分子碘催化合成24,-滴丁酯

Catalytic Synthesis of 2,4-D Butyl Ester by Molecular Lodine

研究了在分子碘催化条件下,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(2,4-滴丁酯)的方法。考察了醇酸物质的量比、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:醇酸物质的量比为:10:1,回流反应2.0 h,催化剂用量为0.03g(基于0.02mol的24,-二氯苯氧乙酸),在此条件下酯化率达98.7%。与现有的24,-滴丁酯的合成方法相比本方法操作方便,反应条件温和,产品纯度和收率较高,具有工业化应用前景。

Herbicide 2,4 - D butyl ester （ butyl 2,4 - dichlorophenoxyacetate） was synthesized from 2,4 -dichlorophenoxyacetic acid （2,4 -D）and n -butanol with molecular iodine as catalyst. The effects of molar ratio of alcohol to acid, reaction time and amount of catalyst on product yield were investigated. The optimal conditions were as follows ： molar ratio of alcohol to acid 10 ： 1, reflux reaction time 2.0 h, and catalyst amount 0.3g （ based on 0.02 tool of 2,4 - dichlorophenoxyacetic acid）. The ester yield was up to 98.7%. This method has the advantages of simple operation, mild reaction conditions and high purity and yield of the product. Over the existing alternatives, this research is applicable in industrial production.