2-(2, 6-Diaminophenyl) ethanol can be conducted to 4-hydroxyindoline under heating in aqueous 70% phosphoric acid, and to 4-aminoindoline under heating in aqueous 30% sulfuric acid. Both 4-hydroxy-and 4-aminoindoles were obtained by dehydrogenation of the indolines under refluxing in 1, 4-dimethylbenzene over palladium on charcoal.
