Abstract A number of alkyl, aryl and bifunctional isothiocyanates are obtained in moderate to high yields (41–94%) in a two-step, one-pot reaction of the parent primary amines or their salts with carbondisulfide, followed by reaction of the thus formed dithiocarbamates with T3P® (propane phosphonic acid anhydride) as a new and efficient desulfurating agent. A number of alkyl, aryl and bifunctional isothiocyanates