Green Synthesis of Adipic Acid by Oxidation of Cyclohexanone with Hydrogen Peroxide

Adipic acid was synthesized by tungstenic acid/phosophoric acid ligand catalyzing oxidation cyclohexanone with 30 percent hydrogen peroxide in the absence of organic solvent and phase-transfer catalyst. The main effects of the reaction were optimized with orthogonal experiments and simple fact experiments . The results showed that under the optimal condition, i.e., the mole ratio of C6H10O∶H2O2∶H2WO4∶H3PO4 was 100∶500∶2.5∶2.5, the reaction temperature was 90℃ and the reaction time was 5h,the isolated yield of adipic acid could reach 86.7%. If the tungstic acid alone was used as catalyst, the isolated yield of adipic acid was only 69.4 % .