Studies on phosphoroheterocycle chemistry III: An unusual way to 1,3,2-thiazaphospholidine-4-thione 2-sulfide derivatives

An unusual but efficient method for the synthesis of phosphoroheterocycles, 1,3,2-thiazaphospholidine-4-thione 2-sulfide derivatives, by the reaction of Lawesson's reagent with a variety of alpha-hydroxy nitriles has been developed. The possible mechanism of the reaction is proposed to involve thiation of hydroxy group in a first step, sequential addition of P-SH to the nitrile and rearrangement resulting in the title phosphoroheterocycles. The preliminary bioassays show that these heterocyclic compounds have herbicidal properties.