Effects of Cationic Micelles on the Rate of Alkaline Hydrolysis of N-(2-methoxyphenyl)phthalimide

Pseudo-first-order rate constants (kobs), obtained for the reaction of N-(2-methoxyphenyl)phthalimide (1) with HO- at a constant [NaOH] and varying concentrations of cetyltrimethylammonium bromide ([CTABr](T) = 0.0-0.20 M), have been analyzed in terms of both pseudophase ion-exchange (PIE) model and Berezin's pseudophase (BPP) model. Although both models give the best observed data fit with least-squares values not significantly different from each other, the calculated values of K-S from BPP model appear to be more reliable compared to those from PIE model. The nonlinear decrease of k(obs) with the increase of [NaBr] at the constant [NaOH] and [CTABr](T) is explained in terms of pseudophase micellar model coupled with an empirical equation which could indirectly give the measure of the ion-exchange Br-/HO-.