Guaiacol is an agent believed to have antiseptic properties and is used as an expectorant. Guaiacol is a phenolic natural product originally isolated from the oxidation of guaiac resin and lignin. Guaiacol is also found in wood smoke as a product of pyrolysis of lignin. Guaiacol has also been found in the urine of patients with neuroblastoma and pheochromocytoma.

Figure 1. Guaiacol

Uses

It is used medically as an expectorant, antiseptic, and local anesthetic. Guaiacol is used in traditional endodontic sedation and has the property of inducing cell proliferation; guaiacol is an effective scavenger of reactive oxygen radicals, and its free radical scavenging activity may be related to its effect on cell proliferation.

Preparation

In nature, guaiacol is found in guaiac resin or pine oil. Creosote oil obtained by wood distillation is mainly composed of guaiacol, and creosote oil can be obtained by fractionating creosote oil. Osaka Fine Chemicals Co., Ltd. in Japan uses o-nitrochlorobenzene as raw material to produce o-nitroanisole, which is then reduced to o-aminoanisole to finally obtain this product. The production method in my country is roughly the same. Raw material consumption quota: contains 1250kg/t of aminoanisole, 1500kg/t of sulfuric acid (93%), 700kg/t of sodium nitrite, and 400kg/t of copper sulfate. The methylation method of catechol is commonly used in industry to produce guaiacol.

For example, potassium carbonate reacts with dimethyl sulfate and catechol:

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

Guaiacol can also be obtained by distilling wood creosote to obtain its mixture.

Related compounds

The ether formed by guaiacol and glycerol (guaifenesin) is a commonly used expectorant, also known as grease or cough syrup. Another derivative of guaiacol, dimethyl ether (also known as resveratrol or resveratrol), is also a commonly used chemical product.

Safety

Guaiacol can be used as an indicator of smoke inhalation because the amount of guaiacol ingested from food is much greater than the amount of smoke inhaled through breathing.