Enhancement of the Rate of Mannich Reactions in Aqueous Media

The rate of Mannich reaction of phenols and of ketones with secondary amines is greatly increased in aqueous compared with alcoholic or hydrocarbon solvents. Two phase systems are present and a phase transfer catalysis may be operative. With phenols and excess co-reactants the products are mono- or isomeric disubstituted dialkylaminomethyl derivatives dependent upon the reaction time.