硫酸氢钠催化合成2,4-滴丁酯

研究了在硫酸氢钠催化条件下,以2,4-二氯苯氧乙酸和正丁醇为原料合成除草剂2,4-二氯苯氧乙酸正丁酯的方法。考察了醇酸摩尔比、反应时间和催化剂用量等因素对反应的影响。确定其最佳的反应条件为:酸醇摩尔比为:1∶5,回流反应2.0 h,催化剂用量为0.3 g(基于0.1 mol的2,4-二氯苯氧乙酸),在此条件下酯化率达98.3%。本实验操作方便,反应条件温和,产品纯度和收率较高,避免了浓硫酸催化的种种缺点,具有工业化应用前景。

Synthesis of 2,4-D butylate with Sodium Bisulfate Catalyst

Herbicide 2,4-D butylate(butyl 2,4-dichlorophenoxyacetate) was synthesized from 2,4-dichlorophenoxyacetic acid and n-butanol with sodium bisulfate monohydrate as catalyst.The effects of molar ratio of alcohol to acid,reaction temperature and amount of catalyst on product yield were investigated.The optimum condition were as follows: molar ratio of alcohol to acid,5∶1;reflux reaction time,2.0 h;and catalyst amount,0.3 g(based on 0.1 mol of 2,4-dichlorophenoxyacetic acid).The ester yield was up to 98.3 %.This method has the advantages of simple operation,mild reaction conditions and high purity and yield of the product.Also it avoids the shortcoming of using concentrated sulfuric acid as catalyst,so it is of value to industrial production.