2H), 4.09 (br s, 1H), 5.14 (br s, 1H).

EXAMPLE 7: Synthesis of tert-butyl (3S)-4-amino-3-[(tert-butoxycarbonyl)amino]- butanoate

To 21.0 g of the compound obtained from the above Example 6 was added tetrahydrofuran (93.3 g) followed by the addition of triphenylphosphine (PPh₃, 21.0 g) at 40℃, the mixture was stirred for 2 hours at the same temperature, and water (3.8 g) was then added thereto. The reaction solution was distilled under reduced pressure, and the resulting triphenylphosphine oxide solid was diluted with toluene (26.0 g) and n-hexane (41.0 g), and then filtered off. The filtrate was adjusted to pH 2~3 with 1.0 N aqueous hydrochloric acid solution (110.0 g) and then subjected to separation of the layers. To remove any residual triphenylphosphine oxide solid, the aqueous layer obtained above was washed with dichloromethane (100.0 g) and then adjusted to pH 8~9 with 28% aqueous ammonia solution (7.6 g). The aqueous solution thus obtained was extracted with dichloromethane (100.0 g) and distilled under reduced pressure to obtain 8.5 g of the title compound as a white solid.

¹H NMR (500 MHz, CDCl₃) δ 1.44 (s, 9H), 1.45 (s, 9H), 2.45 (d, J=6.1 Hz, 2H), 2.77 (d, J=5.5 Hz, 2H), 3.87 (br s, 1H), 5.22 (br s, 1H).

EXAMPLE 8: Synthesis of N,N-dibenzyl-L-N(Boc)-aspartamide 4-tert-butyl ester

N-Boc-L-aspartic acid 4-t-butyl ester (29.0 g, 0.10 mol) was added to THF (200 ml). After cooling to temperature below -5℃, to the reaction solution was added isobutylchloroformate (13.0 ml, 0.10 mol) followed by addition of N-methyl morpholine (12.0 ml, 0.10 mol) dropwise, and the reaction mixture was stirred for over 30 minutes. To the reaction mixture was added dropwise dibenzylamine (21.1 ml, 0.11 mol), and the mixture was then stirred for over 3 hours and monitored for the reaction progress by TLC (EtOAc: Hexane=1:4). Upon completion of the reaction, the reaction solution was stirred with addition of ethyl acetate (300.0 mL) and 1 N hydrochloric acid to separate the layers, and distilled under reduced pressure to precipitate a solid. The solid was filtered and washed with ethyl acetate (100 ml), and then the washings were concentrated by distillation again under reduced pressure. The residue was then subjected to silica gel column to obtain the purified desired product (41.7 g, 0.89 mol).

¹H NMR (400 MHz, CDCl₃) δ: 7.32 (m, 5H), 7.20 (m, 5H), 5.39 (d, J=7.2 Hz, 1H), 5.30 (m, 1H), 4.87-4.77 (m, 2H), 4.48-4.39 (m, 2H), 2.72 (dd, J=15.8 Hz, J=8.0 Hz, 1H), 2.56 (dd, J=15.8 Hz, J=6.4 Hz, 1H), 1.43 (s, 9H), 1.37 (s, 9H).

Mass (ESI, m/z): 491 (M+Na), 469 (M+H), 413 (M-55).

EXAMPLE 9: Synthesis of N, N-diallyl-L-N(Boc)-aspartamide 4-tert-butyl ester

L-N(Boc)-aspartic acid 4-t-butyl ester (5.00 g, 17.3 mol) was added to THF (50 ml). After cooling to temperature below -5℃, to the reaction solution was added isobutylchloroformate (2.26 ml, 17.3 mol) followed by addition of N-methyl morpholine (1.90 ml, 17.3 mol) dropwise, and the reaction mixture was stirred for over 30 minutes. To the reaction mixture was added dropwise diallylamine (2.35 ml, 19.0 mol), and the mixture was then stirred for over 3 hours and monitored for the reaction progress by TLC (EtOAc: Hexane=1:4). Upon completion of the reaction, the reaction solution was stirred with addition of ethyl acetate (60 ml) and 1 N hydrochloric acid and, after separating the layers, concentrated by distillation under reduced pressure. The residue was then subjected to silica gel column to obtain the purified desired product (6.0 g, 16.3 mol).

¹H NMR (400 MHz, CDCl₃) δ: 5.78 (m, 2H), 5.30 (m, 1H), 5.23-5.11 (m, 1H), 5.30 (m, 1H), 4.93 (m, 1H), 4.11-3.84 (m, 4H), 2.68 (dd, J=15.8 Hz, J=8.0 Hz, 1H), 2.51 (dd, J=15.8 Hz, J=8.0 Hz, 1H), 1.44 (s, 9H), 1.42 (s, 9H).

