Kinetics and mechanism of the general base-catalyzed hydrolysis of N-hydroxyphthalimide

The kinetics and mechanism of hydrolysis of N-hydroxyphthalimide in the presence of various buffers (dichloroacetic acid, chloroacetic acid, glycine, sodium formate, sodium acetate, N-(2-morpholinoethane)sulfonic acid, and tris(hydroxymethyl)aminomethane) were studied at 50 A degrees C and an ionic strength of 1.0 M. The second-order rate constants k (b) for the buffer-catalyzed hydrolysis of N-hydroxyphthalimide were found to conform to the Bronsted equation logk (b) = C + beta pK (a). A plot of pK (a) versus k (b) for the data obtained in the buffers and H2O (covering a pK (a) range of -1.74 to 8.33) was constructed, and the data were fitted with a straight line that had a slope (beta) of 0.29 +/- A 0.05 and an intercept (C) of -5.19 +/- A 0.20.