Cinnamic acid: Difference between revisions

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'''Cinnamic acid''' is an [[organic compound]] with the formula C<sub>6</sub>H<sub>5</sub>CHCHCO<sub>2</sub>H. It is a white crystalline compound that is slightly [[soluble]] in water, and freely soluble in many organic solvents.<ref name="ONSC">{{Cite journal | url = http://lxsrv7.oru.edu/~alang/onsc/solubility/allsolvents.php?solute=cinnamic+acid | title = Open Notebook Science Challenge: Solubilities of Organic Compounds in Organic Solvents | journal = Nature Precedings | date = 2010 | doi = 10.1038/npre.2010.4243.3}}</ref> Classified as an unsaturated [[carboxylic acid]], it occurs naturally in a number of plants. It exists as both a cis and a trans isomer, although the latter is more common.<ref name=Ullmann/>
'''Cinnamic acid''' is an [[organic compound]] with the formula C<sub>6</sub>H<sub>5</sub>CHCHCO<sub>2</sub>H. It is a white crystalline compound that is slightly [[soluble]] in water, and freely soluble in many organic solvents.<ref name=Merck/> Classified as an unsaturated [[carboxylic acid]], it occurs naturally in a number of plants. It exists as both a [[Cis–trans isomerism|''cis'' and a ''trans'' isomer]], although the latter is more common.<ref name=Ullmann/>


==Occurrence and production==
==Occurrence and production==
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==Uses==
==Uses==
Cinnamic acid is used in flavors, [[Indigo dye#Chemical synthesis|synthetic indigo]], and certain [[pharmaceuticals]]. A major use is in the manufacturing of the methyl, ethyl, and benzyl [[ester]]s for the perfume industry.<ref name=Merck/> Cinnamic acid is a precursor to the sweetener [[aspartame]] via enzyme-catalysed amination to [[phenylalanine]].<ref name=Ullmann/> Cinnamic acid can [[Dimer_(chemistry)|dimerize]] in non-polar solvents resulting in different [[Free-energy_relationship|linear free energy relationships]].<ref>J-C Bradley ''et al.'', [https://dx.doi.org/10.1186/s13065-015-0080-9 &ldquo;Determination of Abraham model solute descriptors for the monomeric and dimeric forms of trans-cinnamic acid using measured solubilities from the Open Notebook Science Challenge&rdquo;], ''Chemistry Central Journal'' 9:11 (2015)</ref>
Cinnamic acid is used in flavors, [[Indigo dye#Chemical synthesis|synthetic indigo]], and certain [[pharmaceuticals]]. A major use is in the manufacturing of the methyl, ethyl, and benzyl [[ester]]s for the perfume industry.<ref name=Merck/> Cinnamic acid is a precursor to the sweetener [[aspartame]] via enzyme-catalysed amination to [[phenylalanine]].<ref name=Ullmann/> Cinnamic acid can [[Dimer_(chemistry)|dimerize]] in non-polar solvents resulting in different [[Free-energy_relationship|linear free energy relationships]].<ref>{{cite journal | doi = 10.1186/s13065-015-0080-9 }}</ref>

