苯甲醛安息香缩合反应催化合成苯偶姻新方法

制备了不同取代基的噻唑盐催化剂，研究了噻唑盐催化苯甲醛合成苯偶姻的安息香缩合反应，考察了噻唑盐取代基、催化剂用量、反应温度及反应时间对苯甲醛安息香缩合反应的影响规律。结果表明，以3-乙基-4-甲基-5-羟乙基噻唑溴盐为催化剂，噻唑盐用量为1．5％（以苯甲醛计，n／n，在反应温度为100％，反应时间为6h时，苯偶姻收率达72．5％，且反应过程中不需添加任何有机溶剂，具有环境友好的特点。

A Novel Synthesis of Benzoin Catalyzed by Thiazolium Salts

A novel method for synthesis of benzoin was achieved by the condensation of benzaldehyde in the presence of various thiazolium salts as the catalysts. The effects of various substituted groups bearing on the thiazolium salts, the different amount of catalyst, the reaction temperature and the reaction time on the benzoin condensation of benzaldehyde were investigated. Results showed 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide be the best catalyst. Benzoin could be obtained in 72.5% yield when the molar ratio of thiazolium salt to benzaldehyde was 1.5% and the reaction was performed at 100℃ for 6 h. Furthermore, the benzoin condensation was environment-friendly, without use of any volatile organic solvent.