[Study of 1,5-benzodiazepines. II. Synthesis of 2,4-di-(N-alkyl,N-phenyl)amino-3H-1,5-benzodiazepine].

Following the procedure we described for synthesizing analogous compounds in Note I (7), reaction of N,N-dialkyl or (N-alkyl,N-phenyl)ethoxycarbonylacetamides with 4-chloro-1,2-phenylendiamine, in the presence of phosphorus oxychloride, afforded 2,3-dihydro-2-oxo-4-dialkyl (N-alkyl,N-phenyl)amino-chloro-1H-1,5-benzodiazepines. When a large amount of phosphorus oxychloride was employed in the reaction, the formation of 2,4-di-(N-alkyl,N-phenyl)amino-3H-1,5-benzodiazepines was achieved, starting from suitable o-phenylendiamines and (N-alkyl,N-phenyl)ethoxycarbonylacetamides. Pharmacological tests were carried out on some compounds described in the present paper and on others reported in the preceding Note (7); in this connection 4-amino-1,5-benzodiazepine derivatives showed weak CNS depressing activity in addition, in some cases, to clear, although moderate, anticonvulsant activity, whereas 2,4-diamino-1,5-benzodiazepine derivatives were practically without effect.