复合催化剂—酸性阳离子交换树脂/乙醇催化合成5-对羟基苯基乙内酰脲

以复合催化剂酸性阳离子交换树脂/乙醇一步催化合成5-对羟基苯基乙内酰脲,考察了醇的种类及用量、盐酸浓度、反应物摩尔比、反应温度及反应时间对产品收率的影响。优化的合成工艺为:酸性阳离子交换树脂加入量为反应物总质量的10%,乙醇加入量为40~50 mL/mol乙醛酸,盐酸浓度0.6 mol/L,n(乙醛酸)∶n(苯酚)∶n(尿素)=1∶2∶(2~2.5),反应温度90℃,反应时间5~6 h,产品收率可达70%。

Synthesis of 5-(p-hydroxyphenyl)hydantoin using composite catalyst acidic cation-exchange resin/ethanol

5-(p-Hydroxyphenyl)hydantoin was synthesized using the composite catalyst acidic cation-exchange resin/ethanol.The effect of the amount of ethanol,the concentration of HCl,the molar ratio of reactants,reaction temperature and reaction time on the yield of product were researched.The optimal reaction conditions were as follows:the quantity of the resin is 10% of the total reactant quantity and the quantity of ethanol is 40～50 mL/mol glyoxylic acid,the concentration of HCl is 0.6 mol/L;n(glyoxylic acid) ∶n(phenol) ∶n(urea) is 1 ∶2 ∶(2～2.5) the reaction temperature is 90 ℃,the reaction time is 5～6 h,the yield of final product could reach 70%.