Oxidation of Cyclohexanone to Adipic Acid Catalyzed by Heteropoly Complex with Dawson Structure

A Dawson structure heteropoly complex K10Na2H2P2 W16O60. 18H2O was prepared and used to catalyze the synthesis of adipic acid from cyclohexanone, oxidized by 30% hydrogen peroxide without any solvent or phase transfer agent. The results show that the catalyst had a high activity. The influences of reaction conditions such as ligands, amount of catalyst, ratio of reactants, reaction time were studied. Optimal reaction conditions were that n( tungsten): n( sulfosalicylic acid) : n( cyclohexanone) : n( hydrogen peroxide) was 2:1:100:400, and reflux temperature 98 ℃ , the time 5 h. The isolated yield of adipic acid could reach 76.7%.