(3-磺酸丙基)三苯基膦磷钨酸盐催化合成糠酸正丁酯

摘要

以三苯基膦、1,3-丙磺酸内酯和磷钨酸为原料,采用两步法合成了(3-磺酸丙基)三苯基膦磷钨酸盐催化剂(简写为[ TPSPP]3 PWi2O40)；采用ESI - MS,NMR,FTIR等方法对该催化剂进行了表征,并用其催化糠酸与正丁醇进行酯化反应；同时与多种Keggin型杂多酸及其盐、用浸渍法制备的SiO2负载型催化剂进行了催化性能比较；考察了催化剂用量、原料配比、油浴温度和反应时间对酯化反应的影响.实验结果表明,[ TPSPP]3 PW12O40具有很高的催化性能和较好的重复使用性能；糠酸与正丁醇进行酯化的适宜条件为:糠酸20 mmol,n([TPSPP] 3PW12O40)∶n(正丁醇)∶n(糠酸)=0.005∶5.4∶1,油浴温度150℃,反应时间3h；在此条件下,糠酸正丁酯的收率达到96.9％,催化剂可以循环使用4次.%3-Sulfopropyl)triphenyl-phosphine phosphotungstate catalyst ([TPSPP]3PW12O40) was synthesized from triphenylphosphine, 1,3-propane sultone and phosphotungstic acid through two step reactions and characterized by means of ESI-MS, NMR and FTIK. Its catalytic performance in esterification of furoic acid with ra-butanol to n-butyl furoate was evaluated. Several heteropoly compounds with Keggin-structure were prepared and supported on porous silica by impregnation. Their catalytic performances in the esterification were compared with [TPSPP]3PW12O40 catalyst. The effects of catalyst dosage, mole ratio between the reactants, oil bath temperature and reaction time on the n-butyl furoate yield were investigated. Under the optimal reaction conditions; furoic acid 20 mmol, n( [TPSPP]3PWl2O40) : n(n-butanol) : n(furoic acid) 0.005 =5.4 : 1, oil bath temperature 150 ℃ and reaction time 3 h, the n-butyl furoate yield could reach 96.9% and the catalyst could be recycled four times.