Hydrochloric Acid → (S)-8-chloro-11,12,13,13a-tetrahydro-1-(hydroxymethy)-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepin-9-one

Participants

Reaction Steps

A suspension of 81.2 g (234.8 mmol) of ethyl (S)-8-chloro-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate in 450 ml of dry tetrahydrofuran is heated to about 50° and a suspension of 6.1 g (279 mmol) of lithium borohydride in 60 ml of tetrahydrofuran is added dropwise to the solution obtained. The suspension is subsequently heated to boiling under reflux for 3 hour. The mixture is cooled to room temperature and there are added dropwise thereto firstly 40 ml of 3N hydrochloric acid and then 260 ml of a solution consisting of 130 ml of conc. hydrochloric acid and 130 ml of water. The solution obtained is stirred at 40° for 15 minutes, the tetrahydrofuran is distilled off in vacuo and the aqueous residue is made alkaline with 25 percent ammonia. The precipitated material is then filtered off under suction, washed with water and dried at 80° in high vacuum. There is obtained (S)-8-chloro-11,12,13,13a-tetrahydro-1-(hydroxymethy)-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepin-9-one of melting point 303°-305° .

Provenance & Evidence