1,4-benzodiazepin of the formula ##STR1## wherein R is a low molecular straight or branched alkyl and X is halogen or trifluoromethyl, and pharmaceutically acceptable acid addition salts of these benzodiazepins. The benzodiazepins are made by heating an acyldiamine in the presence of phosphorus oxychloride at the latter's boiling point followed by reacting the resulting mixture of 7-member and 8-member compounds with an alkali metal alkoxide.