Title: Pyrogallol
CAS Registry Number: 87-66-1
CAS Name: 1,2,3-Benzenetriol
Additional Names: 1,2,3-trihydroxybenzene; pyrogallic acid
Molecular Formula: C6H6O3
Molecular Weight: 126.11
Percent Composition: C 57.14%, H 4.80%, O 38.06%
Literature 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).
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).
Melting point: mp 131-133°
Boiling point: bp 309°
Density: d 1.45
Toxicity data: LD50 orally in rabbits: 1.6 g/kg (Dollahite)
Derivative Type: Monoacetate
CAS Registry Number: 1330-51-4
Trademarks: Eugallol (Knoll)
Molecular Formula: C8H8O4
Molecular Weight: 168.15
Percent Composition: 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.
Boiling point: bp23 ~185°
Derivative Type: Triacetate
CAS Registry Number: 525-52-0
Additional Names: Acetpyrogall
Trademarks: Lenigallol (Knoll)
Molecular Formula: C12H12O6
Molecular Weight: 252.22
Percent Composition: 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.
Melting point: mp 165°
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 reagent for antimony and bismuth; as an active reducer for gold, silver and mercury salts; especially for absorption of oxygen in gas analysis.
Therap-Cat: Has been used as antipsoriatic.
Keywords: Antipsoriatic.
Pyrolan Pyroligneous Acid Pyromellitic Acid Pyronaridine Pyronine B

Skeletal formula
Ball-and-stick model
CAS number 87-66-1 YesY
ChemSpider 13835557 YesY
ChEBI CHEBI:16164 YesY
Jmol-3D images Image 1
Molecular formula C6H6O3
Molar mass 126.11 g/mol
Density 1.45 g/cm3
Melting point 131–134 °C
Boiling point 309 °C
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Pyrogallol is an organic compound with the formula C6H3(OH)3. It is a white solid although because of its sensitivity toward oxygen, samples are typically brownish.[1] It is one of three isomeric benzenetriols.