微波协同离子液体催化合成柠檬酸三丁酯

Microwave assisted synthesis of tributyl citrate by ionic liquids

酯化反应是重要有机合成反应之一,广泛应用于药物、材料、食品和香料等生产中。传统方法合成酯类具有反应时间长、产率低、污染大、副反应多及后处理困难等缺点;微波-离子液体合成法融合微波及离子液体两者优势,具有快速、高效、选择性好、产物易分离和对环境友好等特点。采用离子液体1-丁基-3-甲基咪唑硫酸氢盐作为催化剂,通过微波反应技术合成柠檬酸三丁酯。考察了反应物料醇酸比、催化剂用量、反应时间对反应最终转化率的影响,并通过正交实验对微波合成的工艺条件进行优化设计,得出离子液体催化下微波合成的最佳条件为:催化剂用量15%,反应物料醇酸比6.2∶1,微波反应时间4h,反应温度118℃,微波功率600W,转化率为71.78%。

Esterification is one of the most important organic reactions and widely used in medicine, material, food and perfume etc. The traditional synthesis process of esters have the disadvantages such as long reaction time, low yield, serious pollution, side reaction and difficult separation. Microwave assisted synthesis of esters catalysized by ionic liquids have the advantages such as less time, efficiency, convenient separation and safety. The ionic liquid 1-butyl-3-methylimidazolium hydrogen was used as the catalytic to synthesize tributyl citrate. The process conditions of catalytic esterification of TBC were studied by microwave reaction technology. The effects of alkyd ratio, amount of catalyst and reaction time on the final conversion of reaction were investigated. The process conditions of microwave synthesis of TBC were optimized by orthogonal design, and microwave synthesis under the catalysis of ionic liquid was obtained. The optimum conditions are as follows: the amount of catalyst is 15%, the reaction material alkyd ratio is 6.2∶1, the microwave reaction time is 4 h, the reaction temperature is 118℃, the microwave power is 600 W, and the conversion rate is 71.78%. The results of orthogonal analysis showed that the catalyst dosage had the greatest influence on the conversion rate and the reaction time was the second, and the influence of the alkyd ratio of the reaction material was relatively small. Compared with conventional heating and microwave radiation, the results show that microwave irradiation can effectively shorten the reaction time and reduce the reaction time from 7 h to 4 h. The reaction product was confirmed by Fourier transform infrared spectroscopy (FTIR), which confirmed that the target product was three butyl citrate. Viscosity analysis and other tests, all data are up to the standard.