Eugenol is a colorless, oily liquid with a strong cloves odor. It turns yellow upon storage on air an light. Eugenol is almost insoluble in water, boundedly soluble in ethanol and methanol; fully miscible with propylene glycol, benzene, diethyl ether, toluene. Eugenol is a component of sertain essential oils: clove oil (~80%), east Indies basil oil (70-80%), nutmeg, cinnamon and some others.
Eugenol reacts with alkalis to form water soluble salts. This property is used for it extraction from natural essential oils. Like other phenols, it form esters when combined with carboxylic acids. These esters are widely used in perfumery. Oxidation of eugenol results in vanillin. Being heated in the presence of catalysts (alkalis or platinum on activated charcoal) eugenol isomerizes to give isoeugenol:
Eugenol shows a moderate toxisity. Overdosing may cause symptoms of blood in the urine, convulsions, diarrhea, nausea, unconsciousness, dizziness, rapid heartbeat or allergic reactions.
Eugenol is obtained by two general routes:
- by extraction from natural essential oils, which is treated with alkali water solution to form soluble salt followed by neutralization;
- by alkylation of guaiacol with allyl alcohol or allyl chloride:
- as a raw material in isoeugenol making;
- as a component in perfumery compositions itself;
- as an intermediate in fragnances manufacturing;
- for tobacco aromatization;
- as an intermediate in pharmaceutical chemistry;
- in making of stabilizers and antioxidants for plastics;
- in formulating insect attractants, UV absorbers, biocides and antiseptics;
- for the manufacture of vanillin (obsolete method);
- in dentistry in the mixture with zinc oxide has restorative and prosthodontic applications;