Reactivity of o-aminomethylphenols in the Menshutkin reaction

Abstract

1. The kinetics of the reaction of o-aminomethylphenols and dimethylbenzylamine with alkyl halides have been studied. The rate of quaternization of the amino group depends on the steric conditions in the nucleophilic and electrophilic reagents, the basicity of the nucleophile, the length and degree of branching of the hydrocarbon chains in the alkyl halides, and on the presence of an intramolecular hydrogen bond (IHB) between the amino nitrogen atom and the phenolic hydroxyl group. 2. The sharp decrease in the reactivity of the o-aminomethylphenols compared with the benzylamine in protonic dipolar solvents is due to an increase in the strength of the IHB in these media. 3. Compared with aprotic dipolar solvents, the reactivity of o-dimethylaminomethylphenol in alcohols is increased due to weakening of the IHB. Dimethylbenzylamine has low reactivity in alcohols due to its specific solvation by alcohols.