Synthesis of benzoic acid by catalytic oxidation of benzyl chloride in the presence of phase transfer catalyst

The synthesis of benzoic acid from benzyl chloride by KMnO_4 oxidation in the presence of phase transfer catalyst, quaternary ammonium salt CTAB is reported. The effects of CTAB amount, KMnO_4 amount, reaction temperature and time on the yield of benzoic acid are investigated. The results showed that the optimal reaction conditions were as follows: the molar ratio of potassium permanganate to benzyl chloride was 2∶1, the molecular fraction of CTAB was 8% of benzyl chloride, the reaction at 90℃ for 3 h,the yield of benzoic acid was 89%.