DEALKYLATION OF N,N-DIALKYLANILINES OVER TRANSITION-METAL CATALYSTS IN THE PRESENCE OF AMMONIA, WATER AND HYDROGEN

The dealkylation of N,N-dimethyl- and N,N-diethylanilines over transit ion metal catalysts (Pd, Pt, Ru, and Rh) supported on charcoal was enh anced by the presence of ammonia, water, and hydrogen. Among these met als, the palladium catalyst was the most effective for dealkylation wh ich formed aniline, i.e., the fission of alkyl groups occurred by step wise degradation of the C-N bond. The C-N bond of N,N-dialkylaniline w as considered to dehydrogenate to the iminium cation on a palladium ca talyst, and subsequent hydrolysis of the iminium cation gave aldehyde and N-alkylaniline. The dehydrogenation of the C-N bond of N-alkylanil ine similarly occurred to yield benzoimine, and the corresponding hydr olysis of imine gave aniline and aldehyde.