Mass (ESI, m/z): 391 (M+Na), 369 (M+H), 313 (M-55).

EXAMPLE 10: Synthesis of N,N-dibenzyl-4-amino-3(S)-N(Boc)-aminobutanoic acid 4-tert-butyl ester

10.0 g of the compound obtained from the above Example 8, Ru₃(CO)₁₂ (136 mg, 1mol%), and diphenylsilane (19.7 ml, 106.7 mmol) were added to tetrahydrofuran (50 ml), and the reaction solution was stirred under reflux for over 40 hours. The reaction solution was extracted with ethyl acetate (200 ml) and concentrated by distillation under reduced pressure. The residue was then subjected to silica gel column to obtain the purified desired product (4.7 g, 10.5 mmol).

¹H NMR (400 MHz, CDCl₃) δ: 7.31-7.20 (m, 10H), 5.12 (bs, 1H), 3.90 (bs, 1H), 3.63 (d, J=12.0 Hz, 2H), 3.48 (d, J=12.0 Hz, 2H), 3.24 (m, 1H), 3.16 (bs, 1H), 2.42 (m, 2H), 1.81 (m, 1H), 1.59 (m, 9H), 1.46 (s, 9H), 1.06 (s, 9H).

Mass (ESI, m/z): 455 (M+H), 441 (M-13).

EXAMPLE 11: Synthesis of tert-butyl (3S)-4-amino-3-[(tert-butoxycarbonyl)amino]- 4-oxobutanoate

360.0 g of the starting material, N-Boc-Asp(O-t-Bu)OH, together with Boc₂O (353.0 g) and ammonium bicarbonate (NH₄HCO₃, 123.9 g) was added to dimethylformamide (1174.6 g), and pyridine (61.0 g) was added dropwise thereto at room temperature, and the reaction mixture was then stirred for about 3 hours. Upon completion of the reaction, water (1440 ml) and toluene (1800 ml) were added to the reaction solution and stirred for 30 minutes to separate the layers. The organic layer thus obtained was distilled under reduced pressure to remove t-butanol and toluene to obtain the title compound, which was directly used in the next reaction.

EXAMPLE 12: Synthesis of (S)-tert-butyl 3-(tert-butoxycarbonylamino)-3-cyanopropanoate

To the compound obtained from Example 11 was added dimethylformamide (1019.5 g) followed by addition of cyanuric chloride (112.0 g) dropwise for 1.5 hours at temperature below 25℃. The reaction solution was stirred for one hour at room temperature, and then 0.1 N aqueous sodium hydroxide solution (1850.0 g) and toluene (1860 ml) were added thereto to separate the layers. The organic layer thus obtained was washed once again with water (700 ml) and then distilled under reduced pressure to obtain 318.3 g of the title compound.

¹H NMR (500 MHz, CDCl₃) δ: 1.44 (s, 9H), 1.45 (s, 9H), 2.45 (d, J=6.1 Hz, 2H), 2.77 (d, J=5.5 Hz, 2H), 3.87 (br s, 1H), 5.22 (br s, 1H).

EXAMPLE 13: Synthesis of tert-butyl (3S)-4-amino-3-[(tert-butoxycarbonyl)amino]- butanoate

To 212.1 g of the compound obtained from the above Example 12 was added acetic acid (4000 ml) followed by addition of 20 wt% Pd(OH)₂ (1.1 g) at 40℃. The mixture was stirred for 8 hours while keeping the internal temperature below 45℃ and 3 atmospheric pressure of hydrogen. Upon completion of the reaction, the reaction solution was distilled under reduced pressure to remove acetic acid, diluted with toluene (640 L) and then filtered through a celite. To the filtrate was added 0.25 N aqueous hydrochloric acid solution (1060 ml) to separate the layers. The aqueous layer thus obtained was basified with aqueous ammonia solution (543.1 g) and then extracted with methyl t-butyl ether (MTBE, 1000 ml). The organic layer thus obtained was distilled under reduced pressure to obtain 185.0 g of the title compound.

