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

Participants

Reaction Steps

6.73 g (27.6 mmol) of 4,5-dihydro-3-hydroxymethyl-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one was stirred at room temperature for 4 hours together with 33 g (380 mmol) of manganese dioxide in 100 ml of methylene chloride. The mixture was filtered, the filter residue was rinsed thoroughly with about 1.5 l of methylene chloride and the filtrate was evaporated. There was obtained 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3--carboxaldehyde of melting point 202°-203°.

Provenance & Evidence