3,3′-Dimethoxylbenzidine double nitriding, in alkaline conditions and 4-Amino-5-hydroxynaphthalene-2,7-disulfonic acid, and then three with Benzene-1,3-diamine coupling, N-(4-aminophenyl)acetamide diazo, and formation of accidentally coupled nitrogen compounds.
Properties and Applications
blue and black. Moderate soluble in water (for violet black) and ethanol (for dark purple). The strong sulfuric acid for Gray light black, diluted for dark purple. The dye solution to join strong hydrochloric acid have dark purple precipitation; Add thick sodium hydroxide solution have sauce red precipitate.