Guaiacol

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Guaiacol
IUPAC name	2-methoxyphenol
Identifiers
CAS number	[90-05-1]
PubChem	460
SMILES	COC1=CC=CC=C1O
Properties
Molecular formula	C7H8O2
Molar mass	124.137
Density	1.112 g/cm3, liquid 1.129 g/cm3, crystals
Melting point	28 °C
Boiling point	204-206 °C
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Guaiacol is a naturally occurring organic compound with the formula C₆H₄(OH)(OCH₃). This colourless aromatic oil is derived from guaiacum or wood creosote. Samples darken upon exposure to air and light. Guaiacol is present in wood smoke, resulting from the pyrolysis of lignin.

Contents 1 Preparation and derivatives 2 Uses 3 References 4 See also

[edit] Preparation and derivatives

Guaiacol is obtained directly from beechwood tar. It is produced industrially from pyrocatechin by methylation with potash and potassium methyl sulfate, or from anisole by nitration, reduction of the resulting ortho-nitroanisole to 2-aminoanisole, which is then diazotized and boiled with water.^{[citation needed]} In the laboratory, it can be synthesized by the di-methylation of catechol followed by selective mono-demethylation.^[1]

C₆H₄(OH)₂ + 2 (CH₃O)₂SO₂ → C₆H₄(OCH₃)₂ + 2 HO(CH₃O)SO₂

C₆H₄(OCH₃)₂ + C₂H₅SNa → C₆H₄(OCH₃)(OH)

Guaiacol carbonate is known as duotal, the phosphate as phosphatol, the phosphite as guaiaco-phosphal; phosphotal is a mixture of the phosphites of creosote phenols.^{[citation needed]} The valerianic ester of guaiacol is known as geosote, the benzoic as benzosol, the salicylic as guaiacolsalol, while the glycerin ether appears as guaiamar.

[edit] Uses

Guaiacol is used medicinally as an expectorant, antiseptic, and local anesthetic. Guaiacol is also used in the preparation of eugenol^[2] and vanillin^[3]. The related derivative, dimethoxybenzene or veratrol, is also used in medicine.

Because of its natural color changing abilities, it is sometimes used as an indicator solution in various experiments involving enzymes.

[edit] References

1. ^ R. N. Mirrington and G. I. Feutrill “Orcinol Monomethyl Ether” Organic Syntheses, Collected Volume 6, p.859 (1988). http://www.orgsyn.org/orgsyn/pdfs/CV6P0859.pdf
2. ^ C. F. H. Allen and J. W. Gates, Jr. “o-Eugenol” Organic Syntheses, Collected Volume 3, p.418 (1955).http://www.orgsyn.org/orgsyn/pdfs/CV3P0418.pdf
3. ^ Esposito, Lawrence J.; K. Formanek, G. Kientz, F. Mauger, V. Maureaux, G. Robert, and F. Truchet (1997). "Vanillin". Kirk-Othmer Encyclopedia of Chemical Technology, 4th edition 24. New York: John Wiley & Sons. 812–825. 

[edit] See also

• Merck Index, 13th Edition, 4568.