Acetylation of Phenols Catalyzed by Solid Bases in Solvent-free Condition Under Microwave Irradiation

Al2O3 supported solid base catalysts were prepared by the microwave impregnation and the traditional impregnation.The catalytic effects on the acylation of phenol with acetic anhydride were investigated over the catalysts prepared by the microwave impregnation and the traditional impregnating,and these of the non-supported solid bases.Of theses catalysts the microwave impregnating one K2CO3/Al2O3 was good.The yield of phenyl acetate was 93.5% at 0.168 mol ratio of catalyst/phenol,60 ℃.The acetylation of phenol analogs that catalyzed by this catalyst under the microwave irradiation,the reaction time using the microwave heating was much shorter than the traditional method(for 9 min vs 150 min) with the yields of substituted phenyl acetate increased slightly(75.8%～100.0% vs 61.6%～98.4%).