Method of preparation of O-alkyl-S-alkyl-dithiophosphoric acid chlorides

摘要

O-Alkyl S-alkyl dithiophosphoric acid chlorides are prepared by reaction of salts of O,S-dialkyl dithiophosphoric acid esters with phosphorus pentachloride in the absence of a diluent or solvent. Phosphoric acid ester salts employed here are those which are liquid under the reaction conditions. According to this process, O-alkyl S-alkyl dithiophosphoric acid chlorides of the formula IMAGE can be prepared in which R1 and R2 are identical or different and denote alkyl radicals having 1 to 4 carbon atoms. These phosphoric acid chlorides are useful starting substances for the synthesis of insecticidal active substances.