高纯度蔗糖八乙酸酯的制备研究

文章将蔗糖八乙酸酯的合成和分离提纯相结合,阐明了制备高纯度SOA的途径.采用无水吡啶为催化剂能够有效提高SOA的产率及粗产物的纯度,并讨论了反应条件对合成的影响,得出最佳反应条件为:蔗糖、乙酸酐、催化剂的摩尔比为1∶11∶0.8,保温时间120 min,反应温度130～135℃.采用醇-水重结晶的方法进行粗产物的提纯,当乙醇体积分数为25%～45%时,SOA易结晶析出,能够缩短重结晶的时间,提高产品回收率.重结晶6次后SOA纯度可达约99.9%,继续重结晶对纯度提高影响不大.采用IR、DSC、GC-MS、1H NMR对SOA进行了表征.高纯度SOA满足了在国防上的应用,对标准物质的制备奠定了基础.

Preparation of High Purity Sucrose Octaacetate

High purity sucrose octaacetate(SOA) has been prepared by the combination of its synthesis and purification. Sucrose octaacetate was synthesized by the reaction between sucrose and acetic anhydride in the presence of anhydrous pyridine which reduced the amounts of by-products and improved yield to 96%. The optimum experiment conditions were as follows:molar ratio of sucrose to anhydride and pyridine 1∶11∶0.8, reaction temperature 130～135℃,and holding time 120 min. Compared with other catalysts, the anhydrous pyridine resulted in the best purity of SOA raw product which is determined by gas chromatography (GC) to be 99.03%. Purification was carried out by the recrystallization process. Ethanol-water including 25vol%～45vol% ethanol was selected as recrystallization solvent. The purity of SOA was improved from 99.1% to 99.9%, which is the highest level of SOA for purity reported so far in the open literature, by six purification processes. Furthermore, high purity SOA was characterized by FT-IR, DSC, GC-MS, ~1H NMR.