Acylation. Part XXXV. The silver ion-catalysed n-butaminolysis of S-ethyl thiobenzoate in aqueous solutions

Abstract

Silver ions catalyse the n-butaminolysis of S-ethyl thiobenzoate in aqueous solution. The catalysed reaction involves the ester and the 1 : 1 - and 2 : 1-complexes, (I) and (II) respectively, of n-butylamine with Ag⁺. The rate equation is: –d[Ester]/dt={k₁[(I)]+k₂[(II)]}[Ester]. At 26 °C the complex (I) is about twice as reactive as complex (II). A path via reaction of the ester with free silver ions and free butylamine makes a negligible contribution to the velocity. The mechanism probably involves a cyclic transition state in which the metal ion holds the ester and amine in close juxtaposition.