硅胶固载离子液体[HSO3-Pmim]HSO4催化合成尼泊金乙酯

Ethyl p-hydroxybenzoate was synthesized with ionic liquids [HSO3-Pmim] HSO4 immobilized on silica gel as catalyst

采用硅胶固载离子液体[HSO3-Pmim] HSO4催化合成尼泊金乙酯.考察了反应温度、反应时间、酸醇摩尔比、固载化离子液体用量对产率的影响.结果表明：硅胶固载离子液体[HSO3-Pmim] HSO4对尼泊金乙酯的合成有较好的催化作用,当酸醇摩尔比1：3.5,反应温度95℃,回流反应3h,催化剂用量相对于酸的摩尔比为4％,其产率可达到92％以上.硅胶固载离子液体[HSO3-Pmim] HSO4催化剂在反应完毕后趁热过滤即可与尼泊金乙酯分离.催化剂重复使用5次,其催化活性下降不明显.

Ethyl p-hydroxybenzoate was catalytically synthesized with ionic liquids [HSO3-Pmim] HSO4 immobilized on silica gel.The effects of reaction temperature,reaction time,and molar ratio of acid to alcohol,immobilization of ionic liquid dosage on the yield was investigated.The results indicated that ethyl p-hydroxybenzoate was better synthesized with ionic liquids [HSO3-Pmim] HSO4 immobilized on catalyst silica gel,the mole ratio of acid to alcohol 1：3.5,reaction temperature 95℃,reflux reaction for 3h,the amount of catalyst with respect to acid ratio was 4％.Under the above situations,the yield can reach more than 92％.After the reaction,ionic liquids [HSO3-Pmim] HSO4 immobilized on silica gel can be separated from ethyl p-hydroxybenzoatethrough hot filtering.The catalyst was reused for 5 cycles with consistent catalytic activity.