2-Ethylhexanoic acid

2-Ethylhexanoic acid
Skeletal formula of 2-ethylhexanoic acid
Skeletal formula of 2-ethylhexanoic acid
2-Ethylhexanoic acid molecule
Names
Preferred IUPAC name
2-Ethylhexanoic acid[1]
Identifiers
3D model (JSmol)
1750468
ChEMBL
ChemSpider
ECHA InfoCard 100.005.222 Edit this at Wikidata
EC Number
  • 205-743-6
MeSH 2-ethylhexanoic+acid
RTECS number
  • MO7700000
UNII
  • InChI=1S/C8H16O2/c1-3-5-6-7(4-2)8(9)10/h7H,3-6H2,1-2H3,(H,9,10) checkY
    Key: OBETXYAYXDNJHR-UHFFFAOYSA-N checkY
  • CCCCC(CC)C(O)=O
Properties
C8H16O2
Molar mass 144.214 g·mol−1
Appearance Colorless liquid
Density 903 mg mL−1
Melting point −59.00 °C; −74.20 °F; 214.15 K
Boiling point 228.1 °C; 442.5 °F; 501.2 K
log P 2.579
Vapor pressure <1 Pa (at 25 °C)
Acidity (pKa) 4.819
Basicity (pKb) 9.178
1.425
Thermochemistry
−635.1 kJ mol−1
-4.8013–4.7979 MJ mol−1
Hazards
GHS labelling:
GHS05: Corrosive GHS07: Exclamation mark GHS08: Health hazard
Danger
H312, H318, H361
P280, P305+P351+P338
Flash point 114 °C (237 °F; 387 K)
371 °C (700 °F; 644 K)
Explosive limits 0.9–6.7%
Lethal dose or concentration (LD, LC):
  • 1.142 g kg−1 (dermal, rabit)
  • 3 g kg−1 (oral, rat)
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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2-Ethylhexanoic acid (2-EHA), commonly known as octoic acid,[2] is the organic compound with the formula CH3(CH2)3CH(C2H5)CO2H. It is a carboxylic acid that is widely used to prepare lipophilic metal derivatives that are soluble in nonpolar organic solvents. 2-Ethylhexanoic acid is a colorless viscous oil. It is supplied as a racemic mixture.

Production

2-Ethylhexanoic acid is produced industrially from propylene, which is hydroformylated to give butyraldehyde. Aldol condensation of the aldehyde gives 2-ethylhexenal, which is hydrogenated to give 2-ethylhexanal. Oxidation of this aldehyde gives the carboxylic acid.[3]

Metal ethylhexanoates

65% Solution of cobalt(II) bis(2-ethylhexanoate) in mineral spirits, tilted vial to illustrate color and viscosity.

2-Ethylhexanoic acid forms compounds with metal cations that have stoichiometry as metal acetates. These ethylhexanoate complexes are used in organic and industrial chemical synthesis.[4] They function as catalysts in polymerizations as well as for oxidation reactions as "oil drying agents."[5] They are highly soluble in nonpolar solvents. These metal complexes are often described as salts. They are, however, not ionic but charge-neutral coordination complexes. Their structures are akin to the corresponding acetates.

Examples of metal ethylhexanoates

Regulations

2-Ethylhexanoic acid is banned in the EU for use in cosmetics.[8]

See also

References

  1. ^ "2-ethylhexanoic acid - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification and Related Records. Retrieved 21 February 2012.
  2. ^ Economic Impact Analysis of Proposed Test Rule for 2-ethylhexanoic Acid (final) (epa Contract No. 68-01-6630) (Report). Environmental Protection Agency, Washington, DC. Office of Toxic. 2000.
  3. ^ Riemenschneider, Wilhelm (2002). "Carboxylic Acids, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a05_235. ISBN 978-3527306732.
  4. ^ Mishra, Shashank; Daniele, Stéphane; Hubert-Pfalzgraf, Liliane G. (2007). "Metal 2-Ethylhexanoates and Related Compounds as Useful Precursors in Materials Science". Chemical Society Reviews. 36 (11): 1770–1787. doi:10.1039/B614334M. PMID 18213985.
  5. ^ Raju, Ravinder; Prasad, Kapa (2012). "Synthetic applications of 2-ethylhexanoic acid derived reagents". Tetrahedron. 68 (5): 1341–1349. doi:10.1016/j.tet.2011.10.078.
  6. ^ Coulembier, O.; Degee, P.; Hedrick, J. L.; Dubois, P. (2006). "Controlled Ring-Opening Polymerization to Biodegradable Aliphatic Polyester: Especially Poly(Β-Malic Acid) Derivatives". Prog. Polym. Sci. 31: 723–747. doi:10.1016/j.progpolymsci.2006.08.004.
  7. ^ Burrows, Cynthia J.; Wey, Shiow-Jyi (2001). "Nickel(II) 2-Ethylhexanoate". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn014m. ISBN 0-471-93623-5.
  8. ^ Commission Regulation (EU) 2023/1490 of 19 July 2023 amending Regulation (EC) No 1223/2009 of the European Parliament and of the Council as regards the use in cosmetic products of certain substances classified as carcinogenic, mutagenic or toxic for reproduction