2hydroxybenzoic

2-Hydroxybenzoic acid, commonly known as salicylic acid, is an aromatic carboxylic acid with the IUPAC name 2-hydroxybenzoic acid. It is also referred to as o-hydroxybenzoic acid. Its chemical formula is C7H6O3 and its molar mass is about 138.12 g/mol. The molecule features a carboxyl group and a hydroxyl group in the ortho position on a benzene ring, which enables intramolecular hydrogen bonding. It appears as a white crystalline solid that melts around 158 °C and is sparingly soluble in water, with greater solubility in many organic solvents.

Occurrence and roles in nature: Salicylic acid occurs naturally in several plants, including willow trees, which historically gave the compound its name from the Latin salix (willow). In plants, it acts as a signaling molecule involved in defense responses and systemic acquired resistance against pathogens.

Production and uses: Industry often prepares salicylic acid by the Kolbe–Schmitt carboxylation of sodium phenoxide with carbon dioxide, followed by acidification. It can also be obtained by hydrolysis of salicylate esters or by from acetylation products related to aspirin chemistry. Major applications include serving as the precursor to acetylsalicylic acid (aspirin) and as a topical keratolytic agent in dermatology and cosmetics. It is also used in analytical chemistry and as a plant defense elicitor at low concentrations.

Safety: Salicylic acid is a mild irritant to skin and eyes. Ingestion can lead to salicylate poisoning; use in children with viral infections is approached with caution due to the risk of Reye’s syndrome. Appropriate handling and safety measures are recommended.