RESEARCH ON NITROGEN CONTAINING HETEROCYCLIC-COMPOUNDS .17. SYNTHESIS OF 8H-DIIMIDAZO[1,5-A-2',1'-C][1,4]BENZODIAZEPINE, A NOVEL TETRACYCLIC RING OF PHARMACEUTICAL INTEREST

The synthesis of 8H-diimidazo[1,5-a:2',1'-c][1,4]benzodiazepine 6, a novel nitrogen-containing tetracyclic ring, is reported starting from 5H-imidazo[2,1-c][1,4]benzodiazepine 7. Reaction of this compound with nitromethane and subsequent reduction of the obtained nitromethyl derivative 8 afforded 11-aminomethyl-10,11-dihydro-5H-imidazo[2,1-c][1,4]benzodiazepine 9. Treatment of the latter compound with formaldehyde led to 1,2,3,3a-tetrahydro-8H-diimidazo[1,5-a:2',1'-c][1,4]benzodiazepine 10, which was then oxidized to the title compound.