Preparation method of JAK1 inhibitor Londamocitinib
By synthesizing the JAK1 inhibitor Londamocitinib, the clinical adverse reactions caused by non-selectiveness of existing JAK inhibitors were solved, and a high selective inhibition of JAK1 was achieved, providing a new way to treat asthma.
Patent Information
- Application Number
- CN202311826845.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-27
- Publication Date
- 2025-06-27
AI Technical Summary
The inhibition of JAK-STAT signaling by existing JAK inhibitors such as tofatinib and baricitinib is nonselective and may lead to clinically severe adverse reactions. It is necessary to develop inhibitors with high selectivity and high efficiency for JAK1 to reduce the incidence of adverse events.
Through a series of chemical reactions, the JAK1 inhibitor Londamocitinib, including suzuki coupling reaction, debenzenesulfonyl protecting group and other steps, the compound Londamocitinib with high selectivity and excellent pharmacopolytic properties was prepared.
A high selective inhibition of JAK1 was achieved, reducing the risk of clinical adverse events, and providing a new therapeutic strategy for the treatment of asthma.
Smart Images
Figure CN120208928A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of pharmaceutical chemical synthesis and relates to a new preparation method of the JAK1 inhibitor Londamocitinib. Background Art
[0002] JAK-STAT cytokines are crucial for immune regulation. When the JAK-STAT signaling pathway is continuously activated by cytokines, it is likely to lead to the occurrence of chronic inflammatory diseases such as asthma, and also cause cancer and tissue damage. JAK kinases belong to non-receptor tyrosine kinases. It contains four members: JAK1, JAK2, JAK3, and TyK2. However, the combinations between its different members form intracellular signal adaptor proteins for different cytokine receptors, and thus correspondingly control different cytokine pathways. The sequences between the members are conserved. Marketed drugs such as Pfizer's tofacitinib and Eli Lilly's baricitinib inhibit JAK-STAT signals non-selectively, which may be associated with serious clinical adverse reactions. Currently, JAK inhibitors have evolved into selective inhibitors that only inhibit one or more JAK family members. In theory, it may reduce the incidence of clinical adverse events.
[0003] By studying the roles of JAK1 and JAK3 in mediating IL-4 signal transduction in T cells and myeloid cells, it was found that both JAK1 and JAK3 are involved in IL-4 signal transduction. However, JAK1 may be more important than JAK3 in the activation of myeloid cells and the regeneration of monocyte-derived inflammatory dendritic cells, and these are all key factors recognized in IL-4-driven asthma. This finding provides important insights into the molecular mechanism of asthma pathogenesis and suggests that targeting JAK1 signal transduction may be a promising therapeutic strategy for treating asthma. Through rational drug design, a potent, highly selective, and inhalable JAK1 inhibitor compound Londamocitinib with excellent properties in terms of pharmacokinetics, etc. was obtained. Its high selectivity for JAK1 is 1000 times that of JAK2, and it is currently undergoing phase II clinical trials for the treatment of asthma. Summary of the Invention
[0004] In view of the above situation, the preparation of the JAK1 inhibitor Londamocitinib is very important. The inventors of the present invention solved the technical problems of this compound through experimental research, and its reaction route is as follows:
[0005]
[0006] The present invention includes the following steps:
[0007] (a) The compound (R)-N-(3-(5-fluoro-2-(methylsulfonyl)pyrimidin-4-yl)-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (2) is obtained by the Suzuki coupling reaction of the raw material 4-halo-5-fluoro-2-(methylsulfonyl)pyrimidine (1) and (R)-3-methoxy-2-(4-methylpiperazin-1-yl)-N-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-tosyl-1H-indol-7-yl)propanamide (5).
[0008]
[0009] Among them, X = Br, Cl, I
[0010] (b) The compound (2) reacts with 2-fluoro-3-(methylsulfonyl)aniline (6) to obtain the compound (R)-N-(3-(5-fluoro-2-((2-fluoro-3-(methylsulfonyl)phenyl)amino)pyrimidin-4-yl)-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (3).
[0011]
[0012] (c) Finally, the p-toluenesulfonyl protecting group is removed to obtain the target compound Londamocitinib (4).
[0013] Specific examples
[0014] The present invention will be further described and illustrated below by examples, but the content of the present invention is not limited thereby.