EXAMPLE 14: Synthesis of 3-t-butoxycarbonylamino-4-(5,5-difluoro-2-oxo- piperidin-1-yl)-butyric acid t-butyl ester

Triethylamine (13.2 g) was added to 16.0 g of the compound obtained from the above Example 1 or 2-1 or 2-2, and 14.1 g of the compound obtained from the above Example 7 or 13, and the mixture was then stirred for 21 hours at 40℃. Then, dichloromethane (154.8 g) and acetic acid (18.3 g) were added, and the mixture was stirred for 5 hours at room temperature. To the resulting reaction solution was added 0.5 N aqueous hydrochloric acid solution (116.8 g) and then, the mixture was stirred for 30 minutes to separate the layers. The organic layer thus obtained was distilled under reduced pressure to obtain 23.6 g of the title compound.

¹H NMR (500 MHz, CDCl₃) δ: 1.42 (s, 9H), 1.46 (s, 9H), 2.27 (m, 2H), 2.40-2.64 (m, 4H), 3.20 (dd, J=4.3, 13.5 Hz, 1H), 3.56-3.70 (m, 2H), 3.76-3.91 (m, 2H), 4.16 (m, 1H), 5.20 (d, J=8.6 Hz, 1H).

EXAMPLE 15: Synthesis of 3-t-butoxycarbonylamino-4-(5,5-difluoro-2-oxo- piperidin-1-yl)-butyric acid

23.6 g of the compound obtained from the above Example 14 was added to dichloromethane (20.0 g) followed by addition of H₃PO₄ (30.0 g), and the mixture was stirred for 16 hours at room temperature. After confirming the detachment of all of t-butyl group and t-butyloxycarbonyl group, the reaction solution was adjusted to pH 7.0~8.0 with 10 N aqueous hydrogen peroxide, and Boc₂O (16.0 g) was added thereto. After completion of the addition, 10 N aqueous hydrogen peroxide was used to maintain the pH of the reaction solution at 8.0~9.0. After stirring for 3 hours, the resulting sodium phosphate was filtered off, and the filtrate was then adjusted to pH 2.0~3.0 with 3.0 N aqueous hydrochloric acid solution. The resulting solid was filtered and dried under nitrogen to obtain 14.5 g of the title compound.

¹H NMR (500 MHz, CDCl₃) δ: 1.32 (s, 9H), 2.20-2.43 (m, 6H), 3.26-3.31 (m, 2H), 3.61 (m, 1H), 3.81 (m, 1H), 4.02 (m, 1H), 6.73 (d, J=8.6 Hz, 1H), 12.16 (s, 1H).

For the title compound resulting from the above, its enantiomeric isomers―i.e. S-form and R-form―were measured by HPLC (high-performance liquid chromatography), and an excess of the enantiomeric isomers (S vs. R form) (enantiomeric excess; ee) was then calculated as being ee > 99%. On the other hand, in case of the Comparative Example prepared according to the prior method based on WO 06/104356, as described below, the excess (ee) of enantiomeric isomers (S vs. R form) was 80%. From this, it can be identified that the compound of formula (2) having an optically high purity could be obtained according to the method of the present invention.

COMPARATIVE EXAMPLE 1: Synthesis of 3-t-butoxycarbonylamino-4-(5,5- difluoro-2-oxo-piperidin-1-yl)-butyric acid t-butyl ester

COMPARATIVE EXAMPLE 1-1: Synthesis of methyl 5-amino-4,4-difluoro- pentanoate HCl

To 10.0 g of the compound obtained from Example 1 was added 40 ml of anhydrous ammonia solution (7 M solution in methanol), and the mixture was stirred for 3 hours. The reaction solution was distilled and 30 ml of hydrochloric acid solution saturated with methanol was added dropwise thereto. The reaction mixture was stirred at room temperature and then distilled to obtain 7.2 g of the title compound as a white solid.

¹H NMR (500 MHz, CD₃OD) δ: 2.35 (m, 2H), 2.59 (t, J=7.6 Hz, 2H), 3.49 (t, J=15.3 Hz, 2H), 3.68 (s, 3H).

COMPARATIVE EXAMPLE 1-2: Synthesis of 3-t-butoxycarbonylamino-4-(5,5- difluoro-2-oxo-piperidin-1-yl)-butyric acid t-butyl ester

