反应详情

温度

20 °C

Sodium bis(trimethylsilyl)amide (7.13 mL, 7.13 mmol) was added dropwise to cyclopentanethiol (0.761 mL, 7.13 mmol) in DMF (25 mL) under nitrogen. The resulting solution was stiffed at 20° C. for 30 minutes. A solution of tert-butyl 5-chloro-1-(4-(methoxycarbonyl)phenyl)-1H-pyrazole-4-carboxylate (Intermediate#9) (2 g, 5.94 mmol) in DMF (10 mL) was then added dropwise and the resulting mixture was stirred at 20° C. for 2 hours. The reaction mixture was diluted with EtOAc (200 mL), and washed sequentially with water (4×50 mL) and saturated brine (50 mL). The organic layer was dried over MgSO4, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution gradient 0 to 25% EtOAc in isohexane. Pure fractions were evaporated to dryness to afford tert-butyl 5-(cyclopentylthio)-1-(4-(methoxycarbonyl)phenyl)-1H-pyrazole-4-carboxylate (1.380 g, 57.7%) as a colourless oil which crystallised on standing.

1. washwashed sequentially with water (4×50 mL) and saturated brine (50 mL)
2. dry with materialThe organic layer was dried over MgSO4
3. filtrationfiltered
4. customevaporated
5. customto afford crude product
6. customThe crude product was purified by flash silica chromatography, elution gradient 0 to 25% EtOAc in isohexane
7. customPure fractions were evaporated to dryness