[0015] Preparation of the intermediate (R)-3-methoxy-2-(4-methylpiperazin-1-yl)-N-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-tosyl-1H-indol-7-yl)propanamide
[0016] Step A
[0017] In a 100 mL round-bottom flask, 7-nitro-1H-indole (0.54 g, 30.0 mmol) and tetrabutylammonium bromide (1.07 g, 0.33 mmol) were dissolved in CH2Cl2 (10 mL) and cooled in an ice-water bath. An aqueous NaOH solution (10 M, 1 mL) was added dropwise to the above solution, and the temperature was maintained for 30 minutes. Then, 4-methylbenzenesulfonyl chloride (0.95 g, 5 mmol) was added. The reaction system was allowed to warm to room temperature naturally for 16 h. After the reaction was completed, it was diluted with CH2Cl2, and the organic phase was successively mixed with water and washed with 10% aqueous K2CO3 solution, water, 1 M dilute hydrochloric acid, and saturated NaCl aqueous solution, dried over anhydrous Na2SO4, filtered and concentrated to obtain the product (1 g, yield 95%). LC-MS (ESI): m / z = 316.3 [M+H] +
[0018] Step B
[0019] Under nitrogen at room temperature, 7-nitro-1-tosyl-1H-indole (0.98 g, 3.09 mmol) was added to THF / EtOH 2:1 (15 mL). The suspension was stirred and an aqueous solution (10 mL) of 10% Pd / C (0.3 g, 3.1 mmol) and ammonium formate (1.17 g, 18.5 mmol) was added. The reaction mixture was slowly heated to 70 °C and stirred for 30 minutes. 12 g of activated carbon was added and stirred for 15 minutes. The reaction mixture was cooled to 40 °C and filtered under nitrogen in a Buchner funnel. The filter cake was washed with THF / EtOH (4 mL). The filtrate was concentrated to reduce the volume. The resulting reaction solution was cooled to room temperature and filtered under nitrogen. The solid was washed with water (2 vol) and ethanol (2 vol) and dried in vacuo at 40 °C to obtain 1-tosyl-1H-indole-7-amine (0.70 g, yield 80%) as a light brown solid. LC-MS (ESI): m / z = 286.4 [M+H] +
[0020] Step C
[0021] At room temperature, (R)-3-methoxy-2-(4-methylpiperazin-1-yl)propanoic acid dihydrochloride (0.14 g, 0.4 mmol) was added to a 10 L low-temperature reactor, and then 3 mL of DMF was added. 1-Tosyl-1H-indol-7-amine (0.10 g, 0.36 mmol) was added to the light brown solution. The resulting dark brown transparent solution was cooled to -20 °C (jacket set to -30 °C). 2 mL of pyridine was added to the reactor within 5 minutes. No obvious exotherm was observed. At -20 °C, propanephosphonic anhydride (T3P) dissolved in DMF (0.6 mL, 1.08 mmol) was slowly added, with the temperature not exceeding -13 °C. Due to the exothermic reaction, the jacket was set to -40 °C. The addition process was completed after 75 minutes. After adding 2 / 3, a sample was taken and SFC-MS was run, and the conversion was almost complete. The conversion was completed after complete addition. Final analysis by UPLC-MS. Within 1 h, the reaction mixture was quenched by slowly adding water at -15 °C. The quenched mixture was stirred at -15 °C for another 30 minutes. In a larger reactor, 8.5% NaHCO3 (4 mL) was prepared in advance and cooled to +5 °C. To minimize the generation of foam, the reaction mixture was slowly transferred to the reactor containing 8.5% NaHCO3 (4 mL). One hour after the addition, 20 mL of saturated sodium bicarbonate solution was added, and the product began to precipitate from the clear solution. The precipitate mixture was stirred at +5 °C for 30 minutes. Filtration was carried out, but the product was not suitable for filtration, and this process took a rather long time to complete. The crude product was loaded into the reactor, and 4 mL of acetonitrile was added. The mixture was stirred under reflux, and another 2 mL of acetonitrile was added to increase the solubility of the product. The opaque solution was clarified by filtration, and some crystallization began. The filtered transparent organic matter was transferred to another reactor, and the volume was reduced to 1 mL. Crystallization was started by slowly cooling to 5 °C under reflux within 24 hours. The product was filtered off and washed with 2 volumes of cold acetonitrile. The product was dried under reduced pressure at 40 °C overnight to obtain compound (R)-3-methoxy-2-(4-methylpiperazin-1-yl)-N-(1-tosyl-1H-indol-7-yl)propanamide (0.11 g, yield 65%). LC-MS (ESI): m / z = 470.6 [M+H] +
