二氧化钛负载磷钨钼杂多酸催化合成苯甲醛乙二醇缩醛  

Catalytic Synthesis of Benzaldehyde Glycol Acetal with H_3PW_6Mo_6O_(40)/TiO_2

作　　者：杨水金[1] 杨斌[1] 

机构地区：[1]湖北师范学院化学与环境工程系,湖北黄石435002

出　　处：《精细与专用化学品》2008年第6期25-26,共2页Fine and Specialty Chemicals

基　　金：湖北省自然科学基金(2005AABA053)

摘　　要：苯甲醛乙二醇缩醛是一种有着优于母体羰基化合物的花香、果香或特殊香味的香料,香气柔和,留香持久,香气类型多,原料来源丰富,常用于有机合成的羰基保护或作为反应中间体,同时还可用做反应溶剂。苯甲醛乙二醇缩醛的工业合成一般是在无机质子酸类物质的催化下由醛与醇类化合物缩合而成。虽然这类催化剂价格低廉,产品收率较高,但该法存在副反应多,产品纯度不高,设备腐蚀严重,产生大量酸性废水等缺点。文献报道,FeCl_3·6H_2O、NH_4Fe(SO_4)_2、H_3PMo_(12)O_40、Vitamin C、SO_4^(2-)/TiO_2-SnO_2等固体酸催化剂对合成苯甲醛乙二醇缩醛具有良好的催化作用。新型环境友好绿色催化剂——杂多酸及其盐类开发研究日益受到人们关注。本研究在文献[9]基础上改进H_3PW_6Mo_6O_(40)/TiO_2的制备方法,并以改进后的H_3PW_6Mo_6O_(40)/TiO_2为催化剂,通过苯甲醛和乙二醇反应合成了苯甲醛乙二醇缩醛,系统考察了物料配比,催化剂用量以及反应时间等产品收率的影响。Benzaldehyde glycol acetal was synthesized based on reaction of benzaldehyde and glycol with H_3PW_6Mo_6O_(40) as catalyst loaded on TiO_2 Various factors such as ratio between benzaldehyde and glycol,dosage of catalyst and reaction time concerned in the reaction have been investigated. The optimum conditions have been found,i.e.the molar ratio of benzaldehyde to glycol is 1/1.5,the mass ratio of the used catalyst to the reactants is 0.8%,volume of cyclohexane used as water-carrying agent is 8 mL,and the reaction time is 0.5 h.Under these conditions,the yield of benzaldehyde glycol acetal is 70.3%.

关 键 词：苯甲醛乙二醇缩醛 磷钨钼杂多酸 催化合成 二氧化钛 固体酸催化剂 羰基化合物 负载 产品收率 

分 类 号：TQ244.1[化学工程—有机化工]