Kinetic and equilibrium studies of ?-adduct formation and substitution in the reactions of sulphite ions with some alkyl and aryl ethers and thioethers

Abstract

Kinetic and equilibrium results are reported for the reactions of sulphite with the ethyl and phenyl ethers of 2,4,6-trinitrophenol and 2,4,6-trinitrothiophenol in 80/20 (v/v) water/DMSO. In each case 1:1 and 1:2 adducts are observed by reaction of sulphite at one or two unsubstituted ring positions respectively. In the case of the ethyl derivatives these adducts are long-lived; however, the phenyl derivatives rapidly yield 2,4,6-trinitrobenzenesulphonate, the substitution product. This difference is attributed to a change in the nature of the rate-determining step, from nucleophilic attack with the phenyl derivatives to leaving group departure with the alkyl derivatives.