2-Acylaminomethyl-1,4-benzodiazepine derivatives and their salts, pharmaceutical compositions thereof and process for their preparation

Novel 2-acylaminomethyl-1H-2,3-dihydro-1,4-benzodiazepine derivatives are disclosed which possess the Formula I (I) wherein R1 represents hydrogen, lower alkyl, lower alkenyl or cyclopropylmethyl; R2 represents hydrogen, lower alkyl or lower alkenyl; R3 represents a group of the formula a, b, c or d; wherein R is hydrogen or C1-C3-alkyl; R4 is hydrogen, lower alkyl, lower alkoxy, nitro or halogen, and R4' is hydrogen or C1-C4-alkyl and the aromatic groups A and B may be unsubstituted or substituted by 1 to 3 substituents such as halogen, lower alkylthio, lower alkoxy, lower alkyl, hydroxy, nitro, trifluoromethyl or methylenedioxy or ethylenedioxy and optical isomers and acid addition salts of the compounds. In addition to psycho pharmacological, diuretic and antiarrhythmic properties, the novel compounds of Formula I possess primarily outstanding analgesic activities and are low in toxicity. The compounds are prepared by acylating 2-aminomethyl-1,4-benzodiazepine derivatives with corresponding carbonic acid derivatives. Furthermore, 2-azidomethyl-1,4-benzodiazepine derivatives are disclosed which provide valuable intermediates for the preparation of the compounds of Formula I yet also possess themselves pharmacological activities.