Glycidol is an organic compound with the formula HOCH2CHOCH2. The molecule contains both epoxide and alcohol functional groups. Being simple to make and bifunctional, it has a variety of industrial uses. The compound is a colorless, slightly viscous liquid that is slightly unstable and is not often encountered in pure form.[7]
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| Names | |
|---|---|
| Preferred IUPAC name
Oxiranylmethanol | |
| Other names
Glycidol
2,3-Epoxy-1-propanol 3-Hydroxypropylene oxide Epoxypropyl alcohol Hydroxymethyl ethylene oxide 2-Hydroxymethyl oxiran | |
| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.008.300 |
| KEGG | |
PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C3H6O2 | |
| Molar mass | 74.079 g·mol−1 |
| Appearance | Viscous liquid |
| Density | 1.1143 g/cm3[1] |
| Melting point | −54 °C (−65 °F; 219 K)[3] |
| Boiling point | 167 °C (333 °F; 440 K) (decomposes)[1] |
| miscible[2] | |
| Vapor pressure | 0.9 mmHg (25°C)[2] |
| Hazards | |
| NFPA 704 (fire diamond) | |
| Flash point | 66 °C (151 °F; 339 K)[3] |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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420 mg/kg (oral, rat)[3][4] 1980 mg/kg (dermal, rabbit)[3][5] |
LC50 (median concentration)
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450 ppm (mouse, 4 hr) 580 ppm (rat, 8 hr)[6] |
| NIOSH (US health exposure limits): | |
PEL (Permissible)
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TWA 50 ppm (150 mg/m3)[2] |
REL (Recommended)
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TWA 25 ppm (75 mg/m3)[2] |
IDLH (Immediate danger)
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150 ppm[2] |
| Safety data sheet (SDS) | External MSDS |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis and applications
editGlycidol is prepared by the epoxidation of allyl alcohol. A typical catalyst is tungstic acid, and a typical O-atom source is aqueous peroxyacetic acid.[8]
Some useful products derived from glycidol are 2,3-epoxypropyloxy chloroformate (from phosgene) and glycidyl urethanes (by addition of isocyanates:[8]
- HOCH2CH(O)CH2 + COCl2 → ClC(O)OCH2CH(O)CH2 + HCl
- HOCH2CH(O)CH2 + RNCO → RNHC(O)OCH2CH(O)CH2
Glycidol is used as a chemical intermediate in the synthesis of other glycidyl ethers, esters, and amines.[9]
Glycidol can be O-benzylated in the presence of strong base.[10] More typically, such glycidol ethers are produced by reaction of epichlorohydrin with alkoxides.[11]
Glycidol is a precursor to diproqualone (by alkylation of 2-methylquinazolin-4(3H)-one) and dyphylline (by alkylation of theophylline).
Occurrence
editGlycidyl fatty acid esters that are thought to contaminate some edible oils could be a source of traces of glycidol in the diet. These esters are formed during the deodorization step of edible oil refining, which uses vapor and high temperatures to remove impurities. The reaction conditions in that step can allow monoglyceride and diglycerides (MAG, DAG) naturally present in the oil to rearrange into glycidyl fatty acid esters.[12]
Safety
editGlycidol is an irritant of the skin, eyes, mucous membranes, and upper respiratory tract. Exposure to glycidol may also cause central nervous system depression, followed by central nervous system stimulation.[13] It is listed as an IARC Group 2A Agent, meaning that it is "probably carcinogenic to humans".[14] In regards to occupational exposures, the Occupational Safety and Health Administration has set a permissible exposure limit at 50 ppm over an eight-hour work shift, while the National Institute for Occupational Safety and Health recommends a limit at 25 ppm over an eight-hour work shift.[15]
See also
editReferences
edit- ^ a b Merck Index, 11th Edition, 4385
- ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0303". National Institute for Occupational Safety and Health (NIOSH).
- ^ a b c d Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
- ^ Food and Cosmetics Toxicology. Vol. 19, Pg. 347, 1981
- ^ AMA Archives of Industrial Health. Vol. 14, Pg. 250, 1956
- ^ "Glycidol". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ Johnson, Roy A.; Burgos-Lepley, Carmen E. (2001). "Glycidol". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rg005. ISBN 0-471-93623-5.
- ^ a b Guenter Sienel, Robert Rieth, Kenneth T. Rowbottom "Epoxides" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a09_531
- ^ Glycidol at chemicalland21.com
- ^ Bruce H. Lipshutz, Robert Moretti, and Robert Crow (1990). "Mixed Higher-Order Cyanocuprate-Induced Epoxide Openings: 1-Benzyloxy-4-Penten-2-Ol". Organic Syntheses. 69: 80. doi:10.15227/orgsyn.069.0080.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Sutter, Marc; Silva, Eric Da; Duguet, Nicolas; Raoul, Yann; Métay, Estelle; Lemaire, Marc (2015). "Glycerol Ether Synthesis: A Bench Test for Green Chemistry Concepts and Technologies" (PDF). Chemical Reviews. 115 (16): 8609–8651. doi:10.1021/cr5004002. PMID 26196761.
- ^ Cheng, Wei-wei; Liu, Guo-qin; Wang, Li-qing; Liu, Zeng-she (2017). "Glycidyl Fatty Acid Esters in Refined Edible Oils: A Review on Formation, Occurrence, Analysis, and Elimination Methods". Comprehensive Reviews in Food Science and Food Safety. 16 (2): 263–281. doi:10.1111/1541-4337.12251. ISSN 1541-4337. PMID 33371535.
- ^ "OSHA guidelines for glycidol". Archived from the original on 2012-09-25. Retrieved 2006-10-20.
- ^ "List of Classifications, Agents classified by the IARC Monographs, Volumes 1–124". IARC Monographs on the Evaluation of Risk to Humans. IARC. July 7, 2019. Retrieved July 14, 2019.
- ^ CDC - NIOSH Pocket Guide to Chemical Hazards
Further reading
edit- Axel Kleemann, Rudolf M. Wagner (1981). Glycidol: Properties, Reactions, Applications. Hüthig. ISBN 9783778507094.
- Herzberger, Jana; Niederer, Kerstin; Pohlit, Hannah; Seiwert, Jan; Worm, Matthias; Wurm, Frederik R.; Frey, Holger (2016). "Polymerization of Ethylene Oxide, Propylene Oxide, and Other Alkylene Oxides: Synthesis, Novel Polymer Architectures, and Bioconjugation". Chemical Reviews. 116 (4): 2170–2243. doi:10.1021/acs.chemrev.5b00441. PMID 26713458.
- Sutter, Marc; Silva, Eric Da; Duguet, Nicolas; Raoul, Yann; Métay, Estelle; Lemaire, Marc (2015). "Glycerol Ether Synthesis: A Bench Test for Green Chemistry Concepts and Technologies" (PDF). Chemical Reviews. 115 (16): 8609–8651. doi:10.1021/cr5004002. PMID 26196761.
- Hanson, Robert M. (1991). "The synthetic methodology of nonracemic glycidol and related 2,3-epoxy alcohols". Chemical Reviews. 91 (4): 437–475. doi:10.1021/cr00004a001.