To the solution of the compound (1.93 g), as obtained from the above Example 4, dissolved in dichloromethane (20.0 g) and H₂O (4.0 g) were added NaBr (0.8 g) and TEMPO (11 mg, 1 mol%). To this reaction solution was slowly added a solution of 5% NaOCl (11.5 g) and NaHCO₃ (1.7 g) dissolved in H₂O (12.0 g) dropwise for about 2 hours while maintaining the temperature below 5℃. Upon completion of dropwise addition, the reaction solution was stirred for 30 minutes to separate the layers. To the organic layer thus obtained was added the compound (1.6 g) obtained from the above Comparative Example 1-1. After stirring for 15 minutes at room temperature, NaBH(OAc)₃ (2.23 g) was added to the reaction solution. After stirring for about 19 hours, 10% aqueous NaHCO₃ solution (20.0 g) and 0.5 N aqueous hydrochloric acid solution (20.0 g) were added dropwise to the reaction solution to separate the layers. The organic layer thus obtained was dehydrated under anhydrous MgSO₄ to obtain 2.0 g (yield 73%) of the same title compound as Example 14, as a yellow solid. For the title compound resulting from the above, its enantiomeric isomers―i.e., S-form and R-form―were measured by HPLC (high-performance liquid chromatography), and an excess (ee) of the enantiomeric isomers (S vs. R form) was then calculated as being ee = 80%.

Footnotes

Further reading

External links

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ANTHONY MELVIN CRASTO

ALOGLIPTIN

Alogliptin is a potent, selective inhibitor of DPP-4 with IC50 of <10 nM, exhibits greater than 10,000-fold selectivity over DPP-8 and DPP-9.

Alogliptin (trade name Nesina in the US^[1] and Vipidia in Europe^[2]) is an orally administered anti-diabetic drug in the DPP-4 inhibitor class,^[3] developed by Syrrx, a company which was acquired by Takeda Pharmaceutical Company in 2005. Like other medications for the treatment of Type 2 diabetes, alogliptin does not decrease the risk of heart attack and stroke. Like other members of the gliptin class, it causes little or no weight gain, exhibits relatively little risk of causing hypoglycemia, and exhibits relatively modest glucose-lowering activity. Alogliptin and other gliptins are commonly used in combination with metformin in patients whose diabetes cannot adequately be controlled with metformin alone.^[4]

Clinical study

Alogliptin is a dipeptidyl peptidase-4 inhibitor (DPP-4i) that is designed to slow the inactivation of incretin hormones GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic peptide). ^[5]

A randomized clinical trial reporting in 2011 aimed to determine the efficacy and safety of alogliptin versus placebo and vogliboseamong newly diagnosed Type 2 diabetes patients in Japan. The main outcome indicated that alogliptin was statistically superior to both comparitors.^[6]

A randomized clinical trial reporting in 2012 aimed to demonstrate that alogliptin was “non-inferior” to a “very low fat/calorie traditional Japanese diet” among newly diagnosed Type 2 diabetes patients in Japan. The outcome indicated that both the drug and dietary treatments comparably impacted indicators of the diabetic condition, such as HbA1c levels and glycemic efficacy. The drug treatment had its impact without changing body mass index (BMI), but the dietary treatment was accompanied by a significant reduction in the BMI.^[7]

A randomized clinical trial reporting in 2011 aimed to demonstrate the efficacy of alogliptin as an add-on agent in combination withmetformin and pioglitazone versus simply increasing the dosage of pioglitazone in combination with metformin; in other words, this was a study to look at a three-agent therapy versus a two-agent therapy. The outcome of this study suggested that the addition of alogliptin to metformin and pioglitazone provided superior impact on diabetes biomarkers (e.g. HbA1c) than increasing the dose of pioglitazone in a two agent therapy with metformin.^[8]

Reported adverse events

Adverse events appear to be restricted to mild hypoglycemia based on clinical studies.^[6][7][8]

Alogliptin is not associated with increased weight, increased risk of cardiovasular events, or heart failure.^[9][10]

Market access

In December 2007, Takeda submitted a New Drug Application (NDA) for alogliptin to the United States Food and Drug Adminiistration (USFDA),^[11] after positive results from Phase III clinical trials.^[1] In September of 2008, the company also filed for approval in Japan,^[12] winning approval in April 2010.^[11] The company also filed a Marketing Authorization Application (MAA) elsewhere outside the United States, which was withdrawn in June 2009 needing more data.^[12] The first USFDA NDA failed to gain approval and was followed by a pair of NDAs (one for alogliptin and a second for a combination of alogliptin and pioglitazone) in July 2011.^[11] In 2012, Takeda received a negative response from the USFDA on both of these NDAs, citing a need for additional data.^[11]

In 2013 the FDA approved the drug in three formulations: As a stand-alone with the brand-name Nesina. Combined with metforminusing the name Kazano, and when combined with pioglitazone as Oseni.

