二氧化钛负载磷钨杂多酸催化合成苹果酯

介绍了以自制二氧化钛负载磷钨杂多酸（H3PW12O40/TiO2）为多相催化剂,乙酰乙酸乙酯和乙二醇为原料合成苹果酯的方法.考察了原料摩尔比、催化剂用量、反应时间诸因素对苹果酯产品收率的影响.实验结果表明,二氧化钛负载磷钨杂多酸是合成苹果酯的良好催化剂,在乙酰乙酸乙酯与乙二醇摩尔比为1：1.5,催化剂用量占反应物料总量的0.8%,环己烷为带水剂,其用量8 mL,反应时间1.0 h的优化条件下,苹果酯的收率为78.2%.

Synthesis of 2 - Methyl - 2 - ethoxycarbonylmethyl - 1,3 - dioxolane Using H3PW12O4o/TiO2 as Catalyst

2-Methyl-2-ethoxycarbonylmethyl-1,3-dioxolane was synthesized from ethyl acetoacetate and ethylene ethylene glycol as raw materials using self-made TiO_2 supported H_3PW_(12)O_(40)as heterogeneous catalyts. The effects of reaction conditions such as molar ratio of raw materials,catalyst amount and reaction time on the yield of the product were examined.The result showed that the yield of the product was 78.2% under the following opti- mum conditions showing H_3PW_(12)O_(40)/TiO_2 was a good catalyst for synthesis of the titled compound.The optimum conditions were as follows:molar ratio of ethyl acetoacetate to ethylene glycoo of 1:1.5,mass percentage of catalyst 0.8%(based on the total reactants),dosage of cyclohexane as water carrying agent 8 mL,reaction time of 8 h.