Tetrahydrofuran → 7-chloro-4,5-dihydro-5-methyl-3-vinyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one

Participants

Reaction Steps

6.25 g of an equimolar mixture of methyltriphenylphosphonium bromide and sodium amide was stirred for 15 minutes in 40 ml of tetrahydrofuran. 4.13 g (15 mmol) of 7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde was then added to the yellow suspension, whereby the temperature rose to 43° and the suspension decolorized. The mixture was stirred for a further 1 hour, filtered and the filtrate was evaporated. After chromatography of the residue on silica gel while eluting with cyclohexane/ether/isopropanol (3:3:1) and recrystallization from ethyl acetate there was obtained 7-chloro-4,5-dihydro-5-methyl-3-vinyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one of melting point 205°-207°.

Provenance & Evidence