Selectivity in the N- and/or C-alkylation of schiff bases catalyzed by crown ether.

The reaction of anions derived from Schiff bases (N-(α-methylbenzylidene)aniline and N-cyclohexylideneaniline) with ethyl iodide or diethyl sulfate in aprotic solvents, in the presence of 18-crown-6, is found to give a high ratio of N⁄(N+C) or C⁄(N+C) alkylation when conducted in benzene or in dioxane.