Kinetics and mechanism of the oxidation of substituted benzyl alcohols by sodium N-chlorobenzenesulphonamide

Abstract

The kinetics of the oxidation of benzyl alcohol and eight monosubstituted benzyl alcohols by sodium N-chlorobenzenesulphonamide in acid solution has been studied. The reaction is of first order with respect to each of the oxidant, the alcohol, and the acidity. The primary kinetic isotope effect (k_H/k_D) is 4.41 ± 0.08 at 308 K. The solvent isotope effect (k_H2O/k_D2O) is 0.413 at 303 K. The activation enthalpies and entropies are linearly related. The reaction exhibited a reaction constant ρ⁺ of –2.14 at 298 K. The probable oxidising species is PhSO₂NHCl. A mechanism involving transfer of hydride ion to the oxidant is suggested.