A new and efficient synthetic method for the herbicide carfentrazone-ethyl based on the Heck reaction
作者:Jianjian Fan、Juan Yu、Xinghua Fu、Rui Liu、Guangke He、Hongjun Zhu
DOI:10.1007/s11164-014-1702-x
日期:2015.8
The herbicide carfentrazone-ethyl ( 1 ) was prepared by a new and improved synthetic method. The common and inexpensive reagent ethyl acrylate was employed to replace commercially unavailable ethyl 3-hydroxy-2-methylenebutanoate, which was used in the synthetic route reported previously. Starting from iodination of 1-(4-chloro-2-fluorophenyl)-4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1 H -1,2,4-triazole
通过一种新的改进的合成方法制备了除草剂克芬特酮-乙基( 1 )。使用普通和廉价的丙烯酸乙酯试剂来代替商业上不可用的3-羟基-2-亚甲基丁酸乙酯,该乙酯被用于先前报道的合成路线中。从1-(4-氯-2-氟苯基)-4-二氟甲基-4,5-二氢-3-甲基-5-氧代-1 H -1,2,4-三唑的碘化开始 ( 2 )将1-(4-氯-2-氟-5-碘苯基)-4-二氟甲基-4,5-二氢-3-甲基-5-氧代-1 H -1,2,4-三唑( 3 )提供给优良的产量。然后,得到中间体乙基3- [2-氯-5-(4-二氟甲基-4,5-二氢-3-甲基-5-氧代-1 H 通过 3 与丙烯酸乙酯的Heck偶联,合成了(1,2,4-三唑-1-基)-4-氟苯基] -2-丙酸酯( 4 ) 。接着,氧化加成-消除 4 用 OXONE ® /盐酸-ET 3以一个锅煮Ñ产生2-氯-3- [2-氯-5-(4-二氟甲基-4,5-二氢-3-甲基5-氧代-1