454. 1-Amino-2-naphthol-4-sulfonic Acid

Nomenclature

CAS number: 116-63-2
4-Amino-3-hydroxy-1-naphthalenesulfonic acid; 1,2,4-acid.
C10H9NO4S; mol wt 239.25.
C 50.20%, H 3.79%, N 5.85%, O 26.75%, S 13.40%.

Description and references

Prepn: M. Schmidt, J. Prakt. Chem. Chem.-Ztg. 44, 513 (1891); by treatment of nitroso-β-naphthol with sodium bisulfite and sulfuric acid: L. F. Fieser, Org. Synth. coll. vol. II, 42 (1943); cf. idem, J. Am. Chem. Soc. 57, 494 (1935).

Chemical structure

Properties

White or gray needles, usually contg 0.5 H2O. May turn pink on exposure to light, especially when moist. Insol in water, alcohol, ether, benzene; sol in hot sodium bisulfite soln; sol in alkaline soln but such solns oxidize quickly on exposure to air yielding a brown substance which is sol in hot water giving a green soln. Controlled oxidation with HNO3 yields ammonium 1,2-naphthoquinone-4-sulfonate, see Fieser, loc. cit.

Derivative

Sodium salt.

Nomenclature

CAS number: 5959-58-0
C10H8NNaO4S; mol wt 261.23.
C 45.98%, H 3.09%, N 5.36%, Na 8.80%, O 24.50%, S 12.27%.

Properties

Needles, sol in hot water with blue fluorescence

Use

Manuf of azo dyes, 1,2-naphthoquinone-4-sulfonic acid. In determn of phosphate.