7-chloro-4,5-dihydro-3-(hydroxymethyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one → 7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde

Participants

Reaction Steps

18.0 g (64.8 mmol) of 7-chloro-4,5-dihydro-3-hydroxymethyl-5methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one, 75 g of manganese dioxide and 700 ml of methylene chloride are stirred at room temperature for 1.5 hours. The reaction mixture is filtered and the filtrate is evaporated. By recrystallization of the residue from alcohol there is obtained 7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde of melting point 204°-205°.

Provenance & Evidence