Phenylpyruvic acid

• 2-oxo -3- phenylpropanoic acid
• 2-oxo- 3-phenylpropionic acid
• Phenylpyruvate
• Keto- phenylpyruvate

Colorless to beige powder

Fixed

Template: Infobox chemical / molecular formula search available

Phenylpyruvic acid, with IUPAC name 2-oxo -3- phenylpropanoic acid, is a derivative of pyruvic acid, an α -keto acid, and a degradation product of the amino acid phenylalanine.

Production and recovery

A technical synthesis of phenylpyruvic starts from benzyl chloride, which is carbonylated twice by carbon monoxide and dicobaltoctacarbonyl as a catalyst.

Properties

Physical Properties

The compound is a tautomeric equilibrium can be formulated with a keto- enol structure and a. In the solid phase, two polymorphic forms can occur, melting at 155 ° C ( Form I) and 162 ° C ( form II). Form II is unstable at room temperature and changes within two days in Form I to. IR and Raman spectroscopic studies showed that in both solid forms present the enol structure. In solution, the location of the Tautomeriegleichgewichts on the type of solvent depends on. While in aprotic solvents such as carbon tetrachloride and DMSO dominates the enol form, is in aqueous solution before a stabilized by hydration of the keto form. With an acidity constant pKa of 2.54 phenylpyruvic acid is a relatively strong acid.

Chemical Properties

Phenylpyruvic acid can be converted by treatment with ammonia or ammonium sulfate in an aqueous medium in racemic phenylalanine or its amide. The synthesis of the enantiomerically pure (S)- isomer or (R)- Isomersgelingt in enzymatic reactions.

Biological Significance

Phenylpyruvic acid is excreted in congenital metabolic disorder phenylketonuria in high concentrations in the urine. Priority of the acid in the sample Fölling iron ( III) chloride in occurs a characteristic green color.