2-Ethylhexanol

2-Ethylhexanol
2-Ethylhexanol molecule
Names
IUPAC name
2-Ethylhexan-1-ol[1]
Identifiers
104-76-7 YesY
1719280
ChEBI CHEBI:16011 YesY
ChEMBL ChEMBL31637 YesY
ChEMBL1229918 YesY
ChemSpider 7434 YesY
5360145 R YesY
5360146 S YesY
EC Number 203-234-3
Jmol interactive 3D Image
KEGG C02498 N
MeSH 2-ethylhexanol
PubChem 7720
6991979 R
6991980 S
UNII XZV7TAA77P YesY
Properties
C8H18O
Molar mass 130.23 g·mol−1
Appearance Colourless liquid
Density 833 mg mL−1
Melting point −76 °C (−105 °F; 197 K)
Boiling point 180 to 186 °C; 356 to 367 °F; 453 to 459 K
log P 2.721
Vapor pressure 30 Pa (at 20 °C)
1.431
Thermochemistry
317.5J K−1 mol−1
347.0 J K−1 mol−1
−433.67–−432.09 kJ mol−1
−5.28857–−5.28699 MJ mol−1
Hazards
GHS pictograms
GHS signal word DANGER
H312, H315, H318, H335
P261, P280, P305+351+338
Xn
R-phrases R21, R37/38, R41, R52/53
S-phrases S26, S36/37/39
Flash point 81 °C (178 °F; 354 K)
290 °C (554 °F; 563 K)
Explosive limits 0.88–9.7%
Lethal dose or concentration (LD, LC):
  • 1.97 g kg−1 (dermal, rabbit)
  • 3.73 g kg−1 (oral, rat)
US health exposure limits (NIOSH):
none[2]
TWA 50 ppm (270 mg/m3) [skin][2]
N.D.[2]
Related compounds
Related alkanol
Propylheptyl alcohol
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

2-Ethylhexanol (abbreviated 2-EH) is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is poorly soluble in water but soluble in most organic solvents. It is produced on a massive scale for use in numerous applications such as solvents, flavors, and fragrances and especially as a precursor for production of other chemicals such as emollients and plasticizers. It is encountered in natural plant fragrances, and the odor has been reported as "heavy, earthy, and slightly floral" for the R enantiomer and "a light, sweet floral fragrance" for the S enantiomer.[3]

Applications

Almost all 2-ethylhexanol manufactured is used as a precursor for the synthesis of the diester bis(2-ethylhexyl) phthalate (DEHP), a plasticizer. Because it is a fatty alcohol, its esters tend to have emollient properties. For example, the sunscreen octocrylene contains a 2-ethylhexyl ester for this purpose.

It is also commonly used as a low volatility solvent. 2-Ethylhexanol can also be used as an octane booster when reacted with nitric acid.

Industrial production

2-Ethylhexanol is produced industrially by the aldol condensation of n-butyraldehyde, followed by hydrogenation of the resulting hydroxyaldehyde. The overall process is very similar to that of the Guerbet reaction, by which it may also be produced.[4] About 2,500,000 tons are prepared in this way annually.[5][6] The n-butyraldehyde is made by hydroformylation of propylene, either in a self-contained plant or as the first step in a fully integrated facility. Most facilities make n-butanol and isobutanol in addition to 2-ethylhexanol.

Health effects

Air exposure of 2-ethylhexanol to a human in a case study involving concentrations between 80 and 470 μg/m3 included throat irritation, cough, sore eyes, headache and blurred vision. Other volatile organic compounds were detected in the air as well, but 2-ethylhexanol was of the highest concentration.[7] Another study involving several people exposed to 2-ethylhexanol reported headaches, dizziness, fatigue and gastrointestinal disorders, but the concentration of 2-ethylhexanol in this case is not known.[7] According to animal studies, 2-ethylhexanol does not seem to be carcinogenic.[7]

Nomenclature

Although isooctanol (and the derived isooctyl prefix) is commonly used in industry to refer to 2-ethylhexanol and its derivatives, IUPAC naming conventions[8] dictate that this name is properly applied to another isomer of octanol, 6-methylheptan-1-ol. The Chemical Abstracts Service likewise indexes isooctanol (CAS# 26952-21-6) as 6-methylheptan-1-ol.

See also

References

  1. "2-ethylhexanol - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2005. Identification and Related Records. Retrieved 29 January 2012.
  2. 1 2 3 "NIOSH Pocket Guide to Chemical Hazards #0354". National Institute for Occupational Safety and Health (NIOSH).
  3. Klaus Rettinger; Christian Burschka; Peter Scheeben; Heike Fuchs; Armin Mosandl (1991). "Chiral 2-alkylbranched acids, esters and alcohols. Preparation and stereospecific flavour evaluation". Tetrahedron: Asymmetry 2 (10): 965–968. doi:10.1016/S0957-4166(00)86137-6.
  4. Miller, Robert; Bennett, George (January 1961). "Producing 2-Ethylhexanol by the Guerbet Reaction". Industrial & Engineering Chemistry 53 (1): 33–36. doi:10.1021/ie50613a027.
  5. C. Kohlpaintner, M. Schulte, J. Falbe, P. Lappe, J. Weber, "Aldehydes, Aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry 2008, Wiley-VCH, Weinheim. doi:10.1002/14356007.a01_321.pub2.
  6. Ashford’s Dictionary of Industrial Chemicals, Third edition, 2011, page 4180-4181.
  7. 1 2 3 Assessment Report On 2-Ethylhexanol For Developing Ambient Air Quality Objectives Prepared for Alberta Environment by Toxico-Logic Consulting Inc. November 2004.
  8. IUPAC Blue Book, A2.25

External links

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