Br?nsted酸性离子液体的合成及催化酯化反应的应用

摘要

以苄基氯、N-乙基咪唑、浓硫酸为原料,合成了一种含有磺酸基的新型Brönsted酸性离子液体,通过IR、1H NMR对其结构进行了表征。将其应用于催化乙酸和乙醇的酯化反应,考察了其反应条件和循环使用性能。结果表明最佳反应条件为:反应时间90 min,催化剂用量5%,反应温度80℃。此条件下产率为72.35%。离子液体循环使用4次,其催化效率基本不变。A novel Brönsted acid ionic liquid was synthesized using benzyl chloride, N-diethyl imidazole and sulfuric acid as materials. Its structure was confirmed through IR and 1H NMR. The catalytic activity of the acidic ionic liquids for the esterification of acetic acid with ethanol was measured. Ethyl acetate with a yield of 72.35% was obtained under the following conditions: molar percentage of catalyst relative to the reactants 5%, reaction temperature 80°C and reac-tion time 90 min. The ionic liquid can be reused for more than four times without remarkable loss of catalytic activity.