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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 Ethylene glycol acetal is a fragrance with floral, fruity or special fragrance superior to the parent carbonyl compound. It has the characteristics of gentle aroma, long lasting aroma, rich aroma type and abundant raw materials. It is commonly used in carbonyl protection of organic synthesis or As a reaction intermediate, but also can be used as a reaction solvent. The industrial synthesis of benzaldehyde ethylene glycol acetal is generally formed by the condensation of aldehydes and alcohol compounds under the catalysis of inorganic protonic acids. Although this kind of catalyst is low in price and the yield of the product is high, there are many disadvantages such as many side reactions, low product purity, serious equipment corrosion and large amount of acid wastewater. It has been reported in the literature that solid acid catalysts such as FeCl 3 · 6H 2 O, NH 4 Fe (SO 4) 2, H 3 PMo 12 O 40, Vitamin C, SO 4 2- / TiO 2 -SnO 2 have good catalytic activity for the synthesis of benzaldehyde ethylene glycol acetal . The development of new environmentally friendly green catalysts-heteropoly acid and its salts has attracted more and more attention. In this study, the preparation of H_3PW_6Mo_6O_ (40) / TiO_2 was improved on the basis of the literature [9]. The benzaldehyde ethylene glycol was synthesized by the reaction of benzaldehyde and ethylene glycol with the improved H_3PW_6Mo_6O_ (40) / TiO_2 as catalyst Aldehyde, the system investigated the material ratio, the amount of catalyst and reaction time and other products yield.