固体碱催化苯乙酮和碳酸二甲酯合成苯甲酸甲酯

Synthesis of Methyl Benzoate from Acetophenone and Dimethyl Carbonate over Solid Base

以固体酸碱为催化剂,研究了碳酸二甲酯与苯乙酮合成苯甲酸甲酯的反应,考察了反应温度、反应时间、催化剂用量和原料摩尔配比等因素对反应结果的影响。实验结果表明,固体酸催化剂不利于苯甲酸甲酯的生成,而具有中强碱位的MgO对反应有较好的催化活性。当以MgO为催化剂,在反应温度为260℃,反应时间5 h,催化剂用量为反应物总质量的1.5%,n(苯乙酮)∶n(DMC)=1∶4的条件下,苯乙酮的转化率和苯甲酸甲酯的选择性分别达72.0%和59.8%。另外,反应的副产物主要为乙酸甲酯、少量苯乙酮缩合的产物、甲基化及醚化产物等。

The synthesis of methyl benzoate was carried out from acetophenone and dimethyl carbonate （DMC） in the presence of solid acid and base catalysts. The results showed that solid acid catalyst such as Al2O3 and Hβ are inactive towards the synthesis of methyl benzoate. As for the solid base catalysts,MgO, which possessed moderate basic strength, exhibited high catalytic activity. Under the optimal reaction conditions ： temperature 260 ℃, time 5 h, w （catalyst） = 1.5 % and n （acetophenone） ：n（DMC） = 1：4 ,the conversion of acetophenone and the selectivity to methyl benzoate reached 72.0% and 59.8% respectively. The main by-products of the reaction is methyl acetate. The self-condensation products of acetophenone （ 1,3-diphenyl-2-buten-l-one ）, methylated product （ propiophenone ） and etherification product（1-methoxyethenylbenzene） were also detected.