High-pressure alkylation of bis(benzylidene)phenylenediamines

The reactions of alkyl chlorides with bisanils (obtained from o-, m-, and p-phenylenediamines) under high pressure (10 kbar) were studied. Depending on the structure of the starting diamines and the solvent nature, hydrolysis of the reaction mixtures gave pure N-monoalkyl- or N,N"-dialkylphenylenediamines in high yields. The effect of the phase transition of the solvent on the direction of alkylation is discussed.