Methanol → 6-(2-Chlorophenyl)-1,8-dichloro-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid

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Reaction Steps

A solution of 2 g (0.005 mole) of 6-(2-chlorophenyl)-1,8-dichloro-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid, methyl ester 0.7 g (0.012 mole) of potassium hydroxide, 60 ml of methanol and 2 ml of water was refluxed under argon for 2.5 hrs. The solution was evaporated in vacuo at 50°-60°. An aqueous solution of the residue was acidified with acetic acid to give a gelatinous, white precipitate. The precipitate was collected by filtration, washed with water and air dried on the funnel overnight to give off-white solid. Recrystallization from a solution of ethanol and methylene chloride gave white plates with mp 250°-253° (dec).

Provenance & Evidence