Kinetic and Mechanistic Studies of Some Aliphatic Amines' Oxidation by Sodium N-bromo-p-toluenesulfonamide in Hydrochloric Acid Medium

摘要

Oxidations of n-propyl, isobutyl, and isoamyl amines by bromamine-T(BAT) in HCl medium have been kinetically studied at 30degC. The reaction rate shows a first-order dependence on [BAT], a fractional-order dependence on [amine], and an inverse fractional-order dependence on [HCl]. The additions of halide ions and the reduction product of BAT, p-toluenesulfonamide, have no effect on the reaction rate. The variation of ionic strength of the medium has no influence on the reaction. Activation parameters have been evaluated from the Arrhenium and Eyring plots. Mechanisms consistent with the preceding kinetic data have been proposed. The protonation constant of monobromamine-T has been evaluated to be 48+-1. A Taft linear free-energy relationship is observed for the reaction with #sigma#=-12.6, indicating that the electron-donating groups enhance the reaction rate. An isokinetic relationship is observed with #beta#=350 K, indicating that enthalpy factors control the reaction rate.