Oxidation of some primary amines by bromamine-T in alkaline medium: a kinetic and mechanistic study.

摘要

The kinetics of oxidn. of the aliph. primary amines, n-propylamine, n-butylamine, and n-hexylamine, by sodium N-bromo-p-toluenesulfonamide or bromamine-T (BAT) in sodium hydroxide medium has been studied at 308 K. The reaction rate shows a first-order dependence on [BAT] and fractional-order each on [amine] and [OH-]. Addns. of halide ions and the redn. product of BAT (p-toluenesulfonamide) have no effect on the reaction rate. Also, the variation of ionic strength and dielec. const. of the medium does not have any significant effect on the reaction. Activation parameters have been evaluated. A Taft linear free-energy relationship is obsd. for the reaction with ρ* = -0.44 and δ = -1.76 indicating that electron-donating groups enhance the rate. An isokinetic relationship is obsd. with β = 355 K indicating that enthalpy factors control the rate. Mechanisms consistent with the obsd. kinetic data have been proposed. The av. value of deprotonation const. of monobromamine-T forming TsNBr- has been evaluated as 3.3 ± 0.1 × 103M at 308 K. [on SciFinder(R)]