HCID 20524940, compound → HCID 21469979, compound

Participants

Reaction Steps

The process described in U.S. Pat. No. 4,280,957 comprises decarboxylating the corresponding imidazo-benzodiazepine-carboxylic acid at 100°-350° C., optionally in the presence of a solvent and a catalyst. This process has the disadvantage that in addition to the desired 4H-imidazo[1,5-a][1,4]-benzodiazepine derivative of formula I there is obtained a considerable amount of the corresponding isomeric 6H-imidazo[1,5-a][1,4]-benzodiazepine derivative, which requires an expensive re-isomerization.

Provenance & Evidence