Mechanism of Hydrolysis of O-Imidomethyl Derivatives of Phenols

Article abstract of DOI:10.1021/jo00070a029

Three series of O-imidomethyl derivatives of para-substituted phenolic compounds were synthesized and their rates of hydrolysis were studied.Saccharin, phthalimide, and succinimide served as the imide portions of the derivatives.Their rates of hydrolysis were found to be first order with respect to hydroxide from pH 7.0 to 10 or 11 and dependent on the acidity (leaving group potential) of both the imide and the phenol portions.The more acidic the imide or the phenol, the faster the rate of hydrolysis.However, the rates of hydrolysis were more sensitive to the acidity of the phenol.Trapping experiments with cyanide also suggested that the phenol anion was functioning as the leaving group in what is apparently an S_N2 reaction.An amide derivative was found to hydrolyze more slowly than predicted from the analogous series and the pK_a of the amide.This result is apparently due partially stereoelectronic constraints in the imide series that cause the CH2-O bond to be oriented more nearly perpendicular to the plane of the C(=O)N group and hence more accessible to nucleophilic attack.