固体酸催化合成3-甲氧基-4-羟基苯乙醇酸

Synthesis of 3-Methoxy-4-hydroxymandelic Acid Catalyzed by Solid Acid

为了得到高质量和高收率的3-甲氧基-4-羟基苯乙醇酸,使愈创木酚和乙醛酸在碱性水溶液中在固体酸催化剂存在下进行缩合反应,反应温度15℃,反应时间18h。将生成的3-甲氧基-4-羟基苯乙醇酸以钠盐形式沉淀分离出来,产品纯度98%。以γ-氧化铝、4A分子筛、活性二氧化硅、轻质氧化镁和活性氧化锌等两性氧化物用做催化剂进行研究。以4A分子筛作催化剂时收率达88·6%,比无催化剂时收率提高8·8%。

In order to obtain 3-methoxy-4-hydroxymandelic acid with high quality and high yield, guaiacol was condensed with glyoxylic acid in an alkaline aqueous solution using solid acid as catalyst. The reaction temperature and reaction time was 15℃ and 18 hours respectively. The 3-methoxy-4-hydroxymandelic acid was precipitated and separated with 98% purity in the form of sodium salt. Investigation based on different kinds of amphoteric oxides such as activated alumina, molecular sieve of 4A type, activated silica, light magnesium oxide and activated zinc oxide was carried out. The resuits showed that the molecule sieve type 4A was used as catalyst, the yield of condensation reaction was 88.6%. It was increased 8.8% compared with that without any catalyst.