Tibremciclib

cas 2397678-18-9, GTPL12881

CRB7BT5JDQ

518.6 g/mol, C₂₈H₃₂F₂N₈

N-[5-[(4-ethylpiperazin-1-yl)methyl]pyridin-2-yl]-5-fluoro-4-[(1R)-6-fluoro-1-methyl-1,2,3,4-tetrahydropyrido[1,2-a]benzimidazol-8-yl]pyrimidin-2-amine

Tibremciclib is a CDK4 inhibitor with antineoplastic activity^[1].

• Originator Betta Pharmaceuticals Co Ltd
• Class Antineoplastics; Small molecules
• Mechanism of Action Cyclin-dependent kinase 4 inhibitors; Cyclin-dependent kinase 6 inhibitors

• Phase III Breast cancer; Solid tumours

13 Sep 2024 Efficacy and adverse event data from a phase III trial in Breast cancer presented at the 49th European Society for Medical Oncology Congress 2024 (ESMO-2024)

• 30 Jun 2023Phase-III clinical trials in Breast cancer (Metastatic disease, Late-stage disease, Combination therapy, Second-line therapy or greater) in China (PO) (NCT05433480)
• 02 Jun 2023Efficacy, adverse events and PK data from a phase I trial in Solid tumours presented at the 59th Annual Meeting of the American Society of Clinical Oncology (ASCO-2023)

Cyclin-dependent kinases (CDKs) are a class of serine / threonine protein kinases that participate in the regulation of the cell cycle, transcription initiation, and control of certain specific metabolic cascades. Different CDKs and cyclins form CDK-cyclin complexes. If the CDK activity is dysregulated, it will directly or indirectly cause uncontrolled cell proliferation, genomic instability (increased DNA mutation, chromosome deletion, etc.) and chromosomal instability (change in chromosome number). )Wait.

The CDKs family has identified more than 20 subtypes. CDK1, CDK2, CDK4, and CDK6 are involved in cell cycle regulation; CDK7, CDK8, CDK9, and CDK11 are involved in transcription regulation; and other kinases include CDK3 and CDK5. Among them, CDK4 / 6 (cyclin-dependent kinases 4 and 6) is a key factor in regulating the cell cycle. Cancer-related cell cycle mutations mainly exist in the G1 and G1 / S phase transformation. CDK4 / 6 binds to CyclinD A complex with kinase activity is formed and phosphorylation of the tumor suppressor gene Rb product pRb releases the bound transcription factor E2F to initiate transcription of genes related to the S phase, prompting cells to pass the checkpoint and transfer from the G1 phase to the S phase. The specific activation of CDK4 / 6 is closely related to the proliferation of some tumors. About 80% of human tumors have abnormalities in the cyclin D-CDK4 / 6-INK4-Rb pathway. CDK4 / 6 inhibitors block the cell cycle in the G1 phase, thereby inhibiting tumor proliferation.

The development of drugs targeting CDK4 / 6 kinases is a significant area. The advantages of anti-tumor targets are: (1) Most proliferating cells rely on CDK2 or CDK4 / 6 to proliferate, but CDK4 / 6 inhibitors do not show Cytotoxicity of “pan-CDK inhibitors”, such as bone marrow suppression and intestinal response; (2) Preclinical experiments show that if the level of cyclin D or the inactivation of P16INK4a can increase the sensitivity of cells to drugs, due to tumors Compared with normal cells, cells have the above phenomenon, so the targeting of drugs is increased to a certain extent.

PCT International Application PCT / CN2017 / 117950 describes a class of benzimidazole derivatives that are used as CDK4 / 6 protein kinase inhibitors, and most of these compounds effectively inhibit CDK4 and CDK6. Because there are still unmet needs in the treatment options for kinase-mediated diseases, here we further screen the salt forms and crystal forms of benzimidazole derivatives to meet the medical needs of patients.

