Acetic Anhydride → 2-(2-Acetylhydrazino)-7-chloro-5-phenyl-3H-1,4-benzodiazepine

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Reaction Steps

To a solution of 1.4 parts of 7-chloro-2-hydrazino-5-phenyl-3H-1,4-benzodiazepine in 30 parts by volume of chloroform is added with stirring 0.47 part by volume of acetic anhydride. The mixture is stirred for 1 hour and washed with a saturated aqueous solution of sodium bicarbonate and then with water. The chloroform layer is dried over sodium sulfate and the solvent is evaporated. Addition of methanol yields 2-(2-acetylhydrazino)-7-chloro-5-phenyl-3H-1,4-benzodiazepine as white crystals. Recrystallization from a mixture of chloroform and methanol yields powdery crystals melting at 202° C to 204° C (effervescence).

Provenance & Evidence