Kinetics of the hydrochloric acid-catalysed hydrolyses of benzoic anhydrides in various dioxan–water mixtures

Abstract

Kinetic studies on the hydrolysis of some benzoic anhydrides in the presence of 0.100M-hydrochloric acid have been performed in various dioxan-water mixtures over the temperature range 50–70 °C. The kinetic data indicate that the hydrolysis of p-methoxybenzoic anhydride proceeds by an A1 mechanism, whereas benzoic anhydride and its p-t-butyl and p-chloro-derivatives hydrolyse by an A2 mechanism in the water-rich mixtures, but a shift of the reaction mechanism towards the A1 type occurs when the water content in the solvent mixture decreases.