Preparation of carbon-14 labeled organophosphate pesticides

Abstract

Synthesis of [vinyl-C-14]chlorfenvinphos, utilizing [C-14]iodomethane as the source of the label, was accomplished in 28% radiochemical yield by the methylation of 2,4-dichlorobenzoyl chloride, chlorination of the resulting [C-14]-2,4-dichloroacetophenone, and condensation of the product with triethylphosphite. The product, isolated as a mixture of E and Z isomers (3.6 and 96.3%, respectively), was obtained in >99% purity and had specific activity 20 mCi/mmol.