3-Amino-4-hydroxybenzenesulfonic acid?diazo, in alkaline conditions and 4-Hydroxy-7-(phenylamino)naphthalene-2-sulfonic acid coupling, and then into copper complex.
Properties and Applications
purple. Soluble in water, slightly soluble in alcohol. In strong hydrochloric acid for big red; In the thick of sodium hydroxide solution for orange.
