Preparation
2-Amino-5-(4-amino-3-barboxyphenyl)benzoic acid?double nitriding, first coupled with 2-Hydroxybenzoic acid, again in alkaline conditions and 6-Amino-4-hydroxynaphthalene-2-sulfonic acid? coupling.
Properties and Applications
black light brown. Soluble in water for purplish red, slightly soluble in alcohol. The strong sulfuric acid for purple, diluted for Light red orange time The dye solution to join strong hydrochloric acid for red sauce, precipitation; Add thick sodium hydroxide solution for orange brown..
