Pseudo-first-order rate constants (k(obs)) for alkaline hydrolysis of N-benzylphthalimide (1) show a nonlinear decrease with the increase in [C(m)E(n)]T (total concentration of Brij 58, m = 16, n = 20 and Brij 56, m = 16, n = 10) at constant [CH(3)CN] and [NaOH]. These nonionic micellar effects, within the certain typical reaction conditions, have been explained in terms of the pseudophase micellar (PM) model. The values of micellar binding constants (KS) of 1 are 1.04 x 10(3) M(-1) (at 1.0 x 10(-3) M NaOH) and 1.08 x 10(3) M(-1) (at 2.0 x 10(-3) M NaOH) for C(16)E(20) as well as 600 M(-1) (at 7.6 x 10(-4) M NaOH) and 670 M(-1) (at 1.0 x 10(-3) M NaOH) for C(16)E(10) micelles. The pseudo-first-order rate constants (kM) for hydrolysis of 1 in C(16)E(20) micellar pseudophase are approximately 90-fold smaller than those (kW) in water phase. The values of kM for hydrolysis of 1 in C(16)E(10) micelles are almost zero. Kinetic coupled with UV spectral data reveals significant irreversible nonionic micellar binding of 1 molecules in the micellar environment of nearly zero hydroxide ion concentration at >or=0.14 M C(16)E(20) and 1.0 x 10(-3) M NaOH while such observations could not be detected at or=3 x 10(-3) M C(16)E(10) and 7.6 x 10(-4) M NaOH, while the rate of hydrolysis of 1 is completely ceased at >or=0.05 M C(16)E(10) and 7.6 x 10(-4) M NaOH. The rate of hydrolysis of 1 at 5.0 x 10(-2) and 8.8 x 10(-2) M C(16)E(10) and 1.0 x 10(-3) M NaOH reveals the formation of presumably phthalic anhydride, whereas such observation was not observed in the C(16)E(20) micellar system under similar experimental conditions.

The values of pseudo-first-order rate constants, kobs, for hydrolysis of N-(2'-methoxyphenyl)phthalimide (1) increase linearly with increase in [HCl] over the range 5 × 10−3 - 1.0M at 8.0 × 10−5 M 1, 0.5M μ (by NaCl) and in the temperature range 30-40°C. The rate of acidic hydrolysis of N-(4'-methoxyphenyl)phthalimide (2) reveals behaviour similar to that found for 1, N-(2'-hydro-xyphenyl)phthalimide (3) and N-(4 ‘-aminophenyl)phthalimide (4). The values of kobs at 35°C and varying [HCl] give the respective rate constants for the [HCl]-independent (k0) and the [HCl]-dependent (kH) hydrolysis of 1 (at [10] = 8.0 × 10−5 M, μ = 0.5 M) as 6.74 ×10−7 s−1 and 5.47 × 10−6 M−1 s−1, 2 (at [20] = 3.0 × 10−5M, μ = 0.5 M) as 12.2 × 10−7 s−1 and 4.61 × 10−6 M−1 s−1 and 4H+ (at [40] = 2.0 × 10−4 M, μ = 1.0 M) as 5.83 × 10−7 s−1 and 15.2 × 10−6 M−1 s−1. The values of kw/k0min are of the order of 102 for 1, 2 and 4 where k0min represents the sum of the contributions of H+ - and HO- -catalysed hydrolysis towards k0 (first-order rate constant for pH-independent hydrolysis of imide) and kw is the pseudo-first-order rate constant for the uncatalysed reaction of H2O with imide.

The values of pseudo first-order rate constants, k1, for the O-cyclization and k3 for N-cyclization of N-benzylphthalamic acid 1, obtained at 0.02 M HCl and 35°C, show a respective nonlinear increase from 17.6 × 10−6 to 29.7 × 10−6 s−1 and decrease from 12.5 × 10−7 to 3.75 × 10−7 s−1 with increase in the CH3CN content from 2 to 60% v/v in mixed aqueous solvent. Increase in the CH3CN content from 60 to 90% v/v decreases k1 from 29.7 × 10−6 to 24.4 × 10−6 s−1 and increases k3 from 3.75 × 10−7 to 14.7 × 10−7 s−1. The respective values of k1 and k3 decrease nonlinearly from 16.0 × 10−6 to 3.0 × 10−6 s−1 and 14.0 × 10−7 to ~4.0 × 10−7 s−1 with increase in the content of N,N-dimethylformamide (HCONMe2) from 2 to 80% v/v in mixed aqueous solvents. These results indicate rather mild rate-retarding effects of mixed H2O—CH3CN and H2O—HCONMe2 solvents on the rates of the intramolecular reactions.