Study on clean catalytic oxidation of cyclohexene to adipic acid

In conditions of no phase transfer catalyst and organic solvent,adipic acid was catalyzed by the prepared tungstic acid with hydrogen peroxide as an oxidant.The adipic acid systhesis conditions were optimized by single factor experiment.n(tungstic acid)=2.5 mmol,n(H2O2)∶n(cyclohexene)=4.9∶1,backflow reaction time was 6 h,25 mL 30% H2O2 and 10 mL cyclohexene were added.After 1 h of reaction,25 mL 30% H2O2 was added.The yield of adipic was up to 74.2%.The filtrate containing tungstic acid was concentrated and reused.The experimental results showed that the isolated yield of adipic acid had no marked decrease when the catalyst was reused 6 times.