碱性离子液体催化合成碳酸甲乙酯

Synthesis of ethyl methyl carbonate catalyzed by basic ionic liquids

以碱性离子液体为催化剂,对碳酸二甲酯(DMC)和碳酸二乙酯(DEC)酯交换反应合成碳酸甲乙酯进行了研究.筛选出高催化活性的碱性离子液体1-丁基-3甲基咪唑丁酸盐([C4mim][CH3(CH2)2COO])为催化剂,详细考察了反应时间、温度、催化剂用量、原料配比等因素对酯交换反应的影响.实验结果表明,在反应温度为90℃,催化剂用量为6%(占反应物总质量百分数),n(DMC)∶n(DEC)=1.5∶1,反应时间为5h时,DEC的转化率高达48%.[C4mim][CH3(CH2)2COO]重复利用5次后仍保持较高的催化活性.

The synthesis of ethyl methyl carbonate （EMC） by transesterification of dimethyl carbonate （DMC） and diethyl carbonate （DEC） in the presence of alkaline ionic liquids as cata‐lysts was studied ,in which alkaline ionic liquid 1‐butyl‐3‐methylimidazolium butyrate （[C4 mim][CH3 （CH2 ）2 COO ]） was selected due to its good catalytic performance compared with other alkaline ionic liquids .The effects of reaction time ,temperature ,catalyst loading and mo‐lar ratio of reactants on the conversion of the DEC were examined .Under the suitable reaction conditions of reaction temperature 90 ℃ ,catalyst dosage 6% （based on the total mass of the re‐actants） ,n（DMC） ∶ n（DEC） = 1 .5 ∶ 1 ,reaction time 5 h ,the conversion of DEC was 48% . After alkaline ionic liquid [C4 mim ][CH3 （CH2 ）2 COO ] was recovered and reused five times without obvious loss of its catalytic activity .