Brφnsted酸性离子液体催化合成尼泊金酯

Synthesis of nipagin esters catalyzed by brφnsted acidic ionic liquid

以Brφnsted酸性离子液体[Hmim]Cl为催化剂催化合成尼泊金酯,考察了反应时间、醇酸摩尔比、离子液体用量等条件对反应的影响,确定了反应的最佳条件:对羟基苯甲酸的用量为0.04mol,反应时间2.5h,醇酸摩尔比为2∶1,离子液体用量为3mL,产率超过82%。离子液体可循环使用5次,催化活性基本不变。

Nipagin esters were synthesized with Brφnsted acidic ionic liquid [Hmin]Clas catalyst. The effects of reaction time, the molar ratio of alco- hol to acid and the concentration of ionic liquid on the yield of nipagin esters were investigated and the optimal condition were as follows： concentra- tion ofp-hydroxyhenzoic acid 0.04 mol, reaction time 2.5 h, the molar ratio of alcohol to acid 2：1, the concentration of ionic liquid 3 ml. Under these conditions, the yield of nipagin ester was over 82 %, and the ionic liquid could be used for 5 times repeatedly without any change of its catalytic efficiency.