Under ultraviolet irradiation or in the presence of organic peroxide, benzene-sulfenyl chloride added to phenylacetylene, yielding phenylthio-β-chlorostyrcne, different solvents having no effect upon the reaction.Under the same condition, benzene-sulfenyl chloride added to biphenylacetylene and stilbene, yielding 1, 2-diphenyl-1-phenylthio-2-chloroethylene (1) and 1, 2-Biphenyl-l-phenylthio-2-chloroethan) (1') respectively, Oxidation of 1 and 1' with H₂O₂ in glacial acetic acid converted them into the corresponding sulfones, 1,2-Biphenyl-7-benzenesulfonyl-2-chloroethylcne (2) and 1,2-Biphenyl-1-benzenesulfonyl-2-chlorethane (2').