SO^(2-)_4 改性交联蒙脱土固体酸催化合成水杨酸正丁酯

Synthesis of n-Butyl Salicylate Catalyzed by SO^(2-)_4 Modified Cross-linked Montmorillonite Solid Acid

制备了SO2-4改性硅锆双组分交联蒙脱土固体酸催化剂(SO2-4/SiZrM),用于水杨酸(C7H6O3)和正丁醇(C4H10O)的酯化反应,与传统酯化反应催化剂浓硫酸、磷钨酸、硫酸铁铵以及其他单组分交联剂交联的蒙脱土做酯化反应的催化剂相比,SO2-4/SiZrM有更好的催化活性。考察了带水剂的选择、酸醇量比〔n(C7H6O3)∶n(C4H10O)〕、催化剂用量〔w(SO2-4/SiZrM)〕、反应时间(t)、反应温度(θ)对催化合成水杨酸正丁酯(C11H14O3)的影响,并对合成的产物进行了折光率、红外光谱分析。酯化反应的最佳条件为:C4H10O为带水剂、n(C7H6O3)∶n(C4H10O)=1∶1 65、催化剂占酸投料质量的百分比为w(SO2-4/SiZrM)=6 5%、t=6h、θ=120～135℃,水杨酸的转化率可达88 22%,产物中w(C11H14O3)>99 9%。

The mixed SiZr pillared montmorillonite,modified by SO2-4,was used as solid acid catalyst (SO2-4/SiZrM) in the esterification reaction of salicylic acid (C7H6O3) and nbutyl alcohol (C4H10O).The results showed that SO2-4/SiZrM exhibited higher activity in the synthesis of nbutyl salicylate (C11H14O3) than the traditional catalysts,such as concentrated sulfuric acid,phosphotungstic acid,ferric ammonium sulfate and other sorts of pillared montmorillonite.In the presence of SO2-4/SiZrM,the optimized reaction conditions for preparing C11H14O3 were as follows.Excess of nbutyl alcohol acted as water entrainer,n(C7H6O3)∶n(C4H10O)=1∶165,w(SO2-4/SiZrM) was 65% the weight of salicylic acid,reaction time was 6 h,and reaction temperature was 120-135 ℃.Conversion of salicylic acid amounted to 8822% and w(C11H14O3) was over 999% tested by GC analysis.