3564-26-9

3-Amino-4-hydroxybenzenesulfonic acid diazotization, and Resorcinol coupling.

dark red to bordeaux. Soluble in water for orange to brown light orange, slightly soluble in ethanol for yellow orange, soluble in Acetone. In concentrated sulfuric acid to red light yellow, dilute color shallow; In concentrated nitric acid for orange brown solution.

Standard	Ironing Fastness	Light Fastness	Fulling		Persperation Fastness	Soaping	Water
			Alkali	Acid
ISO	2-3	5	3-4	3	4	4	5
AATCC	4-5	5	4-5		4-5	4-5	5

Purify the dye by precipitating the free acid from aqueous solution using concentrated HCl, then wash it and extract it with EtOH in a Soxhlet extractor. Evaporation of the EtOH leaves the purified acid which is converted to the sodium salt.