壳聚糖硫酸盐催化合成尼泊金甲酯

以壳聚糖硫酸盐为催化剂合成了尼泊金甲酯。考察了壳聚糖脱乙酰度的影响因素及壳聚糖硫酸盐的催化活性。最佳酯化反应条件为:n(甲醇):n(对羟基苯甲酸)=4:1,壳聚糖硫酸盐用量为对羟基苯甲酸质量的0.93%,回流反应4 h,产物收率达93.1%。该催化剂用于合成尼泊金甲酯具有良好的催化活性和重复使用性。

SYNTHESIS OF METHYLNIPAGIN ESTER CATALYZED BY CHITOSAN SULFATE

Methyl nipagin ester was synthesized using chitosan sulfate as catalyst.The deacetylation degree of chitosan,reaction conditions of sulfuric acid alkylation,catalytic activity,dosage of catalyst, reaction time,and the ratio of alcohol to acid on the yield of methyl nipagin ester were carefully studied.Through orthogonally arranged experiments,the optimal conditions were obtained as follows: molar ratio of methanol to acid = 4 to 1,0.93% catalyst based on the mass of acid,reaction time under refluxing 4 h.Under these conditions,the yield of the esterification reached 93.1%.The results showed that chitosan sulfate had excellent catalytic activity and could be used repeatedly.