GREEN CATALYTIC OXIDATION OF CYCLOHEXANONE TO ADIPIC ACID

Synthesis of adipic acid by Na 2WO 4·2H 2O catalyzed oxidation of cyclohexanol/cyclohexanone with 30 percent hydrogen peroxide oxidation in the presence of acid ligands can be well performed. The reaction takes place without any organic solvent and phase transfer agent. The effects of various ligands and the ratio of Na 2WO 4·2H 2O with ligand are investigated. By using sulfosalicylic acid as acidic ligand and the mole ratio of sulfosalicylic acid to Na 2WO 4·2H 2O is 1∶2, the isolated yield of adipic acid in the oxidation of cyclohexanone and cyclohexanol is 82.1% and 68.6%, respectively. Further experiment is carried out to investigate the catalytic activity of this catalyst system when catalyzing the oxidation reaction of the mixture of cyclohexanone and cyclohexanol to adipic acid.