Prexasertib , прексасертиб , بريكساسيرتيب , 普瑞色替 ,

Prexasertib

Captisol^® enabled prexasertib; CHK1 Inhibitor II; LY 2606368; LY2606368 MsOH H2O

5-(5-(2-(3-aminopropoxy)-6-methoxyphenyl)-1H-pyrazol-3-ylamino)pyrazine-2-carbonitrile

2-Pyrazinecarbonitrile, 5-[[5-[2-(3-aminopropoxy)-6-methoxyphenyl]-1H-pyrazol-3-yl]amino]-

Name	Prexasertib
Lab Codes	LY-2606368
Chemical Name	5-({5-[2-(3-aminopropoxy)-6-methoxyphenyl]-1H-pyrazol-3-yl}amino)pyrazine-2-carbonitrile
Chemical Structure
Molecular Formula	C18H19N7O2
UNII	UNII:820NH671E6
Cas Registry Number	1234015-52-1
OTHER NAMES	прексасертиб [Russian] [INN] بريكساسيرتيب [Arabic] [INN] 普瑞色替 [Chinese] [INN]
Originator	Array BioPharma
Developer	Eli Lilly, National Cancer Institute
Mechanism Of Action	Checkpoint kinase inhibitors, Chk-1 inhibitors
Who Atc Codes	L01X-E (Protein kinase inhibitors)
Ephmra Codes	L1H (Protein Kinase Inhibitor Antineoplastics)
Indication	Breast cancer, Ovarian cancer, Solid tumor, Head and neck cancer, Leukemia, Neoplasm Metastasis, Colorectal Neoplasms, Squamous Cell Carcinoma

2100300-72-7 CAS

Prexasertib mesylate hydrate
CAS#: 1234015-57-6 (mesylate hydrate)
Chemical Formula: C19H25N7O6S
Molecular Weight: 479.512, CODE LY-2940930
LY-2606368 (free base)

Prexasertib mesylate ANHYDROUS
CAS#: 1234015-55-4 (mesylate)
Chemical Formula: C19H23N7O5S
Molecular Weight: 461.497

Prexasertib dihydrochloride
1234015-54-3. MW: 438.3169

LY2606368 is a small-molecule Chk-1 inhibitors invented by Array and being developed by Eli Lilly and Company. Lilly is responsible for all clinical development and commercialization activities. Chk-1 is a protein kinase that regulates the tumor cell’s response to DNA damage often caused by treatment with chemotherapy. In response to DNA damage, Chk-1 blocks cell cycle progression in order to allow for repair of damaged DNA, thereby limiting the efficacy of chemotherapeutic agents. Inhibiting Chk-1 in combination with chemotherapy can enhance tumor cell death by preventing these cells from recovering from DNA damage.

Originator Array BioPharma; Eli Lilly

Developer Eli Lilly; National Cancer Institute (USA)

Class Antineoplastics; Nitriles; Pyrazines; Pyrazoles; Small molecules

Mechanism of Action Checkpoint kinase 1 inhibitors; Checkpoint kinase 2 inhibitors

Highest Development Phases

• Phase II Breast cancer; Ovarian cancer; Small cell lung cancer; Solid tumours
• Phase I Acute myeloid leukaemia; Colorectal cancer; Head and neck cancer; Myelodysplastic syndromes; Non-small cell lung cancer

Most Recent Events

• 10 Apr 2017 Eli Lilly completes a phase I trial for Solid tumours (Late-stage disease, Second-line therapy or greater) in Japan (NCT02514603)
• 10 Mar 2017 Phase-I clinical trials in Solid tumours (Combination therapy, Metastatic disease, Inoperable/Unresectable) in USA (IV) (NCT03057145)
• 22 Feb 2017 Khanh Do and AstraZeneca plan a phase H trial for Solid tumour (Combination therapy, Metastatic disease, Inoperable/Unresectable) in USA (NCT03057145)

Prexasertib (LY2606368) is a small molecule checkpoint kinase inhibitor, mainly active against CHEK1, with minor activity against CHEK2. This causes induction of DNA double-strand breaks resulting in apoptosis. It is in development by Eli Lilly. ^[1]

A phase II clinical trial for the treatment of small cell lung cancer is expected to be complete in December 2017.^[2]

an aminopyrazole compound, or a pharmaceutically acceptable salt thereof or a solvate of the salt, that inhibits Chkl and is useful for treating cancers characterized by defects in deoxyribonucleic acid (DNA) replication, chromosome segregation, or cell division.

