3,3′-Dimethoxylbenzidine double nitriding, first in alkaline conditions and 8-Amino-4-hydroxynaphthalene-2-sulfonic acid, and then matches with 4-Hydroxynaphthalene-1-sulfonic acid coupling.
Properties and Applications
blue. Soluble in water for purple to red light blue. The strong sulfuric acid for green light blue, diluted into a red light purple; In nitric acid to yellow. The dye solution to join strong hydrochloric acid for blue purple; Add thick sodium hydroxide solution for purplish red color to red light purple.
