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Ethyl octanoate

Names
Preferred IUPAC name Ethyl octanoate
Other names Ethyl caprylate
Identifiers
CAS Number	106-32-1
3D model (JSmol)	Interactive image
ChemSpider	7511
ECHA InfoCard	100.003.078
EC Number	203-385-5
PubChem CID	7799
RTECS number	RH0680000
UNII	81C5MOP582
CompTox Dashboard (EPA)	DTXSID8051542
InChI InChI=1S/C10H20O2/c1-3-5-6-7-8-9-10(11)12-4-2/h3-9H2,1-2H3Key: YYZUSRORWSJGET-UHFFFAOYSA-N
SMILES O=C(OCC)CCCCCCC
Properties
Chemical formula	C10H20O2
Molar mass	172.268 g·mol
Density	0.86215 g/cm
Melting point	−48 °C (−54 °F; 225 K)
Boiling point	208 °C (406 °F; 481 K)
Solubility in water	70.1 mg/L
Vapor pressure	0.2 mbar at 20 °C; 3.18 mbar at 60 °C
Viscosity	1.411 mPa·s
Hazards
Flash point	79 °C (174 °F; 352 K)
Autoignition temperature	325 °C (617 °F; 598 K)
Explosive limits	0.7 - Vol.%
Lethal dose or concentration (LD, LC):
LD50 (median dose)	25.96 g/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Infobox references

Ethyl octanoate, also known as ethyl caprylate, is a fatty acid ester formed from caprylic acid and ethanol. A colorless liquid at room temperature, it has the semi-developed formula of CH₃(CH₂)₆COOCH₂CH₃, and is used in food industries as a flavoring and in the perfume industry as a scent additive. It is present in many fruits and alcoholic beverages, and has a strong odor of fruit and flowers. It is used in the creation of synthetic fruity scents.

Synthesis

Ethyl octanoate can be synthesized from caprylic acid and ethanol via a classic Fischer–Speier esterification.

${\displaystyle {\ce {CH3(CH2)6COOH + CH3CH2OH <=> CH3(CH2)6COOCH2CH3 + H2O}}}$

Equilibrium can be shifted towards the right side of the equation through removal of water.

Uses

Ethyl octanoate does not see widespread use due to the greater availability of reasonably similar esters such as ethyl acetate. However, there are certain applications where it fills a niche. Ethyl octanoate has a strong odor of fruit and flowers and a taste of apricot, and as such it can be used as a flavoring or to create scents. It sees some use as a cleaning agent.

Ethyl octanoate also sees incidental use. It is found in some wines, where overall ester concentration and composition is considered important to the flavor and aroma profile.

Safety

Like many esters, ethyl octanoate is not considered to be toxic. LD50 in rats is 25.96 g/kg. Though it has a low explosive limit of only 0.67 vol%, it is also weakly volatile, with a vapor pressure of only 0.2 mbar at room temperature. Ethyl octanoate is combustible.

References

1. ^ Sheu, Yaw-Wen; Tu, Chein-Hsiun (2006). "Densities and Viscosities of Binary Mixtures of Isoamyl Acetate, Ethyl Caproate, Ethyl Benzoate, Isoamyl Butyrate, Ethyl Phenylacetate, and Ethyl Caprylate with Ethanol at T = (288.15, 298.15, 308.15, and 318.15) K". Journal of Chemical and Engineering Data. 51 (2): 496–503. doi:10.1021/je050389b.
2. ^ Ethyl octanoate from PubChem, accessed 30 December 2023
3. Mark, James E. (2007). Physical Properties of Polymer Handbook (2nd ed.). Springer. p. 294. ISBN 978-0387690025. Retrieved 1 March 2013.
4. ^ Record of Ethyl octanoate in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 10 August 2010.
5. Fahlbusch, Karl-Georg; Hammerschmidt, Franz-Josef; Panten, Johannes; Pickenhagen, Wilhelm; Schatkowski, Dietmar; Bauer, Kurt; Garbe, Dorothea; Surburg, Horst (15 January 2003). "Flavors and Fragrances". Flavors and Flagrances. Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag GmbH & Co. doi:10.1002/14356007.a11_141. ISBN 3527306730.
6. "Ethyl octanoate - Substance Information - ECHA". echa.europa.eu. Retrieved 2021-07-12.
7. Marais, J. et al. (2003) http://www.sawislibrary.co.za/dbtextimages/MaraisJ10.pdf "Effect of Different Wine-Making Techniques on the Composition and Quality of Pinotage Wine. I. Low-Temperature Skin Contact Prior to Fermentation"

• Octanoate esters
• Ethyl esters