Diabetes affects millions of people worldwide and is considered one of the main threats to human health in the 21^st century. In 2006, the World Health Organization (WHO) estimated that over 180 million people worldwide had diabetes, and the number is projected to double by 2030. Over time, uncontrolled diabetes can damage body systems, including the heart, blood vessels, eyes, kidneys and nerves. According to the WHO, approximately 1.1 million people died from diabetes in 2005, and it is estimated that diabetes-related deaths will increase by more than 50% in the next decade. Globally, the socioeconomic burden of diabetes is substantial.

There are two main types of diabetes, designated type 1 and type 2, with type 2 diabetes accounting for over 90% of all diabetes cases globally. Type 1 diabetes is characterized by insulin deficiency, primarily caused by autoimmune-mediated destruction of pancreatic islet β-cells, and type 2 diabetes is characterized by abnormal insulin secretion and concomitant insulin resistance. To prevent the development of ketoacidosis, people with type 1 diabetes must take exogenous insulin for survival. Although those with type 2 diabetes are not dependent on exogenous insulin as much as subjects with type 1 diabetes, they may require exogenous insulin to control blood glucose levels.

As diabetes has become a global health concern, research interest in the condition has rapidly increased. In addition to studies on prevention, many studies with the aim of developing new interventions for the treatment of diabetes, especially type 2 diabetes, have been conducted. Currently available medications for the treatment and management of type 2 diabetes include metformin, sulfonylureas, thiazolidinediones and insulin. However, these therapies are commonly associated with secondary failure and may cause hypoglycemia. Insulin resistance and progressively worsening hyperglycemia caused by reduced β-cell function are major challenges in managing type 2 diabetes. Evidence suggests that patients with insulin resistance do not develop hyperglycemia until their β-cells are unable to produce enough insulin. New agents that can enhance insulin secretion from islet β-cells in a sustained glucose-dependent manner could therefore hold promise for the treatment of type 2 diabetes.

One promising approach is based on inhibition of the serine protease dipeptidyl- peptidase IV (DPP IV), a postproline dipeptidyl aminopeptidase that belongs to the S9b peptidase family of proteolytic enzymes. It is known that DPP IV plays a key role in maintaining glucose homeostasis by controlling the incretin activity of glucagon-like peptide 1 (GLP-I) and glucose-dependent insulinotropic polypeptide (GIP, also known as gastric inhibitory polypeptide). Inhibition of DPP IV is therefore recognized as a novel therapeutic approach for the treatment of type 2 diabetes.

Recently, a series of DPP IV inhibitors were developed. Among these highly potent compounds, alogliptin benzoate (SYR-322) and its analogs demonstrated encouraging antidiabetic efficacy (EP 1586571 (WO 2005/095381); WO 2008/067465; WO 2007/035379, and US 2004/097510).

Alogliptin benzoate can be prepared as described in EP 1586571 (WO 2005/095381) according to the process set forth in Scheme 1 :

Scheme 1

In accordance with this process, 6-Chlorouracil (1) is alkylated with 2- (bromomethyl)benzonitrile in the presence of NaH and LiBr in a mixture of DMF- DMSO to produce the TV-benzyluracil derivative (2) in 54% yield. Compound (2) is further alkylated with iodomethane and NaH in DMF/THF to give the 1 ,3 disubstituted uracil (3) in 72% yield. Subsequent displacement of chlorouracil (IV) with 3(R)- aminopiperidine dihydrochloride in the presence of either NaHCO₃ in hot methanol or K₂CO₃ in aqueous isopropanol provides alogliptin (4), which is isolated as the corresponding benzoate salt by treatment with benzoic acid in ethanol. The overall yield of this three-stage process is -20-25%. One of the disadvantages of above described process is the difficulty to separate and purify mixtures of solvents with high boiling point (for example, DMF/DMSO) for recycling. Another disadvantage is the usage of hazardous materials such as sodium hydride, which requires anhydrous solvents as a reaction media.

Intermediate 2-((6-chloro-3-methyl-2,4-dioxo-3 ,4-dihydropyrimidin- 1 (2H)-yl)methyl) benzonitrile (3) is alternatively obtained by alkylation of 6-chloro-3 methyluracil with 2-(bromomethyl)benzonitrile by means of diisopropylethylamine in hot NMP (WO 2007/035629). Although this process is more technological than the previously described process (EP 1586571), the overall yield is still moderate (50-55%). The problem of mixed solvents (toluene, NMP, diisopropylethylamine) separation persists for this process as well.

