Sodium borohydride → HCID 118431940, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-(5-bromo-thiophen-2-yl)-1-(2,4-difluoro-phenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid methyl ester (15.1 g, 37.6 mmol) prepared in Step 3 in methanol (125.3 mL), was slowly added sodium borohydride (6.4 g, 169.2 mmol) at 0° C. The reaction mixture was stirred at 80° C. for 18 hours, concentrated under reduced pressure, acidified by a 1N hydrochloric acid solution, and then extracted with dichloromethane. The extract was washed with brine, dried on anhydrous magnesium sulfate, and then concentrated under reduced pressure to give a yellow liquid residue. The resulting residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane=1/2) to give 12.9 g of the titled compound as a yellow liquid.

Provenance & Evidence