Brønsted-Lewis双酸性离子液体催化合成乙酸正丁酯

Syntheses of Brønsted-Lewis Acidic Ionic Liquids and the Catalytic Perfor-mance of N-butyl acetate

摘要:

以3-氨基丙磺酸、氯化锌、盐酸为原料制备了一系列Brønsted-Lewis双酸性离子液体。离子液体中阳离子磺酸基提供Brønsted酸性，阴离子提供Lewis酸性。采用FTIR、1HNMR、13CNMR、EA对合成的离子液体进行了结构表征；对离子液体的Brønsted酸性、Lewis酸性、腐蚀性进行了测定。使用该离子液体催化合成了乙酸正丁酯并利用响应曲面法考察了最佳反应条件。结果表明：反应温度103℃，催化剂[NH3C3H6SO3H]Cl/0.75ZnCl2（3-氨基丙磺酸盐酸盐与氯化锌物质的量比为1.00∶0.75）用量为正丁醇质量的10.03%，酸醇物质的量比为1.00∶1.22，反应时间4.92h，带水剂环己烷用量为正丁醇质量的20%条件下，乙酸正丁酯收率可达97.28%。[NH3C3H6SO3H]Cl/0.75ZnCl2重复使用5次后，催化剂活性没有明显降低。

Abstract:

A series of Brønsted-Lewis acidic ionic liquids were synthesized by homotaurine, ZnCl2 and HCl as the raw meterial. The cation of the ionic liquids can provide Brønsted acid and the anion can provide Lewis acid. The ionic liquids were characterized by FTIR, 1HNMR, 13CNMR and EA. The Brønsted acidity, Lewis acidity and corrosiveness of the ionic liquids were tested. The ionic liquids were used as the catalysts synthesizing n-butyl acetate and the optimal conditions was explored by response surface method. The results showed that the temperature is 103℃, the amounts of the catalyst is 10.03% of the mass of n-butanol, n(acetic acid)∶n(n-butanol)=1∶1.22, the reaction time is 4.92h, the amounts of cyclohexane is 20% of the mass of n-butanol, the yield can reach 97.28%. Furthermore, [NH3C3H6SO3H]Cl/0.75ZnCl2 was reused for 5 times, and it still had high catalytic activity.