A Phenylglycolic acid

Mandelic acid with a 13 - 20 % enantiomeric excess of the (R)-isomer has been obtained from reduction of phenylglycolic acid in aqueous alcohol buffers containing strychnine in low concentration. The optical yield depends upon pH and is highest (20 - 24 %) at pH 0 or 9.2 and at low current density. In the pH range 2-4, the optical yield drops to 2-8% [42]. The higher result compares well with the maximum value of 20% excess R-isomer found from reduction of (-)-menthyl phenylglycolate in aqueous buffers where the (-)-menthyl ester is the only chiral reagent present [43 ]. 

Rule-based or systematic nomenclature (e.g., International Union of Pure and Applied Chemistry [IUPAC] or CAS nomenclature) is based on a set of linguistic rules that apply to its structure. For example, the IUPAC and CAS names for mandelic acid are 2-phenyl-2-hydroxyacetic acid and benzeneacetic acid, a-hydroxy-, respectively. The number of possible systematic names is practically endless. A small, but not nearly exhaustive, set of other systematic names includes phenylglycolic acid, phe-nylhydroxyacetic acid, ( )-a-hydroxybenzeneacetic acid, ( )-a-hydroxyphenylacetic acid, ( )-2-hydroxy-2-phenylethanoic acid, ( )-Mandelic acid, (RS)-Mandelic acid, DL-Amygdalicacid,DL-Hydroxy(phenyl)aceticacid,DL-mandelicacid,paramandelic acid, a-hydroxy- a-toluic acid, a-hydroxyphenylacetic acid, a-hydroxybenzeneacetic... 

S)-Mandelic (1) and (/ )-mandelic acid (2) are the more familiar names for the chiral antipodes of a-hydroxybenzeneacetic acid, also known as phenylglycolic acid or amygdalic acid. As orthorhombic plates from water, pure mandelic acid melts at 119 °C and has a Ks = 43 X 10 " M. Mandelic acid is moderately soluble in water (1 g to 6.3 mL water) and very soluble in ether and isopropanol. Therapeutically, mandelic acid is most commonly used as a urinary antiseptic [1]. 

Synonyms Amygdalic acid Amygdalinic acid Benzoglycolic acid Glycolic acid, phenyl- a-Hydroxyphenylacetic acid o-Hydroxy-a-toluic acid DL-Mandelic acid L-Mandelic acid Paramandelic acid Phenylglycolic acid... 

Phenylglycollic acid Phenylglyconic acid Phenylhydroxyacetic acid a-Phenylhydroxyacetic acid Racemic mandelic acid... 

Hydroiqrnumdelic Acid 3-Hydroxy phenylglycollic acid, Z-a-dihydroxypkenylacetic acid, Z-a-dihydroxy-a-tolme acid). 

Synonyms a-Hydroxybenzeneacetic acid -hydroxy-oetoluic acid a -hydroxy phenylacetic acid phenylhydroxyacetic acid phenylglycolic acid amylgdalic acid amygdalinic acid paramandelic acid Trade names Camdelate, Uromaline... 

In addition to the compounds listed in Table I, corresponding basic derivatives of the following acids have been reported crotonic isocrotonic levulinic succinic cyano-acetic mono-, di-, and trichloroacetic monobromoacetic monochloro- and monobromopropionic lactic glycolic ethyl- and phenylglycolic (a-hydroxybutyric and mandelic, respectively) and salicylic. Confirmatory evidence for the identities of most of these is completely lacking. 

Plasma DjffH activity can be low to undetectable in normal individuals, therefore a low value is not diagnostic by itself. 30MD, 3-0-methyldopa HVA, homovanillic acid MHPG, 3-methoxy-4-hydroxy-phenylglycol VMA, vanillylmandelic acid. 

A large number of studies have been carried out on this subject in connection with the production of plastics. As mentioned earlier benzoic acid, mandelic acid, phenylglycol and phenyl glyoxylic acid are formed [195, 197] (Fig. 8). 

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