Benzoyl chloride → 1-Benzoyl-1,2,4,7-tetrahydro-5-methyl-7-(3-nitrophenyl)-2-oxopyrazolo[1,5-a]pyrimidine-6-carboxylic acid, 1-methylethyl ester

Participants

Reaction Steps

A suspension of 1,2,4,7-tetrahydro-5-methyl-7-(3-nitrophenyl)-2-oxopyrazolo[1,5-a]pyrimidine-6-carboxylic acid, 1-methylethyl ester (36 mg; 0.1 mmole) in dichloromethane (2 ml) and pyridine (1 ml) under argon was treated with benzoyl chloride (28 mg; 0.2 mmole). The reaction was allowed to stir for 30 minutes and then diluted with ethyl acetate. The resulting solution was washed with 1N hydrochloric acid, water, sodium bicarbonate and brine. It was dried over anhydrous magnesium sulfate and evaporated. The residue was purified by preparative thin layer chromatography (40% acetone in hexanes) and the product was crystallized from absolute ethanol to provide a solid, melting point 201°-203° C.

Provenance & Evidence