Acetic Anhydride → HCID 21265973, compound

Participants

Reaction Steps

0.96 ml of acetic anhydride was added dropwise to a solution of 1.36 g of 8-chloro-6-(2-fluorophenyl)-4H-imidazo[1,2-a][1,4]benzodiazepine-2-methanol in 30 ml of pyridine. The reaction mixture was stirred at room temperature for 70 h. and then evaporated in a vacuum. The residue was treated with saturated aqueous sodium hydrogen carbonate solution and this was extracted twice with dichloromethane. The dichloromethane extracts were dried over sodium sulphate and the solution was chromatographed over 50 g of silica gel. 1.4 g of an oil were eluted with dichloromethane/ethanol 197:3 and this was crystallized from diethyl ether/diisopropyl ether. There were obtained 2.1 g of 2-acetoxymethyl-8-chloro-6-(2-fluorophenyl)-4H-imidazo [1,2-a][1,4]benzodiazepine of m.p. 134-136° C. which was converted into the hydrochloride.

Provenance & Evidence