322. Aluminon

Nomenclature

CAS number: 569-58-4
3,3′-[(3-Carboxy-4-oxo-2,5-cyclohexadien-1-ylidene)methylene]bis[6-hydroxybenzoic acid] ammonium salt (1:3); 5-[(3-carboxy-4-hydroxyphenyl)(3-carboxy-4-oxo-2,5-cylohexadien-1-ylidene)methyl]-2-hydroxybenzoic acid triammonium salt; 3-[bis(3-carboxy-4-hydroxyphenyl)methylene]-6-oxo-1,4-cyclohexadiene-1-carboxylic acid triammonium salt; ammonium salt of aurintricarboxylic acid; Lysofon (Lafon).
C22H23N3O9; mol wt 473.43.
C 55.81%, H 4.90%, N 8.88%, O 30.42%.

Description and references

Prepd by reacting sodium nitrite with salicylic acid and adding formaldehyde, then treating with ammonia: G. B. Heisig, W. M. Lauer, Org. Synth. coll. vol. I, 54 (2nd ed., 1941).

Chemical structure

Properties

Yellowish-brown, glassy powder. Freely sol in water.

Use

Forms brilliantly colored lakes with aluminum, chromium, iron, beryllium. Generally used for the detection and colorimetric estimation of aluminum in water, foods, tissues. Cf. Scherrer, Mogerman, J. Res. Natl. Bur. Stand. 21, 105 (1938).

Therapeutic Category

Pharyngeal aerosol spray.