Chkl is a protein kinase that lies downstream from Atm and/or Atr in the DNA damage checkpoint signal transduction pathway. In mammalian cells, Chkl is phosphorylated in response to agents that cause DNA damage including ionizing radiation (IR), ultraviolet (UV) light, and hydroxyurea. This phosphorylation which activates Chkl in mammalian cells is dependent on Atr. Chkl plays a role in the Atr dependent DNA damage checkpoint leading to arrest in S phase and at G2M. Chkl phosphorylates and inactivates Cdc25A, the dual-specificity phosphatase that normally dephosphorylates cyclin E/Cdk2, halting progression through S-phase. Chkl also phosphorylates and inactivates Cdc25C, the dual specificity phosphatase that dephosphorylates cyclin B/Cdc2 (also known as Cdkl) arresting cell cycle progression at the boundary of G2 and mitosis (Fernery et al, Science, 277: 1495-1, 1997). In both cases, regulation of Cdk activity induces a cell cycle arrest to prevent cells from entering mitosis in the presence of DNA damage or unreplicated DNA. Various inhibitors of Chkl have been reported. See for example, WO 05/066163,

WO 04/063198, WO 03/093297 and WO 02/070494. In addition, a series of aminopyrazole Chkl inhibitors is disclosed in WO 05/009435.

However, there is still a need for Chkl inhibitors that are potent inhibitors of the cell cycle checkpoints that can act effectively as potentiators of DNA damaging agents. The present invention provides a novel aminopyrazole compound, or a pharmaceutically acceptable salt thereof or solvate of the salt, that is a potent inhibitor of Chkl . The compound, or a pharmaceutically acceptable salt thereof or a solvate of the salt, potently abrogates a Chkl mediated cell cycle arrest induced by treatment with DNA damaging agents in tissue culture and in vivo. Furthermore, the compound, or a pharmaceutically acceptable salt thereof or a solvate of the salt, of the present invention also provides inhibition of Chk2, which may be beneficial for the treatment of cancer. Additionally, the lack of inhibition of certain other protein kinases, such as CDKl, may provide a -2- therapeutic benefit by minimizing undesired effects. Furthermore, the compound, or a pharmaceutically acceptable salt thereof or a solvate of the salt, of the present invention inhibits cell proliferation of cancer cells by a mechanism dependent on Chkl inhibition.

WO 2010077758

Preparation 8

tert-Butyl 3-(2-(3-(5-cyanopyrazin-2-ylamino)-lH-pyrazol-5-yl)-3- methoxyphenoxy)propylcarbamate

A solution of tert-butyl 3-(2-(3-(5-bromopyrazin-2-ylamino)-lH-pyrazol-5-yl)-3- methoxyphenoxy)propylcarbamate (0.378 g, 0.730 mmol) and zinc cyanide (0.10 g, 0.870 mmol) in DMF (10 mL) is degassed with a stream of nitrogen for one hour and then -25- heated to 80 ⁰C. To the reaction is added Pd(Ph₃P)₄ (0.080 g, 0.070 mmol), and the mixture is heated overnight. The reaction is cooled to room temperature and concentrated under reduced pressure. The residue is purified by silica gel chromatography (CH₂Cl₂/Me0H) to give 0.251 g (73%) of the title compound.

Preparation 12 tert-Butyl 3-(2-(3-(5-cyanopyrazin-2-ylamino)-lH-pyrazol-5-yl)-3- methoxyphenoxy)propylcarbamate

