Benzodiazepine derivatives and pharmaceutical compositions containing

Abstract

Novel 4H-pyrrolo[1,2-a][1,4]benzodiazepine derivatives of the formula ##STR1## wherein at least one of R.sub.1, R.sub.2 and R.sub.3 represent lower alkyl and the remainder hydrogen, R.sub.4 represents hydrogen or lower alkyl, ring A optionally contains at least one substituent selected from halogen, nitro and trifluoromethyl, and ring B optionally contains at least one substituent selected from halogen, nitro, trifluoromethyl, lower alkyl and lower alkoxy; and novel intermediates thereof expressed by the formula ##STR2## wherein Z represents protected amino. Compounds of formula (I) are prepared by subjecting compounds of formula (II) to protective group-elimination and cyclization. The compounds of formula (I) and acid addition salts thereof have useful anti-anxietic, sedative, anti-convulsant, muscle relaxant and hypnotic, and their toxicity is low.