Propargyl alcohol, or 2-propyn-1-ol, is an organic compound with the formula C3H4O. It is the simplest stable alcohol containing an alkyne functional group.[3] Propargyl alcohol is a colorless viscous liquid that is miscible with water and most polar organic solvents.
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| Names | |
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| Preferred IUPAC name
Prop-2-yn-1-ol | |
| Other names
propynol, 2-propynol, 2-propyn-1-ol, hydroxymethylacetylene.
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| Identifiers | |
3D model (JSmol)
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| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.003.157 |
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| KEGG | |
PubChem CID
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| UNII | |
| UN number | 1986 2929 |
CompTox Dashboard (EPA)
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| Properties | |
| C3H4O | |
| Molar mass | 56.064 g·mol−1 |
| Appearance | Colorless to straw-colored liquid[1] |
| Odor | geranium-like[1] |
| Density | 0.9715 g/cm3 |
| Melting point | −51 to −48 °C (−60 to −54 °F; 222 to 225 K) |
| Boiling point | 114 to 115 °C (237 to 239 °F; 387 to 388 K) |
| miscible[1] | |
| Vapor pressure | 12 mmHg (20 °C)[1] |
| Hazards[2] | |
| GHS labelling: | |
    
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| Danger | |
| H226, H301, H310, H314, H330, H373, H411 | |
| P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P273, P280, P301 P310, P301 P330 P331, P302 P352, P303 P361 P353, P304 P340, P305 P351 P338, P310, P311, P312, P321, P322, P330, P361, P363, P370 P378, P391, P403 P233, P403 P235, P405, P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | 36 °C; 97 °F; 309 K (open cup)[1] |
| NIOSH (US health exposure limits): | |
PEL (Permissible)
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none[1] |
REL (Recommended)
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TWA 1 ppm (2 mg/m3) [skin][1] |
IDLH (Immediate danger)
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N.D.[1] |
| Safety data sheet (SDS) | External SDS |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Reactions and applications
editPropargyl alcohol polymerizes with heating or treatment with base. It is used as a corrosion inhibitor, a metal complex solution, a solvent stabilizer and an electroplating brightener additive. It is also used as an intermediate in organic synthesis. Secondary and tertiary substituted propargylic alcohols undergo catalyzed rearrangement reactions to form α,β-unsaturated carbonyl compounds via the Meyer–Schuster rearrangement and others. It can be oxidized to propynal[4] or propargylic acid.
As an indication of the electronegativity of an sp carbon, propargyl alcohol is significantly more acidic (pKa = 13.6) compared to its sp2-containing analog allyl alcohol (pKa = 15.5), which is in turn more acidic than the fully saturated (sp3 carbons only) n-propyl alcohol (pKa = 16.1).[5]
Preparation
editPropargyl alcohol is produced by the copper-catalysed addition of formaldehyde to acetylene as a by-product of the industrial synthesis of but-2-yne-1,4-diol.[6] It can also be prepared by dehydrochlorination of 3-chloro-2-propen-1-ol by NaOH.[7]
Safety
editPropargyl alcohol is a flammable liquid, toxic by inhalation, highly toxic by ingestion, toxic by skin absorption, and corrosive.[citation needed]
See also
editReferences
edit- ^ a b c d e f g h NIOSH Pocket Guide to Chemical Hazards. "#0527". National Institute for Occupational Safety and Health (NIOSH).
- ^ Record of Prop-2-yn-1-ol in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 11 March 2020.
- ^ Merck Index, 11th Edition, 7819
- ^ J. C. Sauer (1956). "Propionaldehyde". Organic Syntheses. 36: 66; Collected Volumes, vol. 4, p. 813.
- ^ Anslyn, Eric V., 1960- (2006). Modern physical organic chemistry. Dougherty, Dennis A., 1952-. Mill Valley, California: University Science Books. ISBN 1-891389-31-9. OCLC 55600610.
{{cite book}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link) - ^ Falbe, Jürgen; Bahrmann, Helmut; Lipps, Wolfgang; Mayer, Dieter. "Alcohols, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a01_279. ISBN 978-3527306732..
- ^ [1] J. Am. Chem. Soc., 1944, 66 (2), pp 285–287