A 5 L flange-neck round-bottom flask equipped with an air stirrer rod and paddle, thermometer, pressure-equalizing dropping funnel, and nitrogen bubbler is charged with 5-(5-(2-hydroxy-6-methoxy-phenyl)-lH-pyrazol-3-ylamino)-pyrazine-2-carbonitrile (47.0 g, 152 mmol) and anhydrous THF (1.2 L). The stirred suspension, under nitrogen, is cooled to 0 ⁰C. A separate 2 L 3 -necked round-bottom flask equipped with a large -28- magnetic stirring bar, thermometer, and nitrogen bubbler is charged with triphenylphosphine (44.0 g; 168 mmol) and anhydrous THF (600 mL). The stirred solution, under nitrogen, is cooled to 0 ⁰C and diisopropylazodicarboxylate (34.2 g; 169 mmol) is added and a milky solution is formed. After 3-4 min, a solution of7-butyl-N-(3- hydroxypropyl)-carbamate (30.3 g, 173 mmol) in anhydrous THF (100 mL) is added and the mixture is stirred for 3-4 min. This mixture is then added over 5 min to the stirred suspension of starting material at 0 ⁰C. The reaction mixture quickly becomes a dark solution and is allowed to slowly warm up to room temperature. After 6.5 h, more reagents are prepared as above using PPh₃ (8 g), DIAD (6.2 g) and carbamate (5.4 g) in anhydrous THF (150 mL). The mixture is added to the reaction mixture, cooled to -5 ⁰C and left to warm up to room temperature overnight. The solvent is removed in vacuo. The resulting viscous solution is loaded onto a pad of silica and product is eluted with ethyl acetate. The concentrated fractions are separately triturated with methanol and resulting solids are collected by filtration. The combined solids are triturated again with methanol (400 mL) and then isolated by filtration and dried in vacuo at 50 ⁰C overnight to give 31.3 g of desired product. LC-ES/MS m/z 466.2 [M+ 1]⁺.

Example 2

5 -(5 -(2-(3 -Aminopropoxy)-6-methoxyphenyl)- 1 H-pyrazol-3 -ylamino)pyrazine-2- carbonitrile dihydrogen chloride salt

A 5 L flange-neck, round-bottom flask equipped with an air stirrer rod and paddle, thermometer, and air condenser with bubbler attached, is charged with tert-bvXyl 3-(2-(3- (5-cyanopyrazin-2-ylamino)-lH-pyrazol-5-yl)-3-methoxyphenoxy)propylcarbamate (30.9 g, 66.3 mmol) and ethyl acetate (3 L). The mechanically stirred yellow suspension is cooled to just below 10 ⁰C. Then hydrogen chloride from a lecture bottle is bubbled in -29- vigorously through a gas inlet tube for 15 min with the ice-bath still in place. After 5 h the mixture is noticeably thickened in appearance. The solid is collected by filtration, washed with ethyl acetate, and then dried in vacuo at 60 ⁰C overnight to give 30.0 g. ¹H NMR (400 MHz, DMSO-d6) δ 2.05 (m, 2H), 2.96 (m, 2H), 3.81 (s, 3H), 4.12 (t, J = 5.8 Hz, 2H), 6.08 (br s, 3H), 6.777 (d, J = 8.2 Hz, IH), 6.782 (d, J = 8.2 Hz, IH), 6.88 (br s, IH), 7.34 (t, J = 8.2 Hz, IH), 8.09 (br s, IH), 8.55 (br s, IH), 8.71 (s, IH), 10.83 (s, IH), 12.43 (br s, IH). LC-ES/MS m/z 366.2 [M+lf.

Example 3 5 -(5 -(2-(3 -Aminopropoxy)-6-methoxyphenyl)- 1 H-pyrazol-3 -ylamino)pyrazine-2- carbonitrile

5-(5-(2-(3-Aminopropoxy)-6-methoxyphenyl)-lH-pyrazol-3-ylamino)pyrazine-2- carbonitrile dihydrogen chloride salt (3.0 g, 6.84 mmol) is suspended in 200 mL of CH₂Cl₂. 1 N NaOH is added (200 mL, 200 mmol). The mixture is magnetically stirred under nitrogen at room temperature for 5 h. The solid is collected by filtration and washed thoroughly with water. The filter cake is dried in vacuo at 50 ⁰C overnight to give 2.26 g (90%) of the free base as a yellow solid. ¹H NMR (400 MHz, DMSO-d6) δ 1.81 (m, 2H), 2.73 (t, J = 6.2 Hz, 2H), 3.82 (s, 3H), 4.09 (t, J = 6.2 Hz, 2H), 6.76 (t, J = 8.2 Hz, 2H), 6.93 (br s, IH), 7.31 (t, J = 8.2 Hz, IH), 8.52 (br s, IH), 8.67 (s, IH). LC- MS /ES m/z 366.2 [M+ 1]⁺.

