Polar effects in hydrogen abstraction from benzaldehydes. Part IV. Solvent effect on chlorination by sulphuryl chloride
Abstract
Enhancement of the reactivity of benzaldehyde relative to cyclohexane towards sulphuryl chloride at 40° in CCl4 was demonstrated by modifying the reactivity of the hydrogen-abstractor radical in the rate-determining step with added benzene and t-butylbenzene which are able to complex with atomic chlorine. Relative rates of chlorination of substituted benzaldehydes with SO2Cl2 have been determined in benzene, and in 2M-PhBut in CCl4 at 40°. The Hammett correlations with σ constants (ρ–0·68 and –0·86, respectively) are attributed to the selective benzene and t-butylbenzene π-complexed chlorine atom.