Preparation and Characterization of 4,4′-Thiodibenzenethiol

4,4′-Thiodibenzenethiol was prepared using 4-nitrochlorobenzene as starting material through five steps of substitution,reduction,diazotization,esterification and alkaline hydrolysis-acidification.The obtained optimum conditions of reduction were n(4,4′-dinitrodiphenyl sulfide)∶n(hydrazine hydrate)=1∶3.03,amount of catalyst FeCl3 7% based on the weight of 4,4′-dinitrodiphenyl sulfide,reaction temperature 60~65 ℃ and reaction time 3 h.The final yield of 4,4′-thiodibenzenethiol was about 50% with the purity of 99.5%.The structure of the product was confirmed by IR,GC-MS and 1H NMR.