Benzimidazoles(3a-c,5a-c) were synthesized in a one step reductive cyclization reaction of(o-nitroanilines)(1,4) and aryl aldehydes(2a-c).

• 邻硝基苯胺(1；4)与芳香醛(2a-c)在连二亚硫酸钠存在下共热；发生还原关环反应；一步即可合成苯并咪唑类化合物(3a-c；5a-c).