Synthesis and biological activity of certain pyridobenzodiazepine derivatives

The present work comprises the synthesis of 6,11-dihydro-5H-pyrido [2,3-b] [1,5] benzodiazepine-5-one derivatives 5-7 by condensation of 2-chloro-4,6-dimethylnicotinic acid [1] with 1,2-phenylenediamines 2-4 using t-butoxyethanol as solvent. Monoalkylation of 5-7 using one equivalent of the appropriate alkyl halide and 30% NaOH in dimethylsulfoxide gave the 6-alkyl derivatives 8-19. Some of the prepared compounds were preliminary screened for CNS depressant and anticonvulsant activities