酸性离子液体的合成及催化缩醛反应的应用

Abstract

使用苄基氯，N-乙基咪唑，吡啶等合成了3种新型的离子液体，对其结构进行了表征，并将其应用于催化合成苯甲醛缩醛反应，通过与传统催化剂催化效果相对比，最终确认N-乙基咪唑-N(对磺酸基)苄基-氯化咪唑盐离子液体有良好的催化性能，其催化效率比传统的硫酸铜催化剂高，并进一步对该离子液体的催化条件进行了优化，结果表明，离子液体用量为原料总物质的量的2.8%，反应时间2 h，反应温度125℃时，催化效果最好，产率达到了88.59%，离子液体重复使用4次，催化效能未见明显下降。 Three novel ionic liquids were synthesized using benzyl chloride, N-ethyl imidazole and pyridine as raw materials, the structure of these products were charactered, and these materials were applied to catalytic synthesis of benzaldehyde acetal. Compared with the traditional catalyst, the N-ethyl imidazole-N (p-sulfo) benzalhydantoin-chloride imidazole salt ionic liquids have good catalytic activity. The synthesis reaction of benzaldehyde acetal catalyzed by the acidic ionic liquid was studied. The result shows that the yield of benzaldehyde acetal was 88.59% under the following conditions: Molar percentage of catalyst relative to the reactants 2.8%, reaction temperature 125˚C and reaction time 2 h. The catalytic activity maintains stable even the acidic ionic liquid was used 4 times.