VERFAHREN ZUR HERSTELLUNG VON 3-(2-CHLOR-2(4-CHLORPHENYL)-VINYL)-2,2-DIMETHYLCYCLOPROPANCARBONSAEURE.

摘要

3-(2-chloro-2-(4-chlorophenyl) -vinyl)-2,2-dimethyl cyclopropanecarboxylic acid (I), its esters and derivs. are prepd. by the stages of (i) reacting 3-chloro-3-(4-chlorophenyl)-propenal (II) with chloromethyl- isopropylketone (III) to form 4,4-dimethyl-1,3,6-trichloro -1-(4-chlorophenyl) -1-hexen-5-one (IV) and (ii) converting the resulting (IV), opt. without isolation, in the presence of aq. bases or in the presence of alcoholates to form (I) or its esters, and opt. (iii) derivatising the prod. in the usual way. Specifically stage (i) is carried out e.g. at -20 to +30 deg. C, esp. 0 to +20 deg. C at normal or elevated press., with or without a diluent such as CH2Cl2, CHCl3, CCl4, THF, etc., using ca. equimolar amts. of (II) and (III) and in the presence of an at least equimolar amt. of HC1.