二氧化硅负载硅钨钼酸催化合成苹果酯

Catalytic synthesis of 2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane with H_4SiW_6Mo_6O_(40)/SiO_2

采用溶胶-凝胶法制备了二氧化硅负载硅钨钼酸催化剂。以其为催化剂,以乙酰乙酸乙酯和乙二醇为原料合成了苹果酯,探讨二氧化硅负载硅钨钼酸对苹果酯合成反应的催化活性。用正交实验法较系统地研究了反应物料配比、催化剂用量、带水剂用量、反应时间等因素对产物收率的影响。实验表明,二氧化硅负载硅钨钼酸是合成苹果酯的良好的催化剂,固定乙酰乙酸乙酯的用量为0.20mol,在n(乙酰乙酸乙酯):n(乙二醇)=1:1.5,催化剂用量为反应物料总质量的1.0%,带水剂环己烷8mL,反应时间60min的优化条件下,苹果酯的收率可达72.8%。

A novel catalyst,H4SiW6Mo6O40 /SiO2 was synthesized by a sol-gel technique,and characterized by FTIR and XRD.2-Methyl-2-ethoxycarbonylmethyl-1,3-dioxolane was synthesized from ethyl acetoacetate and ethylene glycol in the presence of H4SiW6Mo6O40 /SiO2 as catalyst.The factors influencing the synthesis were discussed and the best reaction conditions were found out.Experimental results showed that H4SiW6Mo6O40 /SiO2 is an excellent catalyst.Under the exeperimental conditions as follows：molar ratio of ethyl acetoacetate to ethylene glycol is 1：1.5,the mass ratio of the catalyst is 1.0% of all the reactants,volume of cyclohexane is 8mL,and the reaction time is 60 min,the yield of 2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane can reach 72.8 %.