o-Nitroaniline derivatives. Part VI. Cyanide-induced cyclisation of o-nitroanils

Abstract

Schiff bases derived from o-nitroaniline generally react with cyanide ion, in methanolic solution, to give 2-aryl-1-hydroxybenzimidazoles in moderate to good yield; N-p-nitrobenzylidene-o-nitroaniline gives N-p-nitrobenzoyl-o-nitroaniline as well as the benzimidazole derivative. N-o-Nitrobenzylidene-o-nitroaniline and its simple analogues, however, react with methanolic cyanide to give 3-methoxy-4-(o-nitroarylamino)cinnoline 1-oxides and methyl N-(o-nitroaryl)-o-nitrobenzimidates as the only isolated products.