3-Amino-4-methoxybenzenesulfonic acid diazo, in alkaline conditions and 4-Hydroxy-6-(phenylamino)naphthalene-2-sulfonic acid?coupling, and then in the copper sulfate ammonia solution in heating, in 70 ℃ keep 45 minutes, make its formation copper complex. In the complex process medium armor oxygen radicals were hydroxyl replaced.
Properties and Applications
Dark brown. Soluble in water for red light brown, in very low solubility in ethanol. The strong sulfuric acid to red light purple, diluted for brown. Adding strong hydrochloric acid in aqueous solution with brown precipitation; Add thick sodium hydroxide solution for red wine.