1-Naphthalenesulfonic acid, 4-hydroxy-3-[(2,3,5-trichloro-6-hydroxyphenyl)azo]-, monosodium salt

2-Amino-3,4,6-trichlorophenol diazotization, and 4-Hydroxynaphthalene-1-sulfonic acid coupling.

dark purple. Soluble in water for red light purple, right amount soluble in alcohol is purple, insoluble in benzene. In concentrated sulfuric acid for black light green, dilution have orange red precipitation; Slightly soluble in concentrated nitric acid for yellow brown; In a dilute sodium hydroxide solution for yellow red.

Standard	Ironing Fastness	Light Fastness	Fulling		Persperation Fastness	Soaping	Water
			Alkali	Acid
ISO	3-4	6	4-5	4	5	5	5