KINETICS AND MECHANISM OF THE AMINOLYSIS OF BENZOIC ANHYDRIDES

Article abstract of DOI:10.1002/poc.610070602

Nucleophilic substitution reactions of benzoic anhydrides, in which one of the rings is substituted, with anilines were investigated in methanol.The product-formation step coincides with the rate-limiting step so that the two rate constants, k_XY and k_XZ, for the competitive reaction pathways can be dissected.The two cross-interaction constants, ρ_XY and ρ_XZ, especially an unusually large magnitude of the latter, indicate that the reaction proceeds by a frontside S_N2 attack on either one of the carbonyl carbon with a strong interaction between the nucleophile (X) and the leaving group (Z).The mechanism is also supposed by the trends in the activation parameters.