Pimelic acid is the organic compound with the formula HO2C(CH2)5CO2H. Pimelic acid is one CH
2
unit
longer than a related dicarboxylic acid, adipic acid, a precursor to many polyesters and polyamides. However compared to adipic acid, pimelic acid is relatively small in importance industrially.[2] Derivatives of pimelic acid are involved in the biosynthesis of the amino acid lysine and the vitamin biotin.

Pimelic acid
Skeletal formula of pimelic acid
Ball-and-stick model of the pimelic acid molecule
Names
Preferred IUPAC name
Heptanedioic acid
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
DrugBank
ECHA InfoCard 100.003.492 Edit this at Wikidata
EC Number
  • 203-840-8
UNII
  • InChI=1S/C7H12O4/c8-6(9)4-2-1-3-5-7(10)11/h1-5H2,(H,8,9)(H,10,11) ☒N
    Key: WLJVNTCWHIRURA-UHFFFAOYSA-N ☒N
  • InChI=1/C7H12O4/c8-6(9)4-2-1-3-5-7(10)11/h1-5H2,(H,8,9)(H,10,11)
    Key: WLJVNTCWHIRURA-UHFFFAOYAR
  • OC(=O)CCCCCC(=O)O
Properties
C7H12O4
Molar mass 160.17 g/mol
Appearance colorless or white solid
Density 1.28 g/cm3
Melting point 103 to 105 °C (217 to 221 °F; 376 to 378 K)
Boiling point decomposes
Acidity (pKa) 4.71 pKa2 = 5.58 [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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Synthesis

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Biosynthesis

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The biosynthesis of pimelic acid is unknown but is speculated to start with malonyl CoA.[3]

Chemical and industrial routes

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Like other simple dicarboxylic acids, many methods have been developed for producing pimelic acid. Pimelic acid is produced commercially by oxidation of cycloheptanone with dinitrogen tetroxide. Other routes include the relatively unselective oxidation of palmitic acid and the carbonylation of caprolactone.[2]

Niche methods

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Many other methods exist. Pimelic acid has been synthesized from cyclohexanone and from salicylic acid.[4] In the former route, the additional carbon is supplied by dimethyloxalate, which reacts with the enolate.

In other syntheses, pimelic acid is made from cyclohexene-4-carboxylic acid,[5] and a fourth method also exists based on the 1,4 reaction of malonate systems with acrolein.[6]

Several patents exist for the production of pimelic acid.[7][8][9][10][11][12]

See also

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References

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  1. ^ CRC Handbook of Chemistry and Physics 83rd ed. p.8-52
  2. ^ a b Cornils, Boy; Lappe, Peter (2000). "Dicarboxylic Acids, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_523. ISBN 978-3527306732.
  3. ^ Manandhar, Miglena; Cronan, John E. (2017). "Pimelic Acid, the First Precursor of the Bacillus subtilis Biotin Synthesis Pathway, Exists as the Free Acid and Is Assembled by Fatty Acid Synthesis". Molecular Microbiology. 104 (4): 595–607. doi:10.1111/mmi.13648. PMC 5426962. PMID 28196402. S2CID 13732917.
  4. ^ H. R. Snyder; L. A. Brooks; S. H. Shapiro; A. Müller (1931). "Pimelic Acid". Organic Syntheses. 11: 42. doi:10.15227/orgsyn.011.0042.
  5. ^ Werber, Frank X.; Jansen, J. E.; Gresham, T. L. (1952). "The Synthesis of Pimelic Acid from Cyclohexene-4-carboxylic Acid and its Derivatives". Journal of the American Chemical Society. 74 (2): 532. doi:10.1021/ja01122a075.
  6. ^ Warner, Donald T.; Moe, Owen A. (1952). "Synthesis of Pimelic Acid and α-Substituted Pimelic Acid and Intermediates1". Journal of the American Chemical Society. 74 (2): 371. doi:10.1021/ja01122a024.
  7. ^ U.S. patent 2,826,609
  8. ^ U.S. patent 2,800,507
  9. ^ U.S. patent 2,698,339
  10. ^ U.S. patent 3,468,927
  11. ^ U.S. patent 4,888,443
  12. ^ U.S. patent 2,673,219