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Salicylic
Acid is a white crystalline powder or needle-shaped crystals with
sweetish taste; soluble in acetone, ether, alcohol, boiling water,
benzene and turpentine, sparingly soluble in chloroformbenzene, slightly
soluble in water; melts at 158°C. It is prepared commercially by sodium
salicylate, which derived from sodium phenolate with carbon dioxide under
heating and pressure. It contains both a hydroxyl and a carboxyl group,
which react with either an acid or an alcohol. The carboxyl group forms
esters with alcohols; e.g. methyl salicylate is formed with methanol,
which used in food flavorings and preservatives; methyl salicylate is
formed with methanol, which is used in suntan lotions. The hydroxyl group
reacts with acetic acid to form acetylsalicylic acid (called aspirin),
which is the most widely common antiseptic and antipyretic agent. Phenyl
salicylate (called salol) is formed with phenol, which is also used as an
antiseptic and antipyretic agent. The sodium salt (Sodium salicylate), a
shiny white powder, is used for antiseptics preparations and as a
preservative. In addition to its analgesic and antipyretic
properties, salicylic acid possesses keratinolytic properties and
fungicidal properties. It and its derivatives are used in the
treatment of hyperkeratotic, dandruff, ichthyosis and psoriasis as
well as in the treatment of fungal skin infections such as tine.
Salicylic Acid and its derivatives are important for the preparation of
other pharmaceutical products, dyes, flavors, and preservatives.
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