==References==
==References==
{{Reflist}}
{{Reflist}}

Revision as of 14:32, 30 January 2018

Cinnamic acid
Skeletal formula of cinnamic acid
Ball-and-stick model of the cinnamic acid molecule
Sample of compound
Names
Preferred IUPAC name
(2E)-3-Phenylprop-2-enoic acid
Other names
Cinnamic acid
trans-Cinnamic acid
Phenylacrylic acid[1]
Cinnamylic acid
3-Phenylacrylic acid
(E)-Cinnamic acid
Benzenepropenoic acid
Isocinnamic acid
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.004.908 Edit this at Wikidata
KEGG
UNII
  • InChI=1S/C9H8O2/c10-9(11)7-6-8-4-2-1-3-5-8/h1-7H,(H,10,11)/b7-6+ checkY
    Key: WBYWAXJHAXSJNI-VOTSOKGWSA-N checkY
  • InChI=1/C9H8O2/c10-9(11)7-6-8-4-2-1-3-5-8/h1-7H,(H,10,11)/b7-6+
    Key: WBYWAXJHAXSJNI-VOTSOKGWBT
  • O=C(O)\C=C\c1ccccc1
Properties
C9H8O2
Molar mass 148.161 g·mol−1
Appearance White monoclinic crystals
Density 1.2475 g/cm3[2]
Melting point 133 °C (271 °F; 406 K)[2]
Boiling point 300 °C (572 °F; 573 K)[2]
500 mg/L[2]
Acidity (pKa) 4.44
-78.36·10−6 cm3/mol
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
1
0
Flash point > 100 °C (212 °F; 373 K)[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Cinnamic acid is an organic compound with the formula C6H5CHCHCO2H. It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents.[3] Classified as an unsaturated carboxylic acid, it occurs naturally in a number of plants. It exists as both a cis and a trans isomer, although the latter is more common.[4]

Occurrence and production

Natural occurrence

It is obtained from oil of cinnamon, or from balsams such as storax.[3] It is also found in shea butter. Cinnamic acid has a honey-like odor;[5] it and its more volatile ethyl ester (ethyl cinnamate) are flavor components in the essential oil of cinnamon, in which related cinnamaldehyde is the major constituent. Cinnamic acid is also part of the biosynthetic shikimate and phenylpropanoid pathways. Its biosynthesis is performed by action of the enzyme phenylalanine ammonia-lyase (PAL) on phenylalanine.

Production

The original synthesis of cinnamic acid involves the Perkin reaction, which entails the base-catalysed condensation of acetic anhydride and benzaldehyde. Rainer Ludwig Claisen (1851–1930) described the synthesis of cinnamate esters by the reaction of benzaldehyde and esters.[6] The reaction is known as the Aldol condensation (with accompanying hydrolysis of the anhydride).

Synthesis of cinnamic acid via Perkin reaction

It can also be prepared from cinnamaldehyde and benzal chloride.[4]

Another way of preparing Cinnamic acid is by the Knövenaegel–Hans condensation reaction.[7] The reactants for this are the corresponding benzaldehyde and malonic acid in the presence of a weak base, followed by acid hydrolysis.

Uses

Cinnamic acid is used in flavors, synthetic indigo, and certain pharmaceuticals. A major use is in the manufacturing of the methyl, ethyl, and benzyl esters for the perfume industry.[3] Cinnamic acid is a precursor to the sweetener aspartame via enzyme-catalysed amination to phenylalanine.[4] Cinnamic acid can dimerize in non-polar solvents resulting in different linear free energy relationships.[8]

References

  1. ^ "Cinnamic Acid" . Encyclopædia Britannica. Vol. 6 (11th ed.). 1911. p. 376.
  2. ^ a b c d e Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  3. ^ a b c Budavari, Susan, ed. (1996), The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (12th ed.), Merck, ISBN 0911910123
  4. ^ a b c Dorothea Garbe "Cinnamic Acid" in Ullmann's Encyclopedia of Industrial Chemistry, 2000, Wiley-VCH, Weinheim. doi:10.1002/14356007.a07_099
  5. ^ Cinnamic acid, flavornet.org
  6. ^ Claisen, L. (1890) "Zur Darstellung der Zimmtsäure und ihrer Homologen" (On the preparation of cinnamic acid and its homologues), Berichte der deutschen chemischen Gesellschaft, 23 : 976–978.
  7. ^ L. Tieze, Reactions and Synthesis in the Organic Chemistry Laboratory, Mill Vall, California, 1988, p. 1988.
  8. ^ . doi:10.1186/s13065-015-0080-9. {{cite journal}}: Cite journal requires |journal= (help); Missing or empty |title= (help)CS1 maint: unflagged free DOI (link)
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