Phenylpyruvic acid

Structural formula
General
Surname	Phenylpyruvic acid
other names	2-oxo-3-phenylpropanoic acid ( IUPAC ) 2-oxo-3-phenylpropionic acid Phenylpyruvate Keto-phenylpyruvate
Molecular formula	C 9 H 8 O 3
Brief description	colorless to beige powder
External identifiers / databases
CAS number 156-06-9 EC number 205-847-1 ECHA InfoCard 100.005.317 PubChem 997 ChemSpider 972 DrugBank DB03884 Wikidata Q425030
properties
Molar mass	164.16 g mol −1
Physical state	firmly
Melting point	155  ° C (polymorphic form I) 162 ° C (polymorphic form II)
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

As a derivative of pyruvic acid, phenylpyruvic acid is an α- keto acid and a breakdown product of the amino acid phenylalanine .

Manufacture and extraction

A technical synthesis of phenylpyruvic acid starts from benzyl chloride , which is double-carbonylated using carbon monoxide and dicobalt octacarbonyl as a catalyst .

properties

Physical Properties

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

Chemical properties

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

Biological importance

Phenylpyruvic acid is excreted in the urine in high concentrations in the congenital metabolic disorder phenylketonuria . If iron (III) chloride is added to the acid in the Fölling sample , a characteristic green color appears.

Individual evidence

1. ↑ ^{a b c} Datasheet Phenylpyruvic acid, 98% from Sigma-Aldrich , accessed on December 27, 2019 ( PDF ).
2. ↑ ^{a b c} Ho-Hi Lee, Kouji Kimura, Takatomo Takai, Hitoshi Senda, Akio Kuwae, Kazuhiko Hanai: Polymorphism of phenylpyruvic acid studied by IR, Raman and solid state 13C NMR spectroscopy. In: Spectrochim. Acta A. 55, (1999), pp. 2877-2882, doi : 10.1016 / S1386-1425 (99) 00109-2 .
3. ↑ W. Bertleff, M. Roeper, X. Sava: Carbonylation in: Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH, Weinheim 2007, doi : 10.1002 / 14356007.a05_217.pub2 .
4. ↑ Kazuhiko Hanai, Akio Kuwae, Satoshi Kawai, Yoko Ono: Keto-enol tautomerism and vibrational spectra of phenylpyruvic acids. In: J. Phys. Chem. . 93 (1989), pp. 6013-6016, doi : 10.1021 / j100353a016 .
5. ↑ Kazuhiko Hanai, Satoshi Kawai: Vibrational and NMR spectra of phenylpyruvic acid and its salts in aqueous solution. In: J. Mol. Struct. . 245 (1991), pp. 21-27, doi : 10.1016 / 0022-2860 (91) 87003-Z .
6. ↑ N. Kishoref, MJ Holden, JB Tewari, RN Goldberg: A thermodynamic investigation of some reactions involving prephenic acid. In: J. Chem. Thermodyn. 31 (1999), pp. 211-227, doi : 10.1006 / jcht.1998.0444 .
7. ↑ Hiroshi Yanagawa, Yumiko Makino, Kazuki Sato, Masato Nishizawa, Fujio Egami: Novel formation of α-amino acid from α-oxo acids and ammonia in an aqueous medium. In: Origins of Life and Evolution of Biospheres. 14 (1984), pp. 163-169, doi : 10.1007 / BF00933654 .
8. ↑ Yasuhisa Asano: Enzymatic Synthesis of ( S ) -Phenylalanine and Related ( S ) -Amino Acids by Phenylalanine Dehydrogenase. In: JL Barredo (Ed.): Methods in Biotechnology. Vol. 17: Microbial Enzymes and Biotransformations. Humana Press, Totowa, NJ, p. 141.
9. ↑ CT Evans, W. Peterson, C. Choma, M. Misawa: Biotransformation of phenylpyruvic acid to l-phenylalanine using a strain of Pseudomonas fluorescens ATCC 11250 with high transaminase activity. In: Applied Microbiology and Biotechnology . 26 (1987), pp. 305-312, doi : 10.1007 / BF00256659 .