5-aminobenzimidazolone was prepared by electro-reduction of 5-nitrobenzimidazolone on copper mesh cathode. The electrochemical behavior was studied on Cu micro-electrode by cyclic voltammetry

and the result indicated that the electrochemical reduction of 5-nitrobenzimidazolone was an irreversible reaction controlled by diffusion. Influence of some key factors (such as nature of cathode material

current density

temperature and passed charge) on this reaction was investigated. Under the optimized condition

the yield of 5-aminobenzimidazolone reached 93%. The yield of 5-aminobenzimidazolone could still be maintained at about 93% after the catholyte was continuously recycled 10 times

corresponding to the effect of fresh catholyte.