二氧化钛负载磷钨杂多酸催化合成苹果酯-B

Synthesis of Ethyl Acetoacetate 1,2-Propanediol Ketal by Using H_3PW_(12)O_(40)/TiO_2 as Catalyst

以自制二氧化钛负载磷钨杂多酸H3PW12O40/TiO2为多相催化剂,以乙酰乙酸乙酯和1,2-丙二醇为原料合成苹果酯-B,研究了原料摩尔比、催化剂用量、反应时间诸因素对产品收率的影响。实验表明:适宜反应条件为n(乙酰乙酸乙酯)∶n(1,2-丙二醇)=1∶1.4,催化剂用量为反应物料总质量的0.8%,环己烷为带水剂,反应时间1.0h。上述条件下,苹果酯-B的收率为76.3%。

A new environmental friendly catalyst, phosphotungstic acid on active TiO2 （H3PW12O40/TiO2） was prepared. Ethyl acetoacetate 1,2-propanediol ketal （Ⅰ） was synthesized from ethyl acetoacetate （Ⅱ） and 1,2-propylene glycol （Ⅲ） in the presence of H3PW2O40/TiO2 （Ⅳ）. Factors influencing the product yield were discussed and the best reaction conditions were found. Experimental result showed that IV is an excellent catalyst. With n（Ⅱ）：n（Ⅲ）=1.0：1.4, w （Ⅳ）=0.8%, and reaction time=1.0h, yield of （ Ⅰ ） can reach 76.3%.