Aniline nuclear alkylation

In me instances, an aj tyl bound to nitrogen or to oxygen may wander to the nucelus. For exawpt, aniline is converted to dimethylaniline by beating to about 205°C with methanol and a small amount of sulfuric acid if the temperature is raised to 250-300 C, considerable nuclear alkylation takes place, the reatsribfi probably being as follows ... 

The reduction of N-alkyl- -nitroanilines to the corresponding cyclo-hexanediamines has been carried out with hydrogen over cobalt-on-alumina and ruthenium catalysts. Sometimes a nuclear-substituted aniline is acetylated before reduction in order to avoid side reactions. Thus, catalytic hydrogenation of p-acetaminophenol and ethyl p-acetaminophenyl-acetate has been successfully accomplished with platinum catalyst at 50-60° in the presence of acetic acid. 

In acid solution aromatic amines form resins with formaldehyde. This reaction in olves the formation of nuclear methylene linkages similar to those which occur in phenol-formaldehyde resins. The reaction type characteristic of the aromatic nucleus rather than of the activating amine group, whose presence merely facilitates reaction. As a result, resins can be obtained even with tertiary amines such as dimethylaniline. Under these conditions the amine reacts as an ammono-phenol. Studies of the mechanism by which formaldehyde reacU with X-alkyl anilines in acid elution indicate that the primary reaction involves the nitrogen atom. 

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