二氧化钛负载磷钨杂多酸催化合成苯甲醛1,2-丙二醇缩醛

Synthesis of benzaldehyde 1,2-propanediol acetal 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,以苯甲醛和1,2-丙二醇为原料合成苯甲醛1,2-丙二醇缩醛,较系统地研究了原料摩尔比、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(苯甲醛)∶n(1,2-丙二醇)=1∶1.5,催化剂用量为反应物料总质量的0.5%,环己烷为带水剂,反应时间1.0 h。上述条件下,苯甲醛1,2-丙二醇缩醛的收率为80.7%。

A new environmental friendly catalyst, phosphotungstic acid on active TiO2 （H3PW12O40/TiO2） was prepared. Benzaldehyde 1,2 - propanediol acetal （ Ⅰ ） was synthesized from benzaldehyde （ Ⅱ ） and 1,2 - propanediol （ Ⅲ） in the presence of H3PW12O49/TiO2 （ Ⅳ ）. The 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： 1.5, w （ Ⅳ ） = 0.5 % , and reaction time 1.0 h, the yield of （ Ⅰ） can reach 80.7%.