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Patent

Betta Pharmaceuticals Co., Ltd., WO2019242719

https://patents.google.com/patent/WO2019242719A1/en

Synthesis of 1-A1-01 (Step 1)

In a 50L reactor, add 20L of dichloromethane (DCM), 1-A1-S1 (300g), and triethylamine (390g). While stirring, lower the temperature to below -5 ° C, and add benzyl chloroformate / Cbz- Cl (570 g) was added dropwise for 5 hours, and the temperature was naturally raised to room temperature. TLC (ethyl acetate: n-hexane = 1: 3) was monitored until the reaction was completed. Water (1.5 L) was added, and concentrated hydrochloric acid (80 mL) was slowly added dropwise to control the pH to 1-2. The solution was allowed to stand and separate. The organic phase was washed with 15 L of water, dried over anhydrous sodium sulfate for 0.5 hours, filtered to remove the desiccant, and collected the filtrate. And concentrated to obtain 730 g of light yellow oily liquid, which is crude 1-A1-01, yield 95.4%

Synthesis of 1-A1-02 (Step 2)

720mL of DCM, N, N-dimethylsulfoxide (90g) was added to a 20L reaction flask, protected by nitrogen, and the temperature was lowered below -65 ° C under stirring, and oxalyl chloride (106g) was added dropwise. The addition was completed in 2 hours. Stir for 20 minutes under heat preservation; add 1-A1-01’s dichloromethane solution (143g / 500mL DCM) dropwise. After 40 minutes, the addition is complete and the reaction is held for 15 minutes. Controlled at this temperature, TEA was added dropwise. After the addition was completed for 2 hours, the temperature was naturally raised to -20 ° C. 250 L of water was added to the system. The pH of the system was adjusted to 1-2 with hydrochloric acid. × 2) Washed, dried over anhydrous sodium sulfate, filtered to remove the desiccant, collected the filtrate and concentrated to obtain 432 g of a yellow oily liquid, which is the crude product 1-A1-02, which was directly used in the next reaction.

Synthesis of 1-A1-03 (Step 3)

In a stirred state, 400 mL of tetrahydrofuran (THF) and potassium tert-butoxide (215 g) were sequentially added to a 1 L reaction kettle, the temperature was lowered to 5-15 ° C., and triethyl phosphoryl acetate (430 g) was added dropwise. The dropwise addition was completed in 50 minutes. At a controlled temperature of 15 ° C, a tetrahydrofuran solution of 1-A1-02 (431 g / 100 mL of THF) was added dropwise. After the dropwise addition was completed for 1 hour, TLC (ethyl acetate: n-hexane = 1: 3) was monitored to complete the reaction, and the system was added. Saturated aqueous sodium chloride solution (1.5L), allowed to stand and separate, and collected the tetrahydrofuran phase; the aqueous phase was extracted with dichloromethane (2L), and the organic phases were combined and dried over anhydrous sodium sulfate for 0.5 hours, and the drying agent was removed by filtration. The filtrate was collected and concentrated, and the concentrate was purified by column chromatography to obtain 390 g of a pale yellow oily liquid, which was 1-A1-03 product.

Synthesis of 1-A1-041 (step 4)

In a 5L reactor, an aqueous solution of sodium hydroxide (301 g / 1.5 L of water) was added to a tetrahydrofuran (601 g / 2.3 L of THF) solution of 1-A1-03, and the mixture was heated to reflux for 3-4 hours to stop the reaction. The temperature was lowered to 40-50 ° C, and the layers were left to stand. The organic phase (THF) was collected and concentrated to a large amount of solids; the solids were dissolved by adding water (20L), and the aqueous phase was sequentially treated with methyl tert-butyl ether (2L) and ethyl acetate. Ester (2L), methyl tert-butyl ether (2L) washing; the aqueous phase was adjusted to pH 1-2 with concentrated hydrochloric acid, extracted twice with ethyl acetate (1.5L, 3L), the organic phases were combined, and anhydrous sulfuric acid was used Sodium was dried for 0.5 hours; the desiccant was removed by filtration, and the filtrate was collected and concentrated to a large amount of solids. The solids were added with isopropyl ether (3L) and slurried for 2 hours. The solids were collected by filtration and the solids were rinsed with isopropyl ether (1L). The solid was air-dried at 50 ° C for 3-4 hours to obtain 331 g of a pale yellow solid, which is a 1-A1-041 product with a yield of 52.7%.

