Acetyl chloride → HCID 21183161, compound

Participants

Reaction Steps

A solution of 0.25 mL of acetyl chloride in 3 mL of dry dichloromethane was added slowly under nitrogen at 0° C. with stirring to a solution of 1.5 g (3.4 mmol) of 1-(1,1-dimethylethyl)-5-hydroxy-4-(2-methyl-4-methylsulfonyl-3-(4-methoxyphenyl)benzoyl)pyrazole and 0.52 mL of triethylamine in about 20 mL of dry dichloromethane. The mixture was allowed to warm to ambient temperature and stir for 2 hours and was then diluted with dichloromethane. The resulting solution was extracted with saturated aqueous sodium bicarbonate solution and with water, dried over magnesium sulfate, filtered, and concentrated by evaporation under reduced pressure. The residual yellow oil was chromatographed on silica gel eluting with a 50:50 mixture of ethyl acetate and hexane. The product fractions were combined and concentrated by evaporation under reduced pressure to obtain 1.03 g (62 percent of theory) of the title compound as a white powder melting at 160-163° C.

Provenance & Evidence