三氟甲磺酸催化便捷高效合成2,4-滴丁酯除草剂

以2,4-二氯苯氧乙酸与正丁醇为原料,三氟甲磺酸为催化剂,催化合成2,4-滴丁酯,考察了醇酸摩尔比、反应时间及催化剂用量等对反应的影响。结果表明,合成2,4-滴丁酯的最佳反应条件是:正丁醇与2,4-二氯苯氧乙酸的摩尔比为3∶1,催化剂用量为0.2%(占2,4-二氯苯氧乙酸摩尔量),回流反应8 h,在此条件下,酯化率达97.1%。

Efficient and convenient synthesis of 2,4-D butylate herbicide catalyzed by trifluoromethanesulfonic acid

Esterification of 2,4-dichlorophenoxyacetic acid and n-butanol as raw materials, then catalyzed by trifluoromethanesulfonic acid（TfOH） led to 2,4-D butylate. The effects of mole ratio of reactants, reac tion time and catalyst amount on the esterification rate were investigated. The optimized conditions for syn thesis of 2,4-D butylate were obtained as follows：the mole ratio of n-butanol to 2,4-diehlorophenoxyacetic acid was 3 ： 1 ,catalyst amount was0.2% （based on the 2,4-dichlorophenoxyacetic acid mole amount）, and the reaction time was 8 h. Under these conditions,the esterification rate was 97.1%.