[0022] Step D
[0023] (R)-3-Methoxy-2-(4-methylpiperazin-1-yl)-N-(1-tosyl-1H-indol-7-yl)propanamide (1.06 g, 2.26 mmol) was dissolved in CCl4 (15 mL). At 80 °C, bromine (1.16 mL, 22.57 mmol) was added dropwise, and the resulting solution was stirred at 80 °C for 6 hours. The mixture was cooled to room temperature, concentrated, and the residue was washed with ethyl acetate to obtain (R)-N-(3-bromo-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (1.09 g, yield 88%), as a brown solid; LC-MS (ESI): m / z = 549.5 [M+H] +
[0024] Step E
[0025] (R)-N-(3-Bromo-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (428 mg, 0.78 mmol), Pd(dppf)Cl2 (58 mg, 0.08 mmol), potassium acetate (228 mg, 2.33 mmol) and bis(pinacolato)diboron (295 mg, 1.17 mmol) were mixed in DME (5 mL). The air in the mixture was removed by blowing nitrogen, then sealed and reacted at 105 °C for 2 hours. After the reaction was completed, the mixture was filtered to remove solid impurities. The filtrate was concentrated to remove the solvent, and the residue was purified by silica gel column chromatography to obtain (R)-3-methoxy-2-(4-methylpiperazin-1-yl)-N-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-tosyl-1H-indol-7-yl)propanamide (428.5 mg, yield 90%). LC-MS (ESI): m / z = 596.6 [M+H] +
[0026] Example 1
[0027]
[0028] Step A
[0029] A mixture of 4-halo-5-fluoro-2-(methylsulfonyl)pyrimidine (0.38 g, 1.81 mmol) and Cs2CO3 (1.77 g, 5.440 mmol) in dioxane (75 mL) and H2O (25 mL) was degassed. Then Pd(dppf)Cl2 (133 mg, 0.18 mmol) and (R)-3-methoxy-2-(4-methylpiperazin-1-yl)-N-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-tosyl-1H-indol-7-yl)propanamide (1.41 g, 2.36 mmol) were added, and the mixture was stirred at 100 °C for 16 h under N2. After completion of the reaction, the reaction mixture was quenched with water (10 mL) and extracted with ethyl acetate (5 mL × 3). The combined organic layers were washed with saturated brine (5 mL × 2), dried over Na2SO4, filtered and concentrated under reduced pressure. The crude product was purified by column chromatography to give (R)-N-(3-(5-fluoro-2-(methylsulfonyl)pyrimidin-4-yl)-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (1.12 g, yield 96%). LC-MS (ESI): m / z = 644.7 [M+H] +
[0030] Step B
[0031] To a solution of 2-fluoro-3-(methylsulfonyl)aniline (0.97 g, 5.1 mmol) in THF (15 mL) and DMF (3 mL) at -78 °C was added 60% NaH (216 mg, 5.4 mmol). The mixture was stirred at room temperature for about 10 min. (R)-N-(3-(5-fluoro-2-(methylsulfonyl)pyrimidin-4-yl)-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (3.29 g, 5.1 mmol) was added to the mixture at -78 °C, and then the mixture was stirred at -78 °C for 15 min. The reaction mixture was quenched with 1 M HCl solution (6 mL), and the crude mixture was extracted with EtOAc (60 mL). The organic layer was concentrated under reduced pressure and purified by column chromatography to give (R)-N-(3-(5-fluoro-2-((2-fluoro-3-(methylsulfonyl)phenyl)amino)pyrimidin-4-yl)-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (1.15 g, 30%). LC-MS (ESI): m / z = 753.8 [M+H] +
[0032] Step C
[0033] (R)-N-(3-(5-Fluoro-2-((2-fluoro-3-(methylsulfonyl)phenyl)amino)pyrimidin-4-yl)-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (0.83 g, 1.1 mmol) was charged into a 5 L reactor at room temperature. THF (2 mL) and 3.8 M NaOH (aqueous solution) (10 mL) were added. The mixture was heated to 75 °C and stirred under reflux for 48 h. THF (5 vol) and heptane (5 vol) were charged into the reaction mixture. Then it was cooled to 17 °C and the solid was filtered on a Buchner funnel. The filter cake was washed with 1 M citric acid (4 mL until pH was neutral), water (5 x 2.5 mL until pH was neutral), and then with heptane / EtOAc (4 x 3.5 mL). The solid was dried under vacuum to obtain the target compound Londamocitinib (0.469 g, yield 71%). LC-MS (ESI): m / z = 599.67 [M+H] + 。 1 1H NMR (300 MHz, DMSO-d6): δ 2.14 (s, 3H), 2.25 - 2.44 (m, 4H), 2.55 - 2.67 (m, 2H), 2.69 - 2.79 (m, 2H), 3.26 - 3.79 (m, 9H), 7.04 (t, 1H), 7.42 - 7.55 (m, 2H), 7.62 (t, 1H), 8.19 (t, J = 7.3 Hz, 1H), 8.22 - 8.33 (m, 2H), 8.44 (d, 1H), 9.46 (s, 1H), 9.84 (s, 1H), 11.47 (s, 1H).
