The reaction of thionophosphine sulfides (RPS,),, with alcohols and phenols has been found to give excellent yields of the corresponding 0-alkyl and 0-aryl phosphonodithioic acids. A number of halo-alkanols, alkenols, and dihydric alcohols, as well as simple primary and secondary alcohols have been smoothly converted to phosphonodithioic acids. Chlorination of these 0-alkyl and 0-aryl phosphonodithioic acids has been found to yield the ...