The acid-catalyzed hydrolysis of arylsulfonyl phthalimides was studied in aqueous solutions of sulfuric, perchloric, and hydrochloric acid at 35.0±0.1° C. Analysis of the data by the excess acidity method and activation parameters, as well as substituent and solvent isotope effects, indicate hydrolysis by an A-2 mechanism at low acidity. At higher acidities, a changeover to an A-1 mechanism is observed.
