Chicago Acid

Name:
Chicago Acid
Detailed information:

Chemistry name:	1-amino-8-naphthol-2,4-disulfonic acid; 8-amino-1-naphthol-5,7-disulfonic acid; SS acid; 1,8,2,4-acid; 2-sulfur acid
Chemistry structure:
Properties:
Gray paste, white when pure. Soluble in water and sodium hydroxide solution.
Derivation:
1-Naphthylamine-8-sulfonic acid is reacted with sulfuric acid to yield 1-naphthylamine-4,8-disulfonic acid; further reaction with 25% oleum gives 1,8-naphthosulfam-2,4-disulfonicacid, which melts at 155C with 40% NaOH.
Use:
Azo dye intermediate.