Example 4

5 -(5 -(2-(3 -Aminopropoxy)-6-methoxyphenyl)- 1 H-pyrazol-3 -ylamino)pyrazine-2- carbonitrile methanesulfonic acid salt -30-

5-(5-(2-(3-aminopropoxy)-6-methoxyphenyl)-lH-pyrazol-3-ylamino)pyrazine-2- carbonitrile (1.0 g, 2.74 mmol) is suspended in MeOH (100 mL). A I M solution of methanesulfonic acid in MeOH (2.74 mL, 2.74 mmol) is added to the mixture dropwise with stirring. The solid nearly completely dissolves and is sonicated and stirred for 15 min, filtered, and concentrated to 50 mL. The solution is cooled overnight at -15 ⁰C and the solid that forms is collected by filtration. The solid is dried in a vacuum oven overnight to give 0.938 g (74%) of a yellow solid. ¹H NMR (400 MHz, DMSO-d6) δ 1.97 (m, 2H), 2.28 (s, 3H), 2.95 (m, 2H), 3.79 (s, 3H), 4.09 (t, J = 5.9 Hz, 2H), 6.753 (d, J = 8.4 Hz, IH), 6.766 (d, J = 8.4 Hz, IH), 6.85 (br s, IH), 7.33 (t, J = 8.4 Hz, IH), 7.67 (br s, 3H), 8.49 (br s, IH), 8.64 (s, IH), 10.70 (s, IH), 12.31 (s, IH). LC-ES/MS m/z 366.2 [M+l]⁺.

Preparation 18 tert-Butyl 3-(2-(3-(5-cyanopyrazin-2-ylamino)-lH-pyrazol-5-yl)-3- methoxyphenoxy)propylcarbamate

5-(5-(2-Hydroxy-6-methoxyphenyl)-lH-pyrazol-3-ylamino)pyrazine-2- carbonitrile (618 g, 1.62 mol) is slurried in tetrahydrofuran (6.18 L, 10 volumes) and chilled to -5 to 0 ⁰C with an acetone/ice bath. Triethylamine (330 g, 3.25 mol) is added through an addition funnel over 30 – 40 min at -5 to 5 ⁰C. The resulting slurry is stirred at -5 to 5 ⁰C for 60 – 90 min. The insoluble triethylamine hydrochloride is filtered and the solution of the phenol ((5-(2-hydroxy-6-methoxyphenyl)-lH-pyrazol-3- ylamino)pyrazine-2-carbonitrile) collected in an appropriate reaction vessel. The cake is rinsed with THF (1.24 L). The THF solution of the phenol is held at 15 to 20 ⁰C until needed.

Triphenylphosphine (1074 g, 4.05 mol) is dissolved at room temperature in THF (4.33 L). The clear colorless solution is cooled with an acetone/ice bath to -5 to 5 ⁰C. Diisopropylazodicarboxylate (795 g, 3.89 mol) is added dropwise through an addition funnel over 40 – 60 min, keeping the temperature below 10 ⁰C. The resulting thick white slurry is cooled back to -5 to 0 ⁰C. tert-Butyl 3-hydroxypropylcarbamate (717g, 4.05 moles) is dissolved in a minimum of THF (800 mL). The tert-butyl 3- hydroxypropylcarbamate/THF solution is added, through an addition funnel, over 20 – 30 -35- min at -5 to 5 ⁰C to the reagent slurry. The prepared reagent is stirred in the ice bath at -5 to 0 ⁰C until ready for use.

The prepared reagent slurry (20%) is added to the substrate solution at 15 to 20 ⁰C. The remaining reagent is returned to the ice bath. The substrate solution is stirred at ambient for 30 min, then sampled for HPLC. A second approximately 20% portion of the reagent is added to the substrate, stirred at ambient and sampled as before. Addition of the reagent is continued with monitoring for reaction completion by HPLC. The completed reaction is concentrated and triturated with warm methanol (4.33 L, 50 – 60 ⁰C) followed by cooling in an ice bath. The resulting yellow precipitate is filtered, rinsed with cold MeOH (2 L), and dried to constant weight to provide 544 g (72%) of the title compound, mp 214 – 216 ⁰C; ES/MS m/z 466.2 [M+l]⁺.

