5-Amino-2-(4-aminophenylamino)benzenesulfonic acid double nitriding, in alkaline conditions and 4-Amino-5-hydroxynaphthalene-1-sulfonic acid coupling, 2-Aminobenzenesulfonic acid diazo, in alkaline conditions and 4-Amino-5-hydroxynaphthalene-1-sulfonic acid group of adjacent a coupling, and then and Resorcinol coupling.
