Mandelic acid 3140464 222914056 2008-07-01T18:44:22Z Dr Thermo 4574314 Corrected pK valued based of CRC Hdbk Chemistry and Physics 88th ed. {{Chembox new | Reference=<ref>''[[Merck Index]]'', 11th Edition, '''5599'''.</ref> | Name = Mandelic acid | ImageFile = Mandelic acid.png | ImageSize = 120px | ImageName = | IUPACName = 2-Hydroxy-2-phenylacetic acid | OtherNames = Mandelic acid<br />Phenylglycolic acid | Section1 = {{Chembox Identifiers | CASNo = 90-64-2 | SMILES = OC(C(O)c1ccccc1)=O }} | Section2 = {{Chembox Properties | Formula = C<sub>8</sub>H<sub>8</sub>O<sub>3</sub> | MolarMass = 152.14 g/mol | Density = 1.30 g/cm<sup>3</sup> | MeltingPt = 119 °C | BoilingPt = | Solubility = 1 g per 6.3 mL | pKa = 3.37 }} }} '''Mandelic acid''' is an [[aromatic]] [[alpha hydroxy acid]] with the molecular formula C<sub>8</sub>H<sub>8</sub>O<sub>3</sub>. It is a white crystalline solid that is soluble in water and most common organic [[solvent]]s. ==Discovery and name== Mandelic acid was discovered while heating [[amygdalin]], an extract of [[bitter almond]]s, with diluted [[hydrochloric acid]]. It was first reported in 1909 by J. W. Walker and V. K. Krieble. The name is derived from the [[German language|German]] "Mandel" for "almond". ==Chemistry== It is an [[isomer]] of cresotinic acid (2-hydroxy-3-methylbenzoic acid) and oxymethylbenzoic acid (2-methoxybenzoic acid). Derivatives of mandelic acid are formed as a result of metabolism of [[adrenaline]] and [[noradrenaline]] by [[monoamine oxidase]] and [[Transferase|catechol-o-methyl transferase]]. It is also present in certain skin care products, is an intermediate molecule in the production of other biochemicals, may be used as an analytical reagent and is a precursor in the manufacture of dyes. Since the molecule contains a [[chirality (chemistry)|chiral]] carbon atom, the acid exists in either of two [[optical rotation|optically active]] forms. The [[racemic]] mixture of the two is known as ''paramandelic acid''. It may be prepared by the action of [[hydrochloric acid]] on the addition compound of [[benzaldehyde]] and [[hydrocyanic acid]], by boiling phenylchloracetic acid with alkalis, by heating benzoyl formaldehyde with alkalis or by the action of dilute alkalis on ω-dibromacetophenone. ==See also== * [[Phenylacetic acid]] * [[Vanillylmandelic acid]] ==References== <references/> *{{1911}} {{Other antibacterials}} [[Category:Hydroxy acids]] [[Category:Aromatic compounds]] [[de:Mandelsäure]] [[es:Ácido mandélico]] [[fr:Acide mandélique]] [[nl:Amandelzuur]] [[ja:マンデル酸]] [[pl:Kwas migdałowy]]