一种新型噻唑盐的微波辅助合成及对安息香缩合的催化作用

以4-甲基-5-羟乙基噻唑和对氰基氯化苄为原料微波合成一种新型噻唑盐,3-(对氰基苄基)-4-甲基-5-(2-羟乙基)噻唑氯化物,再用此噻唑盐替代VB1作为安息香缩合反应的催化剂,检验其催化性能,发现催化苯甲醛得苯偶姻收率为74.5％、催化糠醛得糠偶姻收率为76.1％,此噻唑盐不仅具有天然VB1的无毒性,且可回收利用;考察了物质的量投料比、反应时间、反应温度及微波反应器功率对此噻唑盐收率的影响;并用HPLC测定产物的纯度,通过熔点、元素分析、IR及LC-MS对噻唑盐性质和及苯偶姻结构进行了表征.

Microwave-aided synthesis of a novel thiazolium salt and its catalytic function for benzoin condensation

The 4-methyl-5-hydroxyethyl thiazole and p-cyanobenzyl cloride were taken as raw materials to synthesize a novel thiazolium salt of 3-(p-cyanobenzyl)-4-methyl-5-(2-hydroxyethyl)-1, 3-thiazolium chloride with microwave technique and then the VB1 was substituted by this thiazolium salt as catalyst of benzoin condensation reaction. Its catalytic performance was checked and it was found that when it was used to catalyze benzaldehyde, the benzoin would be obtained, with yield-rate of 74.5%; when it was used to catalyze furaldehyde, the furoin would be obtained, having yield-rate of 76.1%. This thiazolium salt would be not only without toxicity but also could be recovered and reused. The influence of a mount of substance putting ratio, reaction duration, reaction temperature, and power of microwave reactor on the yield-rate of this thiazolium salt was investigated. The purity of the resultant was determined with HPLC and the property of thiazolium salt and structure of benzoin were characterized by means of analysis of element composition and melting-point, IR, and LC-MS.