Thirteen benzimidazole derivatives were synthesized in yields of 83%～98% by a one-step reaction of 1,2-phenylenediamine or 4-methyl-1,2-phenylenediamine with a series of aromatic aldehydes under the assistance of iodobenzene diacetate within the reaction time of 3～5 min. The structures of products were characterized by 1H NMR and IR, MS techniques and elemental analysis. The synthetic method has such advantages as the broad scope of reactants, mild reaction conditions, fast reaction velocity, and reasonably good yields. In addition, the possible mechanism of the reaction was proposed．

Key words: iodobenzene diacetate, 1,2-phenylenediamine, aromatic aldehyde, benzimidazole derivative