Title: Croceic Acid
CAS Registry Number: 132-57-0
CAS Name: 7-Hydroxy-1-naphthalenesulfonic acid
Additional Names: 2-naphthol-8-sulfonic acid; Bayer's acid
Molecular Formula: C10H8O4S
Molecular Weight: 224.23
Percent Composition: C 53.56%, H 3.60%, O 28.54%, S 14.30%
Literature References: Prepn: Nietzki, Zübelen, Ber. 22, 453 (1889); Forster, Keyworth, J. Soc. Chem. Ind. London 46, 26T (1927).
Properties: On evaporation of an aq soln, the free acid dec into sulfuric acid and b-naphthol. However, very concd solns of the acid can be obtained. The normal sodium salt is sol in water, and readily sol in alcohol, crystallizing with 2 mols of alcohol. Ref: Forster, Keyworth, loc. cit.