2-ethylhexanol

Structural formula
	Simplified structural formula without stereochemistry - 1: 1 mixture of enantiomers
General
Surname	2-ethylhexanol
other names	2-ethyl-1-hexanol; 2-ethylhexyl alcohol; Isooctan-1-ol; 1-isooctanol; iso- caprylic alcohol; 2-ethylhexan-1-ol; Isooctyl alcohol; EHOL;
Molecular formula	C 8 H 18 O
Brief description	colorless liquid with an alcohol-like odor
External identifiers / databases
EC number	203-234-3
ECHA InfoCard	100.002.941
PubChem	7720
Wikidata	Q209388
properties
Molar mass	130.23 g mol −1
Physical state	liquid
density	0.83 g cm −3 (20 ° C)
Melting point	<−76 ° C
boiling point	184.7 ° C
Vapor pressure	0.48 hPa (20 ° C)
solubility	poorly soluble in water (0.6 g l −1 at 20 ° C); soluble in ethanol, diethyl ether, acetone, benzene, chloroform;
Refractive index	1.4300 (20 ° C)
safety instructions
GHS labeling of hazardous substances Caution
H and P phrases	H: 315-319-332-335
	P: 302 + 352-304 + 340 + 312-305 + 351 + 338
MAK	DFG : 10 ml m −3 , 54 mg m −3 ; Switzerland: 20 ml m −3 or 110 mg m −3 ;
Toxicological data	3730 mg kg −1 ( LD 50 , rat , oral ) ; 1970 mg kg −1 ( LD 50 , rabbit , transdermal ) ;
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

2-Ethylhexanol (2-EH for short) is a fully synthetic, branched primary alcohol with an alcohol-like odor. It is of little importance as a solvent . Most of it is chemically processed.

Isomers

2-Ethylhexanol forms two enantiomers , ( R ) -2-ethylhexanol and the mirror-image ( S ) -2-ethylhexanol. If 2-ethylhexanol is mentioned without a stereochemical descriptor , this usually means the racemate , a 1: 1 mixture of both isomers.

Isomers of 2-ethylhexanol
Surname	( R ) -2-ethylhexanol	( S ) -2-ethylhexanol
other names
Structural formula
CAS number	50373-29-0	128821-84-1
	104-76-7 (unspec.)
EC number	-	-
	203-234-3 (unspec.)
ECHA info card	-	-
	100.002.941 (unspec.)
PubChem	6991979	6991980
	7720 (unspec.)
Wikidata	Q75187061	Q75187088
	Q209388 (unspec.)

Technical manufacturing

The starting material for the production of racemic 2-ethylhexanol is propene , which, in addition to ethene, is formed during steam cracking . The propene is first reacted with carbon monoxide and hydrogen in a hydroformylation reaction to form butanal (butyraldehyde). This in turn reacts in an aldol condensation to form 2-ethyl-3-hydroxyhexanal .

After elimination of water and catalytic hydrogenation , 2-ethylhexanol is obtained.

Another synthetic route is the reduction of 2-ethylhexanal .

properties

Physical Properties

2.7% by weight of water dissolves in 2-ethylhexanol at 20 ° C, while 0.1% by weight of water dissolves at 20 ° C. The azeotrope with water boils at 99.1 ° C and contains 80% water.

Chemical properties

The odor of the ( R ) -enantiomer was described as “heavy, earthy and slightly flowery”, while it was given as “light and flowery-sweet” for the ( S ) -enantiomer.

use

In a few cases, ethylhexanol is used as a solvent for non-polar substances.
Ethylhexanol is esterified with phthalic acid or adipic acid. The resulting diethylhexyl phthalate (DEHP) or diethylhexyl adipate (DEHA) is used as a plasticizer in plastics, mostly PVC .
Ethylhexanol is also reacted with ethylene oxide and used as a nonionic surfactant .
It is the raw material for:
- 2-ethylhexyl sulfate , which, for example, as a solubilizer is used
- 2-ethylhexylamine
- 2-ethylhexyl acrylate , which, for example, as a monomer for polyacrylates is used

safety instructions

When inhaling, coughing, dizziness, headache, sore throat and fatigue may occur. Skin and eyes can be irritated. 2-Ethylhexanol forms flammable vapor-air mixtures at high temperatures. With a flash point of 73 ° C, the substance is considered to be hardly inflammable. The explosion range is between approx. 0.79 vol.% As the lower explosion limit (LEL) and approx. 43 vol.% As the upper explosion limit (UEL). The ignition temperature is 270 ° C. The substance therefore falls into temperature class T3.

