磷钨酸催化合成乙酰化熊果酸
Synthesis of Acetylated Ursolic Acid Catalyzed by Phosphotungstic Acid

文章以四氢呋喃为溶剂，磷钨酸(H₃PW12O40·xH2O)为催化剂，乙醋酐为酰化试剂，对熊果酸催化合成乙酰化熊果酸进行研究。考察不同溶剂、反应温度、反应物物质的量比、反应时间等因素对乙酰化熊果酸收率的影响。实验结果表明，适宜的反应条件为：以四氢呋喃为溶剂，熊果酸与乙酸酐的摩尔比为1:2，熊果酸与四氢呋喃料液比(mg/mL)为20:1，磷钨酸催化剂用量为6.5% (以熊果酸的质量计)，反应温度为60℃，反应时间为3 h，乙酰化熊果酸收率最高可达91.02%。
In this paper, the synthesis of acetylated ursolic acid catalyzed by ursolic acid was studied with tet-rahydrofuran as solvent, phosphotungstic acid (H3PW12O40·xH2O) as catalyst and acetic anhydride as acylating agent. The effects of different solvents, reaction temperature, molar ratio of reactants and reaction time on the conversion of acetylated ursolic acid were investigated. The experimental re-sults showed that the suitable reaction conditions were as follows: using tetrahydrofuran as solvent, the molar ratio of ursolic acid to acetic anhydride was 1:2, the ratio of ursolic acid to tetrahydrofu-ran (mg/mL) was 20:1, and the amount of phosphotungstic acid catalyst was 6.5% (based on the mass of ursolic acid), the reaction temperature is 60？C, and the reaction time is 3 h. The highest yield of acetylated ursolic acid reached 91.02%.