Synthesis of 1-051 (step 5)

In a stirred state, 1-A1-041 (600g), methanol (25L), and concentrated sulfuric acid were added to a 50L reactor, and the reaction was heated under reflux for 3-4 hours. After the reaction was completed, the temperature was reduced to room temperature. Dichloromethane (15L) was added to the concentrate, and the pH was adjusted to 9-10 with an aqueous solution of potassium carbonate. The organic phase was collected by stirring, standing, and separating. The organic phase was dried over anhydrous sodium sulfate for 0.5 hours. The desiccant was removed by filtration and the filtrate was collected. And concentrated to obtain 6.37 kg of off-white solid, which is 1-A1-051 product, with a yield of 97.3%.

Synthesis of 1-A1 (step 6)

In a 2L hydrogenation kettle, add 1-A1-051 (500g), methanol (1.8L), and palladium on carbon. The system replaces nitrogen 3 times and hydrogen 3 times in sequence. The system maintains a hydrogen atmosphere, and the temperature is increased to 85 ° C and the pressure is 3.0. The reaction was carried out at Mpa for 3 hours, and the reaction was completed. The temperature was lowered to room temperature, the palladium on carbon was removed by filtration, and the organic phase was collected and concentrated until a large amount of light yellow solid appeared. Isopropyl ether (3L) was added to freeze (-20 ° C) for crystallization, and the solid product was collected by filtration. Ether (500 mL) was rinsed to obtain 234 g of a pale yellow solid, which was a 1-A1 product with a yield of 90.5%.

Synthesis of 1-A2 (Step 7)

In a stirred state, 1-A1 (200g), 4-bromo-2,6-difluoroaniline (410g), and toluene (1.2L) were added to a 50L reactor, and phosphorus oxychloride (413g) was added dropwise to the system. The addition was completed in 1 hour. Triethylamine was added dropwise under an ice bath, and the addition was completed in 1 hour. The temperature was raised to 110 ° C, and the reaction was performed for 1 hour. Reduce the temperature of the system to 2-10 ° C, add 1L of water, adjust the pH = 9-10 with saturated potassium carbonate aqueous solution, extract twice with ethyl acetate (1.5L, 1L), and combine the organic phases with 2L saturated sodium chloride aqueous solution. Wash, dry with anhydrous sodium sulfate for 0.5 hours, remove the desiccant by filtration, collect the filtrate and concentrate to the appearance of a solid product, add isopropyl ether (1L) to beat the solid for 10 minutes, filter, and collect 460 g of a yellow solid as a 1-A2 product.

Synthesis of 1-A3 (step eight)

Under stirring, 1-A2 (450g), N, N-dimethylformamide (2L), and cesium carbonate (700g) were added to the reaction kettle, and the reaction was heated to 110 ° C for 24 hours, and the reaction was detected by TLC. Ethyl acetate (3L) was added to the system, and solid impurities were removed by filtration. The filtrate was washed with a saturated sodium chloride aqueous solution (1L × 5), and the organic phase was dried over anhydrous sodium sulfate for 0.5 hours, concentrated to the appearance of a large amount of solid, Butyl ether (1L × 2) was beaten for 30 minutes, and 382 g of pale yellow solid product was obtained by filtration, that is, 1-A3, and the yield was 90.10%.

Synthesis of 1-01 (step 9)

With stirring, 1-A3 (380 g), pinacol diborate (400 g), potassium acetate (340 g), palladium acetate (6 g), tricyclohexyl phosphorus (7 g), and 1,4-dioxane were sequentially added. The ring was added to the reaction kettle, protected by nitrogen, and heated to 90 ° C for 2 hours. TLC was monitored until the reaction was complete. The temperature was reduced to room temperature, and the filtrate was concentrated to remove a large amount of 1,4-dioxane. The concentrate was purified by n-hexane and dichloromethane column chromatography, and n-hexane (1.2 L) was slurried for 1 hour to obtain 334 g of a gray solid. That is 1-01, and the yield is 70.10%.

