超声波辐射对甲苯磺酸催化合成类辣椒素的工艺研究

STUDY ON SYNTHESIS OF CAPSAICINOID CATALYZED BY p-TOLUENE SULFONIC ACID UNDER ULTRASONIC RADIATION

在无水乙醇介质中,以邻苯二酚和N-羟甲基丙烯酰胺为原料,对甲苯磺酸为催化剂,超声波辐射下合成类辣椒素N-(3,4-二羟基-6-丙烯酰胺甲基苄基)丙烯酰胺。利用IR和1H NMR对产品的结构进行了表征,并考察了原料摩尔比、超声波辐射功率及时间、催化剂用量、反应温度等因素对产品收率的影响。实验结果表明,超声波辐射下,对甲苯磺酸对该反应具有良好的催化活性,最佳合成工艺条件为:邻苯二酚11.0 g(0.1 mol),n(邻苯二酚)∶n(N-羟甲基丙烯酰胺)=1∶2.4,对甲苯磺酸用量为邻苯二酚质量的4.09%,反应温度35℃,超声波辐射功率160 W,辐射反应时间为50 min。产物收率达到82%以上。

In anhydrous ethanol medium,using catechol and N-methylol acrylamide as raw materials,and p-toluenesulfonic acid as a catalyst,the capsaicinoid,N-(3,4-dihydroxy-6-acrylamide methyl benzyl)acrylamide,was synthesized under ultrasonic radiation.The molecular structure of the product was characterized by IR and 1H NMR.The effects of molar ratio of raw material,ultrasonic radiation power and time,amount of catalyst,and reaction temperature on the yield of the product were also investigated.The experimental results show that under ultrasonic radiation,p-toluenesulfonic acid has good catalytic activity for the reaction.The optimum synthesis conditions are as follows:catechol 11.0 g(0.1 mol),n(catechol)∶n(N-methylolacrylamide)=1∶2.4,the amount of p-toluenesulfonic acid is 4.09%of the mass of catechol,the reaction temperature is 35℃,the ultrasonic radiation power is 160 W,and the radiation reaction time is 50 min.The product yield reached more than 82%under these optimized reaction conditions.