N,N’-bis(3-aminophenyl)urea?double nitriding, first and 2,4-Diaminobenzenesulfonic acid coupling, again with Resorcinol coupling.
Properties and Applications
brown. Slightly soluble in water for yellow brown, slightly soluble in alcohol. The strong sulfuric acid in red orange for brown, diluted yellow brown to orange for brown. The dye solution was added concentrated hydrochloric acid with red brown precipitate; Add thick sodium hydroxide solution for yellow brown to orange brown; Sodium hydroxide solution to dilute the same color.