Synthesis of 1-02 (step 10)

Under stirring, take 1-01 (128g), 1,4-dioxane (1L), 1-S3 (85g), potassium carbonate (110g), and purified water and add them to a 2L three-necked flask in sequence. [1,1′-Bis (diphenylphosphine) ferrocene] palladium dichloromethane complex (Pd (dppf) Cl ₂ .DCM) was added. The temperature was raised to 60 ° C. After 4 hours of reaction, the reaction was complete. The reaction solution was cooled to room temperature, and concentrated under reduced pressure to remove most of 1,4-dioxane. Dichloromethane (1.5 L) and purified water (1.1 L) were added, stirred, and allowed to stand and separate. The layers were separated, and water was added. The phases were extracted with dichloromethane (10 L), the organic phases were combined, washed with 0.5% dilute hydrochloric acid (1 L x 2), saturated aqueous sodium chloride solution (1 L), and the layers were separated. The organic phase was dried over anhydrous sodium sulfate (500 g), filtered to remove the drying agent, and the filtrate was concentrated under reduced pressure. Ethyl acetate (0.5 L) was added to the concentrate and the mixture was stirred for 30 minutes to precipitate a solid. After filtration, the obtained solid was rinsed with ethyl acetate (0.5 L) and dried under vacuum at 45 ° C for 3 hours to obtain 120 g of a yellow solid.

Synthesis of 1-03 (step 11)

Under stirring, take 1-02 (100g), 1,4-dioxane (1L), 1-C2 (80g), and cesium carbonate (163g) into a 2L three-necked bottle in sequence, protected by nitrogen, and add palladium acetate ( 2g) and 4,5-bisdiphenylphosphine-9,9-dimethylxanthracene (Xantphos) (4g), heated to 85 ° C. until the reaction was complete. The reaction solution was cooled to room temperature and filtered to obtain a solid product. The solid was rinsed with ethyl acetate, and then added to a mixed system of dichloromethane (1.5 L) and purified water (1.1 L), stirred, allowed to stand, and separated into layers. The aqueous phase was extracted with dichloromethane (700 mL). The organic phases were combined and washed with purified water (700 mL x 2). The organic phase was dried by adding anhydrous sodium sulfate (700 g), filtered to remove the desiccant, and the filtrate was concentrated. Methanol (0.5 L) was added, heated to 55-65 ° C. and stirred for 0.5 hours, lowered to room temperature, and filtered. The solid product was filtered and rinsed with 500 mL of ethyl acetate. The solid was dried under vacuum at 45 ° C for 8 hours to obtain 111.79 g of a pale yellow solid 1-03.

Synthesis of compound II (step twelve)

Under stirring, take 1-03 (500g) and anhydrous methanol (3.8L), add them to a 10L reactor in sequence, and heat to 65 ° C. After the reaction system is clarified for 0.5 hours, add L-tartaric acid in methanol (150.89) dropwise. g of tartaric acid is dissolved in 500mL of anhydrous methanol), and the dropping time is controlled to be 45 to 60 minutes. After the addition is complete, the reaction is kept at 65 ° C for 4 hours. ), Control the dropwise addition time to 30 to 45 minutes. After the dropwise addition is complete, hold the reaction at 65 ° C for 1 hour. Continue to dropwise add L-tartaric acid in methanol (36.55g of tartaric acid dissolved in 250mL of anhydrous methanol) and control the dropwise addition time to 30. To 45 minutes, the dropwise addition was completed. The temperature was kept at 65 ° C for 1.5 hours, and the heating was stopped. The temperature was naturally lowered to 20-30 ° C, filtered, the filter cake was rinsed with methanol (400mL × 2), and dried at 45 ° C under vacuum for 36 hours. 530.64 g of crystalline powder was Compound II, which was identified by X-ray powder diffraction, and showed that the crystal form was Form A of Compound II.

WO2022199656 

WO2023131179

[1]. Wang Yiqian, et al. Crystal form of compound useful as CDK4/6 inhibitors for the treatment of cancer. World Intellectual Property Organization, WO2019242719 A1. 2019-12-26.

///Tibremciclib, GTPL12881, BETTA, PHASE 3, CANCER