2-Ethylhexanol was included by the EU in 2014 in accordance with Regulation (EC) No. 1907/2006 (REACH) in the context of substance evaluation in the Community's ongoing action plan ( CoRAP ). The effects of the substance on human health and the environment are re-evaluated and, if necessary, follow-up measures are initiated. The reasons for the uptake of 2-ethylhexanol were concerns about consumer use , high (aggregated) tonnage, high risk characterization ratio (RCR) and widespread use as well as the dangers arising from a possible assignment to the group of CMR substances. The re-evaluation took place from 2014 and was carried out by Poland . A final report was then published.

literature

Carlo Carlini, Alessandro Macinai, Anna Maria Raspolli Galletti, Glauco Sbrana: Selective synthesis of 2-ethyl-1-hexanol from n-butanol through the Guerbet reaction by using bifunctional catalysts based on copper or palladium precursors and sodium butoxide , Journal of Molecular Catalysis A: Chemical , 2004, 212 (1-2), pp. 65-70 ( doi: 10.1016 / j.molcata.2003.10.045 ).
Ning Liang, Xiaolong Zhang, Hualiang An, Xinqiang Zhao, Yanji Wang: Direct synthesis of 2-ethylhexanol via n-butanal aldol condensation – hydrogenation reaction integration over a Ni / Ce-Al ₂ O ₃ bifunctional catalyst , Green Chemistry , 2015, 17 (5), pp. 2959-2972 ( doi: 10.1039 / C5GC00223K ).

Web links

Commons : 2-Ethylhexanol - Collection of Pictures, Videos, and Audio Files

Entry to 2-ethylhexanol . In: P. J. Linstrom, W. G. Mallard (Eds.): NIST Chemistry WebBook, NIST Standard Reference Database Number 69 . National Institute of Standards and Technology , Gaithersburg MD

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o Entry on 2-Ethylhexanol in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .
↑ ^a ^b ^c Entry on 2-Ethylhexan-1-ol. In: Römpp Online . Georg Thieme Verlag, accessed on June 15, 2017.
↑ ^a ^b David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-245.
↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 104-76-7 or 2-ethylhexanol ), accessed on October 1, 2019.
↑ ^a ^b Process for the production of 2-ethylhexanol: DE 3530839 A1 , August 29, 1985; EP 0216151 B1 , August 20, 1986.
↑ Klaus Rettinger, Christian Burschka, Peter Scheeben, Heike Fuchs, Armin Mosandl: Chiral 2-alkylbranched acids, esters and alcohols. Preparation and stereospecific flavor evaluation , Tetrahedron: Asymmetry , 1991, 2 (10), pp. 965-968 ( doi: 10.1016 / S0957-4166 (00) 86137-6 ).
^ E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.
↑ European Chemicals Agency (ECHA): Substance Evaluation Conclusion and Evaluation Report
↑ Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): 2-ethylhexan-1-ol , accessed on March 26, 2019.

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o Entry on 2-Ethylhexanol in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .

[Roempp-2] Entry on 2-Ethylhexan-1-ol. In: Römpp Online . Georg Thieme Verlag, accessed on June 15, 2017.

[CRC-3] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-245.

[4] Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 104-76-7 or 2-ethylhexanol ), accessed on October 1, 2019.

[Verfahren_zur_Herstellung_von_2-Ethylhexanol-5] Process for the production of 2-ethylhexanol: DE 3530839 A1 , August 29, 1985; EP 0216151 B1 , August 20, 1986.

[6] Klaus Rettinger, Christian Burschka, Peter Scheeben, Heike Fuchs, Armin Mosandl: Chiral 2-alkylbranched acids, esters and alcohols. Preparation and stereospecific flavor evaluation , Tetrahedron: Asymmetry , 1991, 2 (10), pp. 965-968 ( doi: 10.1016 / S0957-4166 (00) 86137-6 ).

[Brandes-7] E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.

[8] European Chemicals Agency (ECHA): Substance Evaluation Conclusion and Evaluation Report

[9] Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): 2-ethylhexan-1-ol , accessed on March 26, 2019.