………….

http://www.google.com/patents/EP2410855A1?cl=en

EXAMPLE 1

Preparation of (R)-2-((6-(3 -aminopiperidin-l-yl)-3 -methyl-2,4-dioxo-3 ,4- dihydropyrimidin-1 (2H)-yl) methyl)benzonitrile (alogliptin) via 6-chloro-l-(2- isocyanobenzyl)-3-methylpyrimidine-2,4(lH,3H)-dione (Scheme 3):

Scheme 3

Preparation of l-(2-isocyanobenzyl)-3-methylurea

2-cyanobenzylamine hydrochloride (90 g) and Dichloromethane (800 ml) were taken into a round bottomed (RB) flask. Methyl isocyanate (45.6 g) was added at 5°C. Triethylamine (81 g) in Dichloromethane (300 ml) was added at the same temperature and stirred at room temperature for 16h. Water (1 L) was added and stirred for 30 min. The obtained solid was collected by filtration and dried in oven at 50°C for 12h. The yield is 85% and the purity 99.8%.

Preparation of l-(2-isocyanobenzyl)-3-methyIpyrimidine-2,4,6(lH,3H,5H)-trione

a). To a stirred solution of 0.11 mol of sodium ethanolate in 80 ml of ethanol abs. was added 0.1 mol of l-(2-isocyanobenzyl)-3-methylurea and 0.1 mol diethyl malonate. The mixture was refluxed for 3-5 h. The cooled residue was acidified with 0.1 M hydrochloric acid (60 ml). The solid which separated was filtered off and recrystallized from ethanol or any suitable solvent. The yield is 78-85% and purity >95%.

b). In an alternate embodiment, l-(2-isocyanobenzyl)-3-methylurea (30 g), acetic acid (105 ml) and malonic acid (18 g) were mixed and heated to 60°C. Acetic anhydride (60 ml) was added at 60°C and heating was continued for two hours at 80°C. The reaction mixture was poured over ice water (300 ml) and the obtained solid was filtered, washed with water (1×500 ml) and methyl-tert-butylether (100 ml). The yield is 60% with 93.4% purity.

The compound thus prepared can be used for the next step without purification or purified by crystallization or column chromatography.

Preparation of 6-chloro-l-(2-isocyanobenzyl)-3-methylpyriinidine-2,4(lH,3H)- dione

a). l-(2-isocyanobenzyl)-3-methylpyrimidine-2,4,6(lH,3H,5H)-trione (30 g) was mixed with phosphorus oxychloride (300 ml) and cooled to 0°C. Water (9 ml) was added slowly, stirred for 10 min. and heated to reflux at 110°C for 5h. Progress of the reaction was monitored by TLC (50% Ethyl acetate/Hexane). On completion of the reaction, phosphorus oxychloride was distilled off. The crude compound was dissolved in dichloromethane (500 ml) and poured into ice water (500 ml) by small portions. The layers were separated and the aqueous layer was extracted with dichloromethane (200 ml). The combined organic extracts were washed with water and brine, dried over sodium sulphate and concentrated under reduced pressure. The mixture of two isomers (4-chloro and 6-chloro derivatives = 1:1) was isolated and separated by column chromatography using neutral alumina and eluent – 25-50% of ethylacetate and hexane). The off-white solid was obtained, yield – 37%, purity – 99.8%. ¹H NMR corresponds to literature data (J. Med. Chem. 2007, 50, 2297-2300).

b). In an alternate embodiment, a solution of l-(2-isocyanobenzyl)-3-methylpyrimidine- 2,4,6(1 H,3H,5H)-trione (18 mmol), phosphorus oxychloride (85 ml), benzyltriethylammonium chloride (16.5 g, 72 mmol) and phosphorus pentachloride (3.8 g, 18 mol) in acetonitrile (80 ml) was refluxed for 4-5 h with stirring. After evaporation under reduced pressure, the resulting oily residue was mixed with methylene chloride (or chloroform) and the mixture was poured into water and ice (50 ml). The layers were separated and the aqueous layer was extracted with dichloromethane (200 ml). The combined organic extracts were washed with water and brine, dried over sodium sulphate and concentrated under reduced pressure. Crude product was crystallized from THF-hexanes to give desired compound in 70.5% yield.

c). In an alternate embodiment, a solution of l-(2-isocyanobenzyl)-3-methylpyrimidine- 2,4,6(1 H,3H,5H)-trione (13.1 mmol) in POCl₃ (30 ml) was refluxed for 1-3 h. The solvent was concentrated and then partitioned with CH₂Cl₂ (100 ml) and water (100 ml). The organic layer was washed with brine, dried over Na₂SO₄, and concentrated to give 6-chloro compound as a solid (-95%). Compound can be also precipitated from concentrated methylene chloride solution by hexanes and used as a crude for the next step or purified by reslurring in isopropanol, filtered off, washed with isopropanol, and dried under vacuum at 55-60° C.

