Abstract: Forty-two compounds, among them thirty-four new compounds of S-alkyl O-aryl thiophosphoric derivatives have been synthesized by using a new convenient method which is based on the isomerization-chlorination of O,O-dialkyl O-aryl phosphorothionate with phosphoryl chloride to give S-alkyl O-aryl thiophosphorochloride. Then, this thiophosphorochloride reacts with various nucleophiles, e. g. alcohol, phenol, mercaptan, thiophenol, ammonia, amine, in the presence of acid-binding agent to obtain S-alkyl O-aryl thiophosphoric derivatives, e. g. S-alkyl O-alkyl (or aryl) O-aryl phosphorothiolate, S-alkyl S-alkyl (or aryl) O-aryl phospho-rodithiolate, S-alkyl O-aryl phosphorothiolamide. The insecticidal activities of the compounds prepared towards bean aphid (Aphis laburni), cotton red spider (Tetranychus telarius), army worm(Leucania separata) and house fly (Musca domestica) have also been tested.

Key words: Phosphorothiolate, Phosphorodithiolate, Phosphorothiolamide, Isomerization-chlori-nation, Insecticide