磷钨酸镧催化合成缩醛(酮)的研究

Synthesis of Acetals and Ketal Catalyzed by LaPW_(12)O_(40)

以磷钨酸镧为催化剂催化合成了苯甲醛乙二醇缩醛、苯甲醛1,2-丙二醇缩醛及环己酮乙二醇缩酮.较系统研究了反应物料配比、催化剂用量、反应时间、催化剂重复使用性能等因素对反应的影响.结果表明:在醛(酮)/二元醇(乙二醇、1,2-丙二醇)=1.0:1.5(mol/mol),催化剂用量为反应物料总质量的1.0%,环己烷为带水剂,在反应温度86～96℃条件下,反应时间2.0h,苯甲醛乙二醇缩醛收率为78.5%,苯甲醛1,2-丙二醇缩醛收率为76.1%,环己酮乙二醇缩酮收率为79.5%.

Benzaldehyde glycol acetal, benzaldehyde 1,2-propanediol acetal and cyclohexanone ethylene Ketal were synthesized in the presence of LaPW12O40. The various factors influencing the synthesis were investigated and the optimum conditions were found as follows： based on aldehyde/ketone 0.1 mol, the molar ratio of aldehyde or ketone to glycol is 1.0/1.5 （ mol/mol）, the mass percent of catalyst is the reactants 1.0%, the amount of cyclohexane 12mL, reaction temperature 86-96℃, reaction time 2.0h. Under the above conditions, the yield of benzaldehyde glycol acetal is 78.5% , benzaldehyde 1,2-propanediol acetal 78.1%, cyclohexanone ethylene Ketal 79.5% respectively