新型酸性离子液体[Hmim]HSO_4中合成乙酸酯

Synthesis of Alkyl Acetate in Acidic Ionic Liquid [Hmim] HSO_4

制备了一种新型B rφnsted酸性离子液体[Hm im]HSO4,用于乙酸与醇的酯化反应,通过简单的相分离就可以实现产物乙酸酯与离子液体的分离。考察了温度、时间、物料配比、离子液体用量等因素对乙酸与正丁醇的反应的影响,得出反应的最佳条件为:反应温度110℃,反应时间2 h,酸醇摩尔比为2,酸性离子液体[Hm im]HSO4与醇的体积比为1,乙酸正丁酯的产率为97%。离子液体重复使用5次,乙酸正丁酯的产率均大于94%。利用核磁共振、红外和元素分析测试技术对酸性离子液体[Hm im]HSO4的结构进行了表征,是以一水合物的形式存在。测定了不同浓度[Hm im]HSO4水溶液的酸强度数据,结果表明,其酸性明显高于酸性离子液体[Hm im]CF3COO的酸性。

A novel acidic ionic esterification of acetic acid and liquid, [ Hmim]HSO4, was prepared and used as solvent and catalyst in the alcohols. The esterification products could be easily separated in high yield from the reaction system via simple phase separation. The acidic ionic liquid phase after removal of water could be reused. The effect of reaction conditions on product yield for the esterification between acetic acid and n-Butanol was studied. Butyl acetate with a yield of 97% was obtained under optimal conditions. The acidic ionic liquid [ Hmim]HSO4 was recycled 5 times and the yield of butyl acetate did not decrease remarkably. The structure of the acidic ionic liquid [ Hmim] HSO4 was characterized by ^1H NMR, IR, and elemental analysis, and it was found that [ Hmim] HSO4 existed as monohydrate. Acidity determination of aquoes solutions of [ Hmim] HSO4 showed that [ Hmim] HSO4 possessed stronger acidity than [ Hmim] CF3COO.