Studies in the formation of heterocyclic rings containing nitrogen. Part VII. Condensation of 4-nitro-o-phenylenediamine with aromatic aldehydes

Abstract

On condensation with aromatic aldehydes 4-nitro-o-phenylenediamine has been found to yield mono and disubstituted benziminazoles, as well as mono or dianils in a few cases. The formation of monosubstituted benziminazoles or monoanils in greater proportion in these condensations than in those with methyl and chloro diamines may be attributed to the predominating influence of the nitro group of the diamine. The results provide strong support to the step-wise mechanism for the formation of benziminazoles through the intermediate anils.