The Kinetics of the Aminolysis of Phenyl Phenoxyacetates with Benzylamine in Dioxane

Abstract

Abstract The rates of the reactions of p- and m-substituted phenyl phenoxyacetates with benzylamine in dioxane, thus forming N-benzylphenoxyacetamide and the corresponding phenols, were followed by the non-aqueous titration of benzylamine. The reaction satisfied the following general equation: ν={k_2’+k_3’[Amine]}[Amine][Ester]+{k_3”+k_4[Amine]}[Amine][Ester]^2. The reaction was a neucleophilic substitution, and the Hammett plots gave straight lines with positive ρ values. A marked enhancement in the conductivity of the reaction mixtures in 50% dioxane was observed, it increasing with the reaction time. A probable mechanism was presented which involves an ion pair of the quaternary ammonium salt type somewhat similar to that discussed in a previous paper (Y. Furuya, S. Goto, K. Itoho, I. Urasaki and A. Morita, Tetrahedron, 24, 2367 (1968)).