无溶剂微波辐射固体碱催化酚的乙酰化反应

用浸渍法和微波辐射法制备Al2O3负载的固体碱催化剂,考察了负载型固体碱及相应无负载固体碱于无溶剂条件下对苯酚的乙酰化反应的催化作用。结果表明,微波辐射制备的K2CO3/Al2O3效果较好,在n(K2CO3/Al2O3)/n(苯酚)=0.168、60℃时,乙酸苯酯产率为93.5%。使用该催化剂在微波辐射下进行酚同系物的乙酰化反应,微波法的反应时间为9 min,乙酸酚酯产率为75.8%~100.0%,优于传统加热法(150 min,61.6%~98.4%)。

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%).