[0034] Table 1: 4-Halo-5-fluoro-2-(methylsulfonyl)pyrimidine (1) and (R)-3-methoxy-2-(4-methylpiperazin-1-yl)-N-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-tosyl-1H-indol-7-yl)propanamide (5) underwent a Suzuki coupling reaction to obtain the compound (R)-N-(3-(5-fluoro-2-(methylsulfonyl)pyrimidin-4-yl)-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (2)
[0035]
[0036]
[0037] The examples are only used to illustrate the embodiments of the present invention, but the present invention is not limited to the above examples. Without departing from the spirit and scope of the present invention, various changes and improvements will be made to the present invention, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the claims and their equivalents.
Claims
1. A preparation method of JAK1 inhibitor Londamocitinib, characterized in that, The specific steps are as follows: (1) The compound (R)-N-(3-(5-fluoro-2-(methylsulfonyl)pyrimidin-4-yl)-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (2) is obtained by the Suzuki coupling reaction of the raw material 4-halo-5-fluoro-2-(methylsulfonyl)pyrimidine (1) and (R)-3-methoxy-2-(4-methylpiperazin-1-yl)-N-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1-tosyl-1H-indol-7-yl)propanamide (5). (2) The compound (2) reacts with 2-fluoro-3-(methylsulfonyl)aniline (6) to obtain the compound (R)-N-(3-(5-fluoro-2-((2-fluoro-3-(methylsulfonyl)phenyl)amino)pyrimidin-4-yl)-1-tosyl-1H-indol-7-yl)-3-methoxy-2-(4-methylpiperazin-1-yl)propanamide (3). (3) Finally, the p-toluenesulfonyl protecting group is removed to obtain the target compound Londamocitinib (4).
2. The preparation method of a JAK1 inhibitor Londamocitinib according to claim 1, characterized in that, In step (1), for the raw material 4-halo-5-fluoro-2-(methylsulfonyl)pyrimidine, the halogen substituent is selected from chlorine, bromine, and iodine.
3. The preparation method of a JAK1 inhibitor Londamocitinib according to claim 1, characterized in that, In step (1), the reaction temperature of the Suzuki coupling reaction is selected from 10 - 200 °C, the reaction time is selected from 0 - 72 h, and the solvent is selected from one or more of diethyl ether, acetonitrile, THF, DMF, DME, 1,4-dioxane, H2O, NMP, DMA, DMSO, benzene, and toluene. The catalyst used in the reaction can be selected from one or more of bis(triphenylphosphine)-palladium dichloride, dichloro(η5-cyclopentadienyl)(1,2-bis(diphenylphosphino)ethane)palladium(II), dichloro(η5-cyclopentadienyl)(1,2-bis(diphenylphosphino)ethane)palladium(II) dichloromethane complex, Pd2(dba)3, pd(dppe)Cl2, tetrakis(triphenylphosphine)palladium, and dichloro(η5-cyclopentadienyl)(1,2-bis(diphenylphosphino)ethane)nickel(II), 0.01% - 20% (M / M molar ratio) of the compound. The base used in the reaction is selected from one of triethylamine, ethylenediamine, diisopropylethylamine, imidazole, piperidine, pyridine, CsCO3, KOAc, NaOAc, K2CO3, Na2CO3, Li2CO3, tBuOK, tBuONa, K3PO4, NaOH, KOH, and Ba(OH)2. The dosage is 1 - 10 times (M / M molar ratio). Purification can be selected from column chromatography, trituration, or recrystallization.
4. The preparation method of a JAK1 inhibitor Londamocitinib according to claim 1, characterized in that, In step (2), the reaction temperature is selected from -78 - 200 °C, and the solvent is selected from one or more of acetonitrile, THF, 1,4-dioxane, H2O, DMSO, DCM, and 1,2-dichloroethane. Purification can be selected from washing the filter cake during filtration, column chromatography, trituration, or recrystallization.
5. The preparation method of a JAK1 inhibitor Londamocitinib as described in claim 1, characterized in that, In step (3), the alcohol solvent used is selected from one or more of methanol, ethanol, isopropanol, and tert-butanol. The strong base reagent is selected from one or more of sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, sodium tert-butoxide, and potassium tert-butoxide. The molar ratio of the strong base used to the compound is (1-5):1, and the reaction conditions are reflux reaction for 10-72 hours.