A simple and new method for the synthesis of phosphoroheterocycles 1,3,2-diazaphospholidine-4-thione 2-sulfide derivatives by treatment of Lawesson’s reagent (LR) with a variety of α-aminonitriles has been developed. The same methodology was also used in the preparation of fused phosphoroheterocycle 6 from 5-amino-4-cyano-3-methylthia-1-phenylpyrazole. The possible mechanism of the reaction involving addition of P-SH to the nitrile and subsequent rearrangement is proposed.
α-aminonitriles - Lawesson’s reagent - phosphoroheterocycle
