{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 447493998 | Name = Pimelic acid | ImageFile = Heptanedioic acid 200.svg | ImageClass = skin-invert-image | ImageSize = 240 | ImageAlt = Skeletal formula of pimelic acid | ImageFile1 = Pimelic acid molecule ball from xtal.png | ImageClass1 = bg-transparent | ImageSize1 = 240 | ImageAlt1 = Ball-and-stick model of the pimelic acid molecule | PIN = Heptanedioic acid |Section1={{Chembox Identifiers | CASNo_Ref = {{cascite|correct|CAS}} | CASNo = 111-16-0 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = BZQ96WX25F | SMILES = OC(=O)CCCCCC(=O)O | EINECS = 203-840-8 | PubChem = 385 | ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}} | ChemSpiderID = 376 | InChI = 1/C7H12O4/c8-6(9)4-2-1-3-5-7(10)11/h1-5H2,(H,8,9)(H,10,11) | InChIKey = WLJVNTCWHIRURA-UHFFFAOYAR | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChI = 1S/C7H12O4/c8-6(9)4-2-1-3-5-7(10)11/h1-5H2,(H,8,9)(H,10,11) | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = WLJVNTCWHIRURA-UHFFFAOYSA-N | ChEBI_Ref = {{ebicite|changed|EBI}} | ChEBI = 30531 | DrugBank_Ref = {{drugbankcite|changed|drugbank}} | DrugBank = DB01856 }} |Section2={{Chembox Properties | Formula = C<sub>7</sub>H<sub>12</sub>O<sub>4</sub> | Appearance = colorless or white solid | MolarMass = 160.17 g/mol | Density = 1.28 g/cm<sup>3</sup> | MeltingPtC = 103 to 105 | MeltingPt_notes = | BoilingPt = decomposes | pKa = 4.71 pKa2 = 5.58 <ref>CRC Handbook of Chemistry and Physics 83rd ed. p.8-52</ref> }} }}
'''Pimelic acid''' is the organic compound with the formula HO<sub>2</sub>C(CH<sub>2</sub>)<sub>5</sub>CO<sub>2</sub>H. Pimelic acid is one {{chem|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.<ref name=Ullmann/> Derivatives of pimelic acid are involved in the biosynthesis of the amino acid lysine and the vitamin biotin.
== Synthesis == ===Biosynthesis=== The biosynthesis of pimelic acid is unknown but is speculated to start with malonyl CoA.<ref>{{cite journal |doi=10.1111/mmi.13648|title=Pimelic Acid, the First Precursor of the ''Bacillus subtilis'' Biotin Synthesis Pathway, Exists as the Free Acid and Is Assembled by Fatty Acid Synthesis|year=2017|last1=Manandhar|first1=Miglena|last2=Cronan|first2=John E.|journal=Molecular Microbiology|volume=104|issue=4|pages=595–607|pmid=28196402 |s2cid=13732917|pmc=5426962}}</ref>
===Chemical and industrial routes=== 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.<ref name=Ullmann>{{Ullmann|doi=10.1002/14356007.a08_523|chapter=Dicarboxylic Acids, Aliphatic|year=2000|last1=Cornils|first1=Boy|last2=Lappe|first2=Peter}}</ref>
====Niche methods==== Many other methods exist. Pimelic acid has been synthesized from cyclohexanone and from salicylic acid.<ref>{{cite journal|author=H. R. Snyder |author2=L. A. Brooks |author3=S. H. Shapiro |author4=A. Müller |title=Pimelic Acid|journal=Organic Syntheses|volume=11|page=42|year=1931|doi=10.15227/orgsyn.011.0042}}</ref> 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,<ref>{{cite journal|doi=10.1021/ja01122a075|title=The Synthesis of Pimelic Acid from Cyclohexene-4-carboxylic Acid and its Derivatives|journal=Journal of the American Chemical Society|volume=74|issue=2|page=532|year=1952|last1=Werber|first1=Frank X.|last2=Jansen|first2=J. E.|last3=Gresham|first3=T. L.}}</ref> and a fourth method also exists based on the 1,4 reaction of malonate systems with acrolein.<ref>{{cite journal|doi=10.1021/ja01122a024|title=Synthesis of Pimelic Acid and α-Substituted Pimelic Acid and Intermediates1|journal=Journal of the American Chemical Society|volume=74|issue=2|page=371|year=1952|last1=Warner|first1=Donald T.|last2=Moe|first2=Owen A.}}</ref>
Several patents exist for the production of pimelic acid.<ref>{{US patent|2826609}}</ref><ref>{{US patent|2800507}}</ref><ref>{{US patent|2698339}}</ref><ref>{{US patent|3468927}}</ref><ref>{{US patent|4888443}}</ref><ref>{{US patent|2673219}}</ref>
== See also == * Diaminopimelic acid
== References == {{reflist}}
{{Navbox linear saturated dicarboxylic acids}}
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Category:Dicarboxylic acids