Example 5

2-Pyrazinecarbonitrile, 5-[[5-[-[2-(3-aminopropyl)-6-methoxyphenyl]-lH-pyrazol-3- yl]amino] monomesylate monohydrate (Chemical Abstracts nomenclature)

tert-Butyl 3-(2-(3-(5-cyanopyrazin-2-ylamino)-lH-pyrazol-5-yl)-3- methoxyphenoxy)propylcarbamate (1430 g, 3.07 mol) is slurried with acetone (21.5 L) in a 30 L reactor. Methanesulfonic acid (1484 g, 15.36 mol) is added through an addition funnel in a moderate stream. The slurry is warmed to reflux at about 52 ⁰C for 1 to 3 h and monitored for reaction completion by HPLC analysis. The completed reaction is cooled from reflux to 15 to 20 ⁰C over 4.5 h. The yellow slurry of 2-pyrazinecarbonitrile, 5-[[5-[-[2-(3-aminopropyl)-6-methoxyphenyl]-lH-pyrazol-3-yl]amino] dimesylate salt is filtered, rinsed with acetone (7 L) and dried in a vacuum oven. The dimesylate salt, (1608 g, 2.88 mol) is slurried in water (16 L). Sodium hydroxide (aqueous 50%, 228 g, 2.85 mol) is slowly poured into the slurry. The slurry is -36- heated to 60 ⁰C and stirred for one hour. It is then cooled to 16 ⁰C over 4 h and filtered. The wet filter cake is rinsed with acetone (4 L) and dried to constant weight in a vacuum oven at 40 ⁰C to provide 833 g (94%) of 2-pyrazinecarbonitrile, 5-[[5-[-[2-(3- aminopropyl)-6-methoxyphenyl]-lH-pyrazol-3-yl]amino] monomesylate monohydrate. mp 222.6 ⁰C; ES/MS m/z 366.2 [M+l]⁺.

Example 5a

2-Pyrazinecarbonitrile, 5-[[5-[-[2-(3-aminopropyl)-6-methoxyphenyl]-lH-pyrazol-3- yl] amino] monomesylate monohydrate (Chemical Abstracts nomenclature)

Crude 2-pyrazinecarbonitrile, 5 -[ [5 – [- [2-(3 -aminopropyl)-6-methoxyphenyl]- IH- pyrazol-3-yl] amino] monomesylate monohydrate is purified using the following procedure. The technical grade 2-pyrazinecarbonitrile, 5-[[5-[-[2-(3-aminopropyl)-6- methoxyphenyl]-lH-pyrazol-3-yl] amino] mono mesylate mono hydrate (1221 g, 2.55 mol) is slurried in a solvent mixture of 1: 1 acetone/water (14.7 L). The solid is dissolved by warming the mixture to 50 – 55 ⁰C. The solution is polish filtrated while at 50 – 55 ⁰C through a 0.22μ cartridge filter. The solution is slowly cooled to the seeding temperature of about 42 – 45 ⁰C and seeded. Slow cooling is continued over the next 30 – 60 min to confirm nucleation. The thin slurry is cooled from 38 to 15 ⁰C over 3 h. A vacuum distillation is set up and the acetone removed at 110 – 90 mm and 20 – 30 ⁰C. The mixture is cooled from 30 to 15 ⁰C over 14 h, held at 15 ⁰C for 2 h, and then filtered. The recrystallized material is rinsed with 19: 1 water/acetone (2 L) and then water (6 L) and dried to constant weight in a vacuum oven at 40 ⁰C to provide 1024 g (83.9%) of the title compound, mp 222.6 ⁰C; ES/MS m/z 366.2 [M+l]⁺. X-ray powder diffraction (XRPD) patterns may be obtained on a Bruker D8

