Picolinic acid is an organic compound with the formula NC5H4CO2H. It is a derivative of pyridine with a carboxylic acid (COOH) substituent at the 2-position. It is an isomer of nicotinic acid and isonicotinic acid, which have the carboxyl side chain at the 3- and 4-positions, respectively. It is a white solid although impure samples can appear tan. The compoundthat is soluble in water.
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| Names | |
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| Preferred IUPAC name
Pyridine-2-carboxylic acid | |
| Other names
Picolinic acid
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.002.472 |
PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| C6H5NO2 | |
| Molar mass | 123.111 g·mol−1 |
| Appearance | White solid |
| Density | 1.526 g/cm³ |
| Melting point | 136 to 138 °C (277 to 280 °F; 409 to 411 K) |
| Slightly soluble (0.41%) in water[1] | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Production
editOn a commercial scale, picolinic acid is produced by ammoxidation of 2-picoline followed by hydrolysis of the resulting nitrile:
- NC5H4CH3 1.5 O2 NH3 → NC5H4C≡N 3 H2O
- NC5H4C≡N 2 H2O → NC5H4CO2H NH3
It is also produced by oxidation of picoline with nitric acid.[2]
In the laboratory, picolinic acid is formed from 2-methylpyridine by oxidation with potassium permanganate (KMnO4).[3][4]
Reactions
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Hydrogenation of picolinic acid gives piperidine-2-carboxylic acid, a precursor to the drug Mepivacaine.
Picolinic acid is a bidentate chelating agent of elements such as chromium, zinc, manganese, copper, iron, and molybdenum in the human body.[5][6]
It is a substrate in the Mitsunobu reaction. In the Hammick reaction, picolinic acid reacts with ketones to give pyridine-2-carbonols:[7]
- NC5H4CO2H R2C=O → NC5H4CR2(OH) CO2
Biosynthesis
editPicolinic acid is a catabolite of the amino acid tryptophan through the kynurenine pathway.[8] Its function is unclear, but it has been implicated in a variety of neuroprotective, immunological, and anti-proliferative effects. In addition, it is suggested to assist in the absorption of zinc(II) ions and other divalent or trivalent ions through the small intestine.[9]
Picolinates
editSalts of picolinic acid (picolinates) include:
See also
editReferences
edit- ^ Lide, DR. "CRC Handbook of Chemistry and Physics, Internet Version 2005, http://hbcpnetbase.com, CRC Press, Boca Raton, Florida, 2005".
{{cite journal}}: Cite journal requires|journal=(help) - ^ Shimizu, Shinkichi; Watanabe, Nanao; Kataoka, Toshiaki; Shoji, Takayuki; Abe, Nobuyuki; Morishita, Sinji; Ichimura, Hisao (2007). "Pyridine and Pyridine Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_399. ISBN 978-3527306732.
- ^ Singer, Alvin W.; McElvain, S. M. (1940). "Picolinic Acid Hydrochloride". Organic Syntheses. 20: 79. doi:10.15227/orgsyn.020.0079.
- ^ Harold Hart, Leslie E. Craine, David J. Hart, Christopher M. Hadad; Nicole Kindler (2007). 'Organische Chemie 3. Auflage. Weinheim: Wiley-VCH. p. 494. ISBN 978-3-527-31801-8.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ Lumme, Paavo; Lundgren, Georg; Mark, Wanda; Lundström, Hans; Borch, Gunner; Craig, J. Cymerman (1969). "The Crystal Structure of Zinc Picolinate Tetrahydrate, Zn(C6H4O2N)2(H2O)4". Acta Chemica Scandinavica. 23: 3011–3022. doi:10.3891/acta.chem.scand.23-3011.
- ^ Daugulis, Olafs; Roane, James; Tran, Ly Dieu (2015). "Bidentate, Monoanionic Auxiliary-Directed Functionalization of Carbon–Hydrogen Bonds". Accounts of Chemical Research. 48 (4): 1053–1064. doi:10.1021/ar5004626. PMC 4406856. PMID 25756616.
- ^ Fuchs, Philip L. (29 July 2013). "Picolinic acid". Catalytic Oxidation Reagents. Wiley Inc. p. 495ff. ISBN 9781118704844. OCLC 954583821.
- ^ Tan, L.; et al. (December 2012). "The kynurenine pathway in neurodegenerative diseases: mechanistic and therapeutic considerations". J Neurol Sci. 323 (1–2): 1–8. doi:10.1016/j.jns.2012.08.005. PMID 22939820. S2CID 6061945.
- ^ Evans, Gary (1982). "The Role of Picolinic Acid in Metal Metabolism". Life Chemistry Reports. 1. Harwood Academic Publishers: 57–67. Archived from the original on 26 January 2016. Retrieved 20 March 2015.