ABSTRACT

Kinetic studies were performed on the N®N’ intramolecular aroyl transfer in N-aroyl-N-aryl-N’-methyl-ethylenediamines, to give N-aroyl-N’-aryl-N-methylethylene-diamines.  Experiments were carried out over the pH 7.00-14.30 range in aqueous buffer solutions at different temperatures.  Structure-reactivity relations accounted for the attained experimental results.  Thermodynamic parameters were calculated and analyzed.

On the basis of experimental results, a mechanism is proposed which involves formation and catalyzed decomposition of a tetrahedral intermediate.  Such decomposition is associated to a diffusion-controlled proton transfer process related to the breakdown of the intermediate when this step is rate determining of the reaction.  Bearing in mind the stationary state treatment, the following equation was derived from the proposed mechanism: k_obs = k₁k₂[HO^-]/(k_-1+k₂[HO^-]), which closely fit experimental data.