2588. Croceic Acid

Nomenclature

CAS number: 132-57-0
7-Hydroxy-1-naphthalenesulfonic acid; 2-naphthol-8-sulfonic acid; Bayer's acid.
C10H8O4S; mol wt 224.23.
C 53.56%, H 3.60%, O 28.54%, S 14.30%.

Description and references

Prepn: Nietzki, Zübelen, Ber. 22, 453 (1889); Forster, Keyworth, J. Soc. Chem. Ind. London 46, 26T (1927).

Chemical structure

Properties

On evaporation of an aq soln, the free acid dec into sulfuric acid and β-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.