Oxidation of Substituted Phenethyl Alcohols by Sodium-N-chloro-p-toluene sulfonamide: A Kinetic Study

Article abstract of DOI:10.1007/BF00813789

The kinetics of the oxidation of six p-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 [Cr^-]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′_H2O/k′_D2O amounts to about 0.90. Proton inventory studies have been made in H₂O-D₂O mixtures. The rates correlate satisfactorily with Hammett'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 = 166.7 K, indicating entropy as a controlling factor.