申请人:Zeneca Limited
公开号:US05723649A1
公开(公告)日:1998-03-03
The invention provides an improved process for the preparation of a lower alkyl ester of 3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropane carboxylic acid in which the corresponding lower alkyl ester of a carboxylic acid selected from 6-bromo-6-chloro-3,3-dimethyl-7,7,7-trifluorohept-2-enoic acid and 6,6-dichloro-3,3-dimethyl-7,7,7-trifluorohept-2-enoic acid is treated with an alkali metal lower alkoxylate in the presence of an aromatic hydrocarbon solvent under conditions under which the lower alcohol of the alkoxylate is removed from the reaction mixture by distillation with the aromatic solvent. The products are useful as intermediates in the manufacture of pyrethroid insecticides.
该发明提供了一种改进的工艺,用于制备3-(2-氯-3,3,3-三氟丙-1-烯-1-基)-2,2-二甲基环丙烷羧酸的较低烷基酯,其中所述较低烷基酯是从6-溴-6-氯-3,3-二甲基-7,7,7-三氟庚-2-烯酸和6,6-二氯-3,3-二甲基-7,7,7-三氟庚-2-烯酸中选择的羧酸的相应物,在芳香烃溶剂存在下,在较低烷基醚醇酸盐的条件下处理,通过在芳香溶剂中蒸馏去除醚醇酸盐的较低醇,反应产物可用作合成拟除虫剂中间体。