L-脯氨酸离子液催化苹果酯的合成

Studies on catalytic synthesis of fructone by L-proline ionic liquid

以L-脯氨酸离子液为催化剂,对乙酰乙酸乙酯和乙二醇合成苹果酯的催化工艺进行了系统研究.考察了酯醇比、催化剂用量、反应时间、带水剂种类和用量及催化剂重复使用等因素对酯化率的影响.结果表明,n(乙酰乙酸乙酯)∶n(乙二醇)=1.0∶1.4,催化剂用量为2.0 g/mol乙酰乙酸乙酯,带水剂环己烷为40 mL,110℃下反应3.5 h,苹果酯收率达到88.9%.反应结束后,通过简单的萃取操作,可使催化剂回收和重复使用.循环使用4次,催化剂的催化活性无明显改变.

The synthesis of fructone from ethyl acetoacetate and ethylene glycol using L-proline ionic liquid as catalyst was investigated.Various reaction parameters such as ratio of ethyl acetoacetate to ethylene glycol,catalyst amount,the catalyst dosage,the effects of the sort of water-carrying agent and the water-carrying reagent amount,reaction time,et al on the yield were investigated in details.The experimental results indicated that the molar ratio of ethyl acetoacetate to ethylene glycol was 1.0∶1.4,the quantity of catalyst was equal to 2.0 g/mol ethyl acetoacetate,amount of cyclohexane was 40 mL,and the reaction time was 3.5 h.The yield of fructone reached 88.9 % under the optimum condition.The isolation of the desired products could be achieved via simple separation and ionic liquids could be reused.The catalytic activity was not decreased obviously after 4 times recycle.