Regioselective synthesis of 2-(1H-benzimidazol-1-yl)-5-nitro- and 2-(5-nitro-1H-benzimidazol-1-yl)anilines

The efficiency of two strategies for the synthesis of N-(2-aminophenyl)-5-nitrobenzimidazole derivatives was studied. The promising route involves the stages of 1-(2,4-dinitro-phenyl)-1H-benzimidazole monoreduction at 2-positioned nitro group and tandem conversion involving recyclization of the intermediate N-(2-amino-4-nitrophenyl)-5-nitrobenz-imidazole.