3,3′-Dimethylbenzidine double nitriding, first with 8-Aminonaphthalene-2-sulfonic acid coupling, product to diazo, and 4,5Dihydroxynaphthalene-1-sulfonic acid (2 Moore) coupled.
Properties and Applications
black. Soluble in water for dark purple, soluble in ethanol. The strong sulfuric acid for blue, shallow purple for diluted. The dye solution to join strong hydrochloric acid have dark purple precipitation; Add thick sodium hydroxide solution have dark purple precipitation.