Hydrochloric Acid → (S)-7-fluoro-12,12a-dihydro-9-oxo-9H,11H-azeto[2,1-c]imidazo[1,5-a][1,4]-benzodiazepine-1-carboxylic acid

Participants

Reaction Steps

40.58 g (128.7 mmol) of ethyl (S)-7-fluoro-12,12a-dihydro-9-oxo-9H,11H-azeto-[2,1-c]imidazo[1,5-a][1,4]benzodiazepine-1-carboxylate, 300 ml of ethanol and 32.5 ml (130 mmol) of 4N sodium hydroxide solution were heated to reflux on a steam bath for 1.5 hours. The alcohol was evaporated on a rotary evaporator. The aqueous phase was washed twice with methylene chloride and acidified to pH 3-4 with 32.5 ml (130 mmol) of 4N hydrochloric acid. The suspension obtained was cooled and filtered. The filter residue was washed with a small amount of ice water and dried. There were obtained 36.67 g (99%) of (S)-7-fluoro-12,12a-dihydro-9-oxo-9H,11H-azeto[2,1-c]imidazo[1,5-a][1,4]benzodiazepine-1-carboxylic acid of m.p. 159°-160°.

Provenance & Evidence