A new "green" route to the synthesis of adipic acid

In this paper, a new "green" route to the synthesis of adipic acid is repor ted. This environmentally benign synthesis of adipic acid involves in the d irect oxidation of cyclohexene catalyzed by Na2WO4. 2H(2)O with 27.5% aqueo us hydrogen peroxide using alkyl ammonium sulfate as a phase transfer agent . The results show that N,N-dimethyl-dodecylammonium sulfate, dodecylammoni um sulfate and tri-n-octylammonium sulfate can be used as efficient phase t ransfer agents for this reaction under refluxing temperature. After the rea ction is stopped, the homogeneous solution was cooled to 0 degrees C for 12 h, Then the crystalline product was collected by filtration and dried in a ir, a colorless, analytically pure product adipic acid was obtained in 52.1 %-94.1% yields. The catalyst in concentrated filtrate can be reused.