Carbon tetrabromide → HCID 19851581, compound

Participants

Reaction Steps

3.0 g (10.9 mmol) of 7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde and 5.7 g (21.7 mmol) of triphenylphosphine were dissolved in 80 ml of methylene chloride at room temperature. Thereafter, the mixture was cooled with an ice-bath to 0° and at this temperature there was added dropwise thereto a solution of 4.0 g (12.0 mmol) of tetrabromomethane in 15 ml of methylene chloride. Thereafter, the mixture was stirred at room temperature for a further 6 hours and subsequently evaporated in a vacuum. The residue was suspended in ethyl acetate and heated under reflux for 30 minutes, cooled to 10° while stirring, suction filtered and dried. The crystalline crude product was recrystallized from alcohol and there was obtained 7-chloro-3-(2,2-dibromovinyl)-4,5-dihydro-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one hydrobromide as white crystals of melting point 215°-217°.

Provenance & Evidence