4,5-dihydro-3-(1-hydroxypropyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one → 4,5-dihydro-5-methyl-3-propionyl-6H-imidazo[1,5-a][1,4]-benzodiazepin-6-one

Participants

Reaction Steps

A mixture of 1.84 g (6.8 mmol) of 4,5-dihydro-3-(1-hydroxypropyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one, 16 g of manganese dioxide and 150 ml of methylene chloride is stirred at room temperature under an argon atmosphere for 2 hours. The manganese dioxide is filtered off under suction over a glass filter and the filtrate is evaporated in vacuo. After recrystallisation of the residue from 100 ml of ethyl acetate, there is obtained 4,5-dihydro-5-methyl-3-propionyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one of melting point 215°-216° C.

Provenance & Evidence