A PROCESS FOR THE PREPARATION OF PYRETHROID INSECTICIDE ESTERS

摘要

A method for preparing a pyrethroid insecticide of general formula: (I) wherein the two hydrogen atoms on the cyclopropane ring are in the cis- configuration, in which an acid of formula: (II) is neutralized with a water-soluble base and then reacted in the presence of a phase-transfer catalyst with a solution in a substantially water-immiscible organic solvent of an alpha-cyanobenzyl aryl sulphonate of formula: (III) the substituents in the formulae having the following meanings; A represents an optionally substituted aryl group; R1 and R2 represent hydrogen or halogen; and R3 and R4 represent chlorine, bromine, or methyl.