Oxidation of substituted phenethyl alcohols by sodium N-chlorobenzenesulphonamide: A kinetic study

Abstract

The kinetics of the oxidation of sixp-substituted phenethyl alcohols (PEA, R=−H, −Cl, −Br, −CH3, −OCH3, and -NO2) by sodium-N-chloro-p-toluene sulfonamide (chloramine-T,CAT) in the presence of HCl was studied at 35°C. The rate shows a first order dependence on [CAT]0 and [H+]0 and a fractional order in [PEA]0 and [Cl−]0. Ionic strength variations, addition of reaction product toluene sulfonamide, and variation of the dielectric constant of the medium have no effect on the rate. The solvent isotope effect\(k_{H_2 0}^\prime /k_{D_2 0}^\prime \) amounts to about 0.90. Proton inventory studies have been made in H2O-D2O mixtures. The rates correlate satisfactorily withHammett's relationship. The reaction constant ρ was −3.3 for electron releasing substituents and −0.25 for electron withdrawing groups at 35°C. The activation parameters ΔH#, ΔS#, ΔG#, and logA were derived. ΔH# and ΔS# are linearly related, and an isokinetic relationship is observed with β=166.7K, indicating entropy as a controlling factor.