Preparation of (R)-tert-butyl l-(3-(2-isocyanobenzyI)-l-methyl-2,6-dioxo-l,2,3,6- tetrahydropyrimidin-4-yl)piperidin-3-yl carbamate

a). 6-chloro- l-(2-isocyanobenzyl)-3-methylpyrimidine-2,4(lH,3H)-dione (13 g), Dimethylformamide (130 ml), Potassium carbonate (13 g) and tert-butyl (R)-piperidin- 3-ylcarbamate (10.4 g) were heated to 80°C for 7 hrs. The mixture was then allowed to come to room temperature and poured over ice water (500 ml). The obtained solid was filtered and washed with cold water (500 ml). The solid thus obtained was taken in Methyl-tert-butylether (50 ml) stirred for 10 min. filtered and washed with Hexane (50 ml), to give the N-tert-butyloxycarbonyl protected compound in -75% yield. b). In an alternate embodiment, a flask charged with a stir bar, 6-chloro-l-(2- isocyanobenzyl)-3-methylpyrimidine-2,4(lH,3H)-dione (4.10 mmol), (Λ)-3- terrtnityloxycarbonylaminopiperidine (4.64 mmol), K₂CO3 (1.15 g, 8.32 mmol) and DMF (12 mL) was stirred at 75 °C for 6 h. Then, water was added and the mixture was extracted with methylene chloride. The organic layer was washed with brine, dried over Na₂SO₄, and concentrated to give the N-ter/butyloxycarbonyl protected compound in -93-96% yield.

Preparation of (R)-2-((6-(3-aminopiperidin-l-yl)-3-methyl-2,4-dioxo-3,4- dihydropyrimidin-1 (2H)-yl) methyl)benzonitrile salts

a). Preparation of (R)-2-((6-(3-aminopiperidin-l-yl)-3-methyl-2,4-dioxo-3,4- dihydropyrimidin-1 (2H)-yl) methyl)benzonitrile hydrochloride

The crude (R)-tert-butyl l-(3-(2-isocyanobenzyl)-l-methyl-2,6-dioxo-l,2,3,6- tetrahydropyrimidin-4-yl)piperidin-3-yl carbamate from previous procedure was dissolved in THF and acidified with 6M hydrochloric acid while maintaining the temperature below 15° C. The resultant slurry was cooled to 0-5° C, stirred at this temperature for 3-5 h and then filtered. The filter cake was washed twice with isopropanol and dried in vacuum at 45-5O⁰C to provide hydrochloride as a white crystalline solid.

b). Preparation of (R)-2-((6-(3-aminopiperidin-l-yl)-3-methyl-2,4-dioxo-3,4- dihydropyrimidin-1 (2H)-yl) methyl)benzonitrile trifluoroacetate

TFA (ImL) was added into the methylene chloride solution of (R)-tert-butyl l-(3-(2- isocyanobenzyl)- 1 -methyl-2,6-dioxo- 1 ,2,3,6-tetrahydropyrimidin-4-yl)piperidin-3-yl carbamate from the above-mentioned procedure. The solution was stirred at room temperature for 1 h and then the mixture was concentrated in vacuo. The residue was dissolved in a small amount of MeOH or isopropanol and the desired salt was precipitated by addition of diisopropyl ether. The solids were filtered off, washed with diisopropyl ether and dried in vacuum at 45-5O⁰C to provide trifluoroacetate as an off- white powder. c). Preparation of (R)-2-((6-(3-aminopiperidin-l-yl)-3-methyl-2,4-dioxo-3,4- dihydropyrimidin-1 (2H)-yl) methyl)benzonitrile benzoate (Alogliptin)

The crude (R)-tert-butyl l-(3-(2-isocyanobenzyl)-l-methyl-2,6-dioxo-l,2,3,6- tetrahydropyrimidin-4-yl)piperidin-3-yl carbamate was dissolved in ethanol. A solution of benzoic acid in ethanol was added and the mixture was slowly heated to 65-70°C. The solution was stirred at this temperature for Ih and was then crystallized by cooling to 0-5° C and stirring for 12 hrs. The solution was filtered, washed with alcohol. The wet cake was then conditioned under nitrogen for 2 hours. The cake was dried for 8 hrs at 40-50° C to provide the benzoic acid salt of alogliptin as a white crystalline solid.

