Direct Oxidation of Cyclohexene to Adipic Acid Catalyzed by WO_3

In the absence of organic solvent,acidic ligand and phase-transfer catalyst,synthesis of adipic acid by WO3 catalyzed oxidation cyclohexene with 30 percent hydrogen peroxide can be performed with higher yields and purities.Under the condition of 5 mmol WO3,1:40:176 mole ratio of WO3:C6H10:H2O2, refluxing temperature and 6 h reaciton time,the isolated yield of adipic acid reaches 75.4% and it purity is 99.8%. WO3 catalyst can be reused for 4 times and the isolated yield of adipic acid is still above 70%.The results of FTIR and XRD analysis show that the structure of the recycling WO3 catatlys is stable.