酸性离子液体催化对羟基苯甲酸丁酯合成的工艺条件

Synthesis of Butyl p-Hydroxybenzoate Catalyzed by Acidic Ionic Liquid

以自制合成的酸性离子液体[HSO3-p Py]HSO4为催化剂,用于催化对羟基苯甲酸和正丁醇酯化反应合成的对羟基苯甲酸丁酯,以对羟基苯甲酸丁酯收率为评价指标,探究合成工艺参数(反应物摩尔比n(正丁醇)︰n(对羟基苯甲酸)、催化剂[HSO3-p Py]HSO4的用量、反应温度和时间)对对羟基苯甲酸丁酯合成反应的影响。研究表明,离子液体[HSO3-p Py]HSO4对对羟基苯甲酸丁酯合成反应有很好的催化作用,在n(正丁醇)︰n(对羟基苯甲酸)为4︰1,催化剂[HSO3-p Py]HSO4的用量为5%,反应温度为120℃,反应时间为3.5 h时,对羟基苯甲酸丁酯收率最高(94.3%),并且催化剂[HSO3-p Py]HSO4连续使用6次后,对羟基苯甲酸丁酯收率无明显降低。

Acidic ionic liquids[HSO3-p Py]HSO4 was synthesized by a two-step methods,and butyl p-hydroxybenzoate was synthesized by esterification of p-hydroxybenzoic acid and n-butyl alcohol with[HSO3-p Py]HSO4 as catalyst.To explore the synthesis process parameters of n(n-butanol)︰n(p-hydroxybenzoic),the effects of the amount of catalyst[HSO3-p Py]HSO4,reaction temperature and reaction time on the yield of butyl p-hydroxybenzoate were tested.The research showed that ionic liquids[HSO3-p Py]HSO4 had good catalytic activity on the synthesis of butyl p-hydroxybenzoate,the optimum reaction conditions were n(n-butanol)︰n(p-hydroxybenzoic)=4︰1,the amount of catalyst[HSO3-pPy]HSO4=5%,T=120℃and t=3.5 h,and the yield of butyl p-hydroxybenzoate could reach 94.3%.After the catalyst was used for 6 times,the yield of butyl phydroxybenzoate was not significantly reduced.