室温离子液体介质中酯化反应的研究

Study on Esterification in Room Temperature Ionic Liquids

在多种1,3二烷基咪唑离子液体和适量三氯化铝构成的催化反应体系中,研究了丙酸和一系列醇的酯化反应.与浓硫酸作催化剂相比,离子液体四氟硼酸1甲基3丁基咪唑([BMIm]BF4)/三氯化铝催化体系具有更好的催化活性,可获得适中至高的酯化率与选择性,并且产物和离子液体催化体系不溶而分层,便于分离,离子液体可以稳定地循环使用5次以上.

Esterification of propanoic acid with alcohols in various ionic liquids 1, 3-dialkylimidazolium -aluminium（Ⅲ） chloride as the catalyst and reaction medium was investigated. Compared with concentrated sulfuric acid, ionic liquids 1-hutyl-3-methylimidazolium tetrafluorohorate （[BMIm] BF4 ）-aluminium （Ⅲ）chloride showed better catalytic activity. The results showed that esters with medium to high conversion and selectivity could be formed, and easily separated from ionic liquids due to their immiscibility. Ionic liquids-aluminium（Ⅲ） chloride could be reused, and the catalytic activity was not decreased obviously after 5 times recycle. This protocol has notable advantages of no need of organic solvents, mild conditions, simple operation, short reaction time, ease work-up, high yields and recycling of the ionic liquid.