Preparation
4-Nitrobenzenamine diazo, and 2-Amino-4-methylanisole matches, will the nitro reduction for amino, product double nitriding, first and 5-Aminonaphthalene-2-sulfonic acid and 8-Aminonaphthalene-2-sulfonic acid coupling, and then in alkaline conditions and 6-Amino-4-hydroxynaphthalene-2-sulfonic acid? coupling.