Method of reducing the contents of haloethynyl-containing impurities in synthetic dihaloethenyl pyrethroid insecticides or intermediates by reaction with phosphites

摘要

A method of reducing the content of a haloethynyl-containing impurity in a synthetic dihaloethenylcyclopropanecarboxylate by treatment with a phosphite under condition allowing the haloethynyl-containing impurity and phosphite to chemically interact, and thereafter recovering the dihaloethenylcyclopropanecarboxylate from the reaction mixture is disclosed.