Mercaptide anions react with chlorinated sulfones in two modes, ie nucleophilic attack on carbon with chlorine as the leaving group and/or nucleophilic attack on chlorine with concomitant carbanion formation. Mercaptide anion p K b, degree of chlorination of the sulfone substrate, and substituent effects are qualitatively assessed in terms of the propensity for nucleophilic attack at carbon or chlorine.
![[methylsulfonyl(phenylsulfanyl)methyl]sulfanylmethylbenzene Structure](https://image.chemsrc.com/caspic/468/64568-22-5.png)