8000. Pyrogallol

Nomenclature

CAS number: 87-66-1
1,2,3-Benzenetriol; 1,2,3-trihydroxybenzene; pyrogallic acid.
C6H6O3; mol wt 126.11.
C 57.14%, H 4.80%, O 38.06%.

Description and references

Observed by Scheele in 1786; prepd by Braconot in 1818. Prepn from gallic acid: Marsh, GB 144897 (1919); Rinderknecht, Niemann, J. Am. Chem. Soc. 70, 2605 (1948); from p-tert-butylphenol: Stevens, US 2603662 (1952 to Gulf). Synthesis from aliphatic sources: Shipchandler et al., J. Chem. Soc. Perkin Trans. 1 1975, 1400. Isoln from Penicillium patulum: Tanenbaum, Bassett, Biochim. Biophys. Acta 28, 21 (1958). Acute toxicity: J. W. Dollahite et al., Am. J. Vet. Res. 23, 1264 (1962).

Chemical structure

Properties

White, odorless crystals, mp 131-133°. Becomes grayish on exposure to air and light. Poisonous. d 1.45; bp 309°. Sublimes when slowly heated. One gram dissolves in 1.7 ml water, 1.3 ml alc, 1.6 ml ether; slightly sol in benzene, chloroform, carbon disulfide. The aq soln darkens on exposure to air, quite rapidly when alkaline. Keep well closed and protected from light. Incompat. Alkalies, ammonium hydroxide, antipyrine, camphor, phenol, menthol. LD50 orally in rabbits: 1.6 g/kg (Dollahite).

Derivative

Monoacetate.

Nomenclature

CAS number: 1330-51-4
Eugallol (Knoll).
C8H8O4; mol wt 168.15.
C 57.14%, H 4.80%, O 38.06%.

Properties

White or brownish liquid, bp23 ≈185°. Sol in water, alcohol, chloroform, ether, acetone and castor oil. Marketed as a 67% soln in acetone.

Derivative

Triacetate.

Nomenclature

CAS number: 525-52-0
Acetpyrogall; Lenigallol (Knoll).
C12H12O6; mol wt 252.22.
C 57.14%, H 4.80%, O 38.06%.

Properties

White, crystalline powder, mp 165°. Slightly sol in water; sol in alcohol. Dec by alkali hydroxide solns.

Caution

Potential symptoms of overexposure are vomiting, hypothermia, fine tremors, weakness, muscle incoordination, diarrhea, loss of reflexes, coma, asphyxia. Direct contact may cause skin irritation and sensitization. See Patty's Industrial Hygiene and Toxicology Vol. 2B, G. D. Clayton, F. E. Clayton, Eds. (Wiley Interscience, New York, 4th ed., 1994) p 1595-1597.

Use

Developer in photography; making colloidal solns of metals; as mordant for wool, staining leather, process engraving; manuf various dyes; dyeing furs, hair, etc. In analytical chemistry as a complexing agent; reducing agent; alkaline soln as an indicator of gaseous oxygen.