Kinetic studies on the imines derived from reaction of 2-Amino-2-hydroxymethylpropane-1,3-diol with 2-Hydroxybenzaldehyde and with 1-Hydroxy-2-naphthaldehyde. Hydrolysis kinetics, and evidence for catalysis by the phenolate (ortho-O^-) group in the imine formation reaction

Abstract

pH-rate profiles are reported for the hydrolysis of 2-[[{2-hydroxy-1,1-di(hydroxymethyl)ethyl}-imino]methyl]phenol (1) and 1-[[{2-hydroxy-1,1-di(hydroxymethyl)ethyl}imino]methyl]-2-naphthol (2). Rate coefficients for possible contributing reactions are established and compared. Measurement of the rate of hydrolysis in deuterium oxide of (1) in the neutral plateau region of the pH-rate profile shows that the imine (1) is about 1.6 times more reactive in H₂O than in D₂O, and possible contributing factors to this solvent isotope effect are considered.

Also reported are rate data for formation of (1) from 2-amino-2-hydroxymethylpropane-1,3-diol and 2-hydroxybenzaldehyde which show the latter to be almost as reactive in the anionic as in the neutral form; this suggests a base catalysis role by the phenolate oxygen in imine formation.