[1,5-Benzodiazepines. III. Synthesis of 2,4-bisdialkylamino-3H-1,5-benzodiazepines].

Treatment of 2,3-dihydro-2-oxo-4-dialkylamino-1H-1,5-benzodiazepines with phosphorus pentasulfide afforded 2-thio derivatives which in turn gave the corresponding methylmercapto derivatives by reaction with sodium hydride and methyl iodide. By treating these compounds with dialkylamines the formation of 2,4-bisdialkylamino-3H-1,5-benzodiazepines was achieved. Pharmacological screening of some of the products indicated that the introduction of a second dialkylamino substituent into the 1,5-benzodiazepine molecule gave the compounds CNS excitant properties, while the initial monodialkylamino derivatives containing sulfur showed a CNS depressant activity.