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The rates of the hydrolyses of
N-(
o-hydroxyphenyl)phth
alimide (
1) and
N-(
o-methoxyphenyl)phth
alimide(
2), studied at different pH, show that the hydrolysis of
1 involves intramolecular general base (IGB)assistance where the
o-O
- group of ionized
1 acts as IGB and H
2O as the reactant. The rate enhancementdue to the IGB-assisted reaction of H
2O with ionized
1 is >8 × 10
4-fold. Pseudo-first-order rate constantfor the reaction of water with
2 is ~2 × 10
3-fold smaller than the first-order rate constant (0.10 s
-1) forpH-independent hydrolysis of
1 within the pH range of 9.60-10.10. Second-order rate constants (
kOH)for hydroxide ion-assisted hydrolysis of ionized
1 and
2 are 3.0 and 29.1 M
-1 s
-1, respectively. Thesolvent deuterium kinetic isotope effect (dKIE) on the rate of alk
aline hydrolysis of
1 and
2 reveals thatthe respective values of
kOH/
kOD are 0.84 and 0.78, where
kOD represents the second-order rate constantfor DO
--assisted cleavage of these imides (
1 and
2). The value of
kwH2O/
kdD2O is 2.04, with
kwH2O and
kdD2O representing pseudo-first-order rate constants for the reactions of ionized
1 with H
2O and D
2O,respectively.
