4-Amino-3-[(4-amino-2-nitrophenyl)azo]-5-hydroxy-2,7-naphthalenedisulfonic acid disodium salt

N-(4-amino-3-nitrophenyl)acetamide?diazo, and 4-Amino-5-hydroxynaphthalene-2,7-disulfonic acid?in acid conditions coupled, then acetaminophen hydrolysis.

navy blue. Soluble in water for dark purple, slightly soluble in alcohol in deep navy blue. In the dark for the strong sulfuric acid, diluted in red. In water solution to join strong hydrochloric acid into red; With strong sodium hydroxide solution into a navy blue.

Standard	Light Fastness	Soaping		Persperation Fastness	Oxygen bleaching		Fastness to seawater
		Fading	Stain		Fading	Stain	Fading	Stain
ISO	3	2-3	2-3	3-4	3		3-4