Abstract A new method of synthesis of phosphonic and thiophosphonic chlorides is offered, based on treatment of acyclic and cyclic organylchlorophosphonium hexachlorophosphorates with dimethylformamide, dimethylacetamide, or dimethylthioacetamide. The method involves no formation of phosphoryl chloride and thiophosphoryl chloride, which facilitates isolation of the target products. The reactions of ...