Advance powder diffractometer, equipped with a CuKa source (λ=l.54056 angstrom) operating at 40 kV and 40 mA with a position-sensitive detector. Each sample is scanned between 4° and 35° in °2Θ ± 0.02 using a step size of 0.026° in 2Θ ± 0.02 and a step time of 0.3 seconds, with a 0.6 mm divergence slit and a 10.39 mm detector slit. Primary and secondary Soller slits are each at 2°; antiscattering slit is 6.17 mm; the air scatter sink is in place. -37-

Characteristic peak positions and relative intensities:

Differential scanning calorimetry (DSC) analyses may be carried out on a Mettler- Toledo DSC unit (Model DSC822e). Samples are heated in closed aluminum pans with pinhole from 25 to 350 ⁰C at 10 °C/min with a nitrogen purge of 50 mL/min. Thermogravimetric analysis (TGA) may be carried out on a Mettler Toledo TGA unit (Model TGA/SDTA 85Ie). Samples are heated in sealed aluminum pans with a pinhole from 25 to 350 ⁰C at 10 ⁰C /min with a nitrogen purge of 50 mL/min.

The thermal profile from DSC shows a weak, broad endotherm form 80 – 140⁰C followed by a sharp melting endotherm at 222 ⁰C, onset (225 ⁰C, peak). A mass loss of 4% is seen by the TGA from 25 – 140 ⁰C.

PATENT

US 20110144126

WO 2017015124

WO 2017100071

WO 2017105982

WO 2016051409

Clip

science 2017, 356, 1144

Kilogram-Scale Prexasertib Monolactate Monohydrate Synthesis under Continuous-Flow CGMP Conditions

  

References

REFERENCES

1: Zeng L, Beggs RR, Cooper TS, Weaver AN, Yang ES. Combining Chk1/2 inhibition with cetuximab and radiation enhances in vitro and in vivo cytotoxicity in head and neck squamous cell carcinoma. Mol Cancer Ther. 2017 Jan 30. pii: molcanther.0352.2016. doi: 10.1158/1535-7163.MCT-16-0352. [Epub ahead of print] PubMed PMID: 28138028.

2: Ghelli Luserna Di Rorà A, Iacobucci I, Imbrogno E, Papayannidis C, Derenzini E, Ferrari A, Guadagnuolo V, Robustelli V, Parisi S, Sartor C, Abbenante MC, Paolini S, Martinelli G. Prexasertib, a Chk1/Chk2 inhibitor, increases the effectiveness of conventional therapy in B-/T- cell progenitor acute lymphoblastic leukemia. Oncotarget. 2016 Aug 16;7(33):53377-53391. doi: 10.18632/oncotarget.10535. PubMed PMID: 27438145; PubMed Central PMCID: PMC5288194.

3: King C, Diaz HB, McNeely S, Barnard D, Dempsey J, Blosser W, Beckmann R, Barda D, Marshall MS. LY2606368 Causes Replication Catastrophe and Antitumor Effects through CHK1-Dependent Mechanisms. Mol Cancer Ther. 2015 Sep;14(9):2004-13. doi: 10.1158/1535-7163.MCT-14-1037. PubMed PMID: 26141948.
4: Hong D, Infante J, Janku F, Jones S, Nguyen LM, Burris H, Naing A, Bauer TM, Piha-Paul S, Johnson FM, Kurzrock R, Golden L, Hynes S, Lin J, Lin AB, Bendell J. Phase I Study of LY2606368, a Checkpoint Kinase 1 Inhibitor, in Patients With Advanced Cancer. J Clin Oncol. 2016 May 20;34(15):1764-71. doi: 10.1200/JCO.2015.64.5788. PubMed PMID: 27044938.

Prexasertib

Clinical data
Pregnancy category	IV
ATC code	none
Identifiers
IUPAC name[show]
CAS Number	1234015-52-1
ChemSpider	32738771
UNII	820NH671E6
Chemical and physical data
Formula	C18H19N7O2
Molar mass	365.40 g·mol−1
3D model (JSmol)	Interactive image
SMILES[hide] C1=C(C(=C(C=C1)OC)C1=CC(=NN1)NC1=NC=C(N=C1)C#N)OCCCN

////////////Prexasertib, прексасертиб , بريكساسيرتيب , 普瑞色替 , PHASE 2, LY-2606368, LY 2606368