Condensations of 1,4-Cyclohexanediones and Secondary Aromatic Amines. II. N-Phenylation of Diarylamines

Article abstract of DOI:10.1246/bcsj.59.803

The condensations of 1,4-cyclohexanedione with several diphenylamines were investigated in order to determine the limit of the utility of this reaction for the N-phenylation of aromatic secondary amines. 4-Methoxy-, 4,4'-dimethyl-, and 4,4'-dibromodiphenylamines produced their N-phenylated compounds in fairly good yields, but 4-hydroxy-, 3-methoxy-, and 4,4'-bis(dimethylamino)diphenylamines produced poor yields.Nitro-substituted diphenylamines gave N-phenyl derivatives in low yields along with N-4-hydroxyphenyl derivatives.N,N'-Diphenyl-p-phenylenediamine and N,N'-diphenylbenzidine gave correspondig tetra-N-phenyl diamines in good yields.The condensation of N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, di-2-pyridylamine, phenothiazine, and carbazole with 1,4-cyclohexanedione were also examined.