申请人:JAPAN SCIENCE AND TECHNOLOGY CORPORATION
公开号:EP1334960A1
公开(公告)日:2003-08-13
The present invention provides a method for preparing ester or thioester that can conduct catalytic esterification reaction with an equimolar amount of carboxylic acid and alcohol, or catalytic thioesterification reaction with carboxylic acid and an equimolar amount or small amount of thiol, and can be expected as an industrial method that needs an enormous amount of synthesis in the light of green chemistry. By using hafnium chloride (IV), especially tetravalent hafnium compounds represented by hafnium chloride (IV) · (THF)2 or hafnium (IV)t-butoxide as a (poly) condensation catalyst, direct condensation reaction is conducted from carboxylic acid and an equimolar amount of alcohol or a little smaller amount of thiol , in the nonpolar solvent such as toluene and the like, in a deoxidization atmosphere and under heating reflux, and the reaction synthesizes ester monomer or thioester monomer, polyester or polythioester. When heating reflux is conducted by using a nonpolar solvent, it is preferable to remove azeotropic water from the reaction system.
本发明提供了一种制备酯或硫酯的方法,该方法可与等摩尔量的羧酸和醇进行催化酯化反应,或与等摩尔量或少量的羧酸和硫醇进行催化硫酯化反应,可望成为一种在绿色化学背景下需要大量合成的工业方法。使用氯化铪(IV),特别是以氯化铪(IV)-(THF)2 或四价氧化铪(IV)-t-丁醇为代表的四价铪化合物作为(多)缩合催化剂,在非极性溶剂(如乙醇)中与等摩尔量的羧酸和等摩尔量或少量的硫醇进行直接缩合反应、在非极性溶剂(如甲苯等)中,在脱氧气氛和加热回流条件下进行直接缩合反应,合成酯单体或硫酯单体、聚酯或聚硫酯。使用非极性溶剂进行加热回流时,最好去除反应体系中的共沸水。