The acid-catalysed hydrolysis of diaryl carbonates

Abstract

The rates of hydrolysis of diphenyl and bis-(4-nitrophenyl) carbonates have been studied in aqueous acidic dioxan. The dependence of rate on acid concentration for the hydrolysis of diphenyl carbonate passes through a maximum in perchloric acid but not in hydrochloric or sulphuric acid. It is shown that the rate maximum in perchloric acid is not due to extensive protonation of the substrate as for amides but arises from specific electrolyte effects on the high neutral rate. All the acids studied decrease the rate of hydrolysis of bis-(4-nitrophenyl) carbonate. This decrease again reflects large negative salt effects on the neutral rate but rate measurements at constant ionic strength suggest the occurrence of very weak acid catalysis.