Condensation of ethyl phenylacetate with diethyl carbonate in the presence of sodium gave diethyl phenylmalonate,whose reaction with lithium aluminum hydride yielded 2-phenyl-1,3-propanediol.After a series of functional transformation in the presence of carbon tetrabromide/triphenylphosphine,potassium thioacetate and hydrazine hydrate,2-phenyl-1,3-propanedithiol had been obtained.