Propargyl bromide
Chemical compound
From Wikipedia, the free encyclopedia
Propargyl bromide, also known as 3-bromo-prop-1-yne, is an organic compound with the chemical formula HC≡CCH2Br. A colorless liquid, it is a halogenated organic compound consisting of propyne with a bromine substituent on the methyl group. It has a lachrymatory effect, like related compounds. The compound is used as a reagent in organic synthesis.
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| Names | |
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| Preferred IUPAC name
3-Bromoprop-1-yne | |
| Other names
3-Bromo-1-propyne Bromopropyne 1-Brom-2-propin 1-Bromo-2-propyne gamma-Bromoallylene 2-Propynyl bromide Propargyl bromide Propynyl bromide | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.003.135 |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C3H3Br | |
| Molar mass | 118.961 g·mol−1 |
| Appearance | colourless liquid |
| Density | 1.57 g/mL (20 °C)[1] |
| Melting point | −61.1 °C (−78.0 °F; 212.1 K)[1] |
| Boiling point | 89 °C (192 °F; 362 K)[1] |
| insoluble | |
| Solubility | Soluble in organic solvents |
| log P | 1.179 |
| Vapor pressure | 72 mbar (20 °C)[1] |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards |
Highly Flammable, Toxic, Corrosive |
| NFPA 704 (fire diamond) | |
| Flash point | 18 °C (64 °F; 291 K)[1] |
| 324 °C (615 °F; 597 K)[1] | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Applications and production
Propargyl bromide may be produced by the treatment of propargyl alcohol with phosphorus tribromide.[2]
Reactions
Propargyl bromide is an alkylating agent. For example, it reacts with dimethylsulfide, it reacts to give the sulfonium salt:[3]
- HCCCH2Br + S(CH3)2 → [HCCCH2S(CH3)2]Br
It alkylates even weakly basic amines such as aniline.[4]
Aldehydes react with propargyl bromide in a Barbier-type reaction to yield alkynyl alcohols:[5]
At low temperatures, upon treatment with magnesium, propargyl bromide gives the Grignard reagent formally derived from allenyl bromide, i.e., CH2=C=CHMgBr.[6]
Propargyl bromide and its ether derivatives participate in azide-based click reactions.[7]
Safety
Propargyl bromide is a lachrymator and an alkylating agent,[8] This liquid acetylenic endothermic compound may be decomposed by mild shock, and when heated under confinement, it decomposes with explosive violence and may detonate. Addition of 20—30 wt% of toluene makes propargyl bromide insensitive in laboratory impact and confinement tests.[9]