The conditions of the reaction of trichloroethylene with sulfur and amines were optimized (the modified Willgerodt-Kindler reaction). The reaction of tetrachloroethylene with sulfur and some basic primary and secondary amines of the aliphatic series in DMF under mild conditions leads toN,N'-disubstituted dithiooxamides in 30-70% yields and with a 100% conversion of tetrachloroethylene.