Process for the preparation of the herbicide ethyl alpha-2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1h-1,2,4-triazol-1-yl]-4-fluorobenzenepropanoate
申请人:FMC CORPORATION
公开号:EP1273232A1
公开(公告)日:2003-01-08
There is disclosed a process for the preparation of a compound of formula (I):
comprising: (i) forming a diazotized salt of 4-difluoro-methyl-4,5-dihydro-3-methyl-5-oxo-1-(5-amino-2-fluoro-4-chlorophenyl)-1H-1,2,4-triazole by reacting a salt of 4-difluoro-methyl-4,5-dihydro-3-methyl-5-oxo-1-(5-amino-2-fluoro-4-chlorophenyl)-1H-1,2,4-triazole with sodium nitrite; and (ii) simultaneously reacting said diazotized salt of 4-difluoro-methyl-4,5-dihydro-3-methyl-5-oxo-1-(5-amino-2-fluoro-4-chlorophenyl)-1H-1,2,4-triazole, as it is produced in step (i), with ethyl acrylate in the presence of a Meerwein arylation catalyst to obtain a compound of formula (I).
本发明公开了一种制备式(I)化合物的工艺:
包括(i) 将 4-二氟甲基-4,5-二氢-3-甲基-5-氧代-1-(5-氨基-2-氟-4-氯苯基)-1H-1,2,4-三唑的重氮化盐与亚硝酸钠反应,形成 4-二氟甲基-4,5-二氢-3-甲基-5-氧代-1-(5-氨基-2-氟-4-氯苯基)-1H-1,2,4-三唑的重氮化盐;和(ii)同时将步骤(i)中制备的所述 4-二氟-甲基-4,5-二氢-3-甲基-5-氧代-1-(5-氨基-2-氟-4-氯苯基)-1H-1,2,4-三唑的重氮化盐在 Meerwein 芳基化催化剂存在下与丙烯酸乙酯反应,得到式(I)化合物。