EXAMPLE 2:

Preparation of (R)-2-((6-(3-aminopiperidin-l-yl)-3-methyl-2,4-dioxo-3,4- dihydropyrimidin-1 (2H)-yl) methyl)benzonitrile (alogliptin) via 6-amino-l-(2- isocyanobenzyl)-3-methylpyrimidine-2,4(lH,3H)-dione (Scheme 4)

Scheme 4 Preparation of 6-amino-l-(2-isocyanobenzyl)-3-methylpyrimidine-2,4(lH,3H)- dione

a). l-(2-isocyanobenzyl)-3-methylurea (0.2 mol) and cyanoacetic acid (0.22 mol) were dissolved in acetic anhydride (400 ml), and the mixture was heated at 80°C for 2 hours. Acetic anhydride was distilled off under reduced pressure and water (200 ml) was added. The mixture was cooled to 0-5 ⁰C and 2N NaOH solution (220 ml) was added and stirring was continued for 2 hours. The obtained solids were filtered off, washed with cold methanol and dried under vacuum. The yield of 6-amino-l-(2- isocyanobenzyl)-3-methylpyrimidine-2,4(lH,3H)-dione was 72 %.

b). Under nitrogen atmosphere, l-(2-isocyanobenzyl)-3-methylurea (98.4 g) and cyanoacetic acid (80.0 g) was added to N,N-dimethylformamide (836 ml). The mixture was stirred at room temperature and methanesulfonyl chloride (72.8 ml) was added dropwise with stirring at this temperature. The mixture was stirred at room temperature for 4 hrs, cooled with water, and water-isopropanol [2:1 (volume ratio), 1670 ml] was added drop wise. The mixture was stirred under water-cooling for 1 hr, and the precipitated crystals were collected by filtration and dried to give 3-(2-cyano-acetyl)-3- methyl-l-(2-isocyanobenzyl)-urea with 68% yield.

To 3-(2-cyano-acetyl)-3-methyl-l-(2-isocyanobenzyl)-urea (120 g) were added water (962 ml) and 2N aqueous sodium hydroxide solution (24.9 ml), and the mixture was stirred with heating at 80° C for 1 hr. After allowing to cool to room temperature, the crystals were collected by filtration and dried to give 6-amino-l-(2-isocyanobenzyl)-3- methylpyrimidine-2,4(lH,3H)-dione in 76% yield.

c). 6-amino-l-(2-isocyanobenzyl)-3-methylpyrimidine-2,4(lH,3H)-dione (0.1 mol) was mixed with (R)-piperidin-3-yl-carbamic acid tert.-butyl ester hydrochloride (0.1 mol) of the appropriate amine hydrochloride and (R)-piperidin-3-yl-carbamic acid tert.-butyl ester (0.1 mol). The mixture was heated at 100°C and bubbling continued for 3 hr. Water was added to the cooled mixture and the mixture was extracted with methylene chloride. The organic layer was washed with brine, dried over Na₂SO₄, and concentrated to give N-tert-butyloxycarbonyl protected compound in ~93-96% yield.

d). Benzoate salt of alogliptin was prepared as described above. While certain embodiments of the invention have been illustrated and described, it will be clear that the invention is not limited to the embodiments described herein. Numerous modifications, changes, variations, substitutions and equivalents will be apparent to those skilled in the art without departing from the spirit and scope of the present invention as described by the claims, which follow.

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Patent EP2410855A1

http://www.google.com/patents/EP2410855A1?cl=en

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NMR

SOURCE  APEXBT

References

Alogliptin

Systematic (IUPAC) name
2-({6-[(3R)-3-aminopiperidin-1-yl]-3-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl}methyl)benzonitrile
Clinical data
Trade names	Nesina, Vipidia Kazano, Vipidomet (withmetformin) Oseni, Incresync (withpioglitazone)
Pregnancy category	US: B (No risk in non-human studies)
Legal status	℞ (Prescription only)
Routes of administration	Oral
Pharmacokinetic data
Bioavailability	100%
Protein binding	20%
Metabolism	Limited, hepatic (CYP2D6– and3A4-mediated)
Biological half-life	12–21 hours
Excretion	Renal (major) and fecal (minor)
Identifiers
CAS Registry Number	850649-62-6  BENZOATE850649-61-5 FREE BASE
ATC code	A10BH04
PubChem	CID: 11450633
IUPHAR/BPS	6319
ChemSpider	9625485
UNII	JHC049LO86
KEGG	D06553
ChEBI	CHEBI:72323
ChEMBL	CHEMBL376359
Synonyms	SYR-322
Chemical data
Formula	C18H21N5O2
Molecular mass	339.39 g/mol

Alogliptin benzoate

Solubility:Soluble in MeOH; Insoluble in ACN

850649-62-6  ^CAS

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