propargyl bromide
{{short description|Chemical compound}}
{{Chembox
|Name = Propargyl bromide
|ImageFile = Propargyl bromide.svg
|PIN = 3-Bromoprop-1-yne
|OtherNames = 3-Bromo-1-propyne
Bromopropyne
1-Brom-2-propin
1-Bromo-2-propyne
gamma-Bromoallylene
2-Propynyl bromide
Propargyl bromide
Propynyl bromide
|Section1={{Chembox Identifiers
|CASNo = 106-96-7
|UNII_Ref = {{fdacite|correct|FDA}}
|UNII = F3H7ZXK9ZU
|ChemSpiderID = 7554
|InChI = InChI=1S/C3H3Br/c1-2-3-4/h1H,3H2
|PubChem = 7842
|SMILES = BrCC#C
}}
|Section2={{Chembox Properties
|Appearance = colourless liquid
|BoilingPtC = 89
|BoilingPt_ref = {{GESTIS|ZVG=490139}}
|C=3 | H=3 | Br=1
|LogP = 1.179
|MeltingPtC = -61.1
|Solubility = insoluble
|SolubleOther = Soluble in organic solvents
|VaporPressure = 72 mbar (20 °C)}}
|Section3={{Chembox Structure
}}
|Section7={{Chembox Hazards
|AutoignitionPtC = 324
|FlashPtC = 18
|MainHazards = Highly Flammable, Toxic, Corrosive
|NFPA-H = 3
|NFPA-F = 3
|NFPA-R = 4
|NFPA-S =
}}
}}
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.
Applications and production
Propargyl bromide can also be used as an intermediate for the synthesis of organic compounds, including agrochemicals and pharmaceuticals. In the 1960s, it was used in a soil fumigant called Trizone.Franz Müller and Arnold P. Applebyki "Weed Control, 2. Individual Herbicides" in Ullmann's Encyclopedia of Industrial Chemistry, 2010, {{doi|10.1002/14356007.o28_o01}}
Propargyl bromide may be produced by the treatment of propargyl alcohol with phosphorus tribromide.{{cite web | url=http://www.freepatentsonline.com/6794551.html
| title= Process for Producing Propargyl Bromide | accessdate= November 7, 2012}}
Reactions
Propargyl bromide is an alkylating agent. For example, it reacts with dimethylsulfide, it reacts to give the sulfonium salt:{{cite journal |doi=10.15227/orgsyn.053.0001|author=P. D. Howes, C. J. M. Stirling|title=3-Acetyl-2,4-Dimethylfuran |journal=Organic Syntheses |year=1973 |volume=53 |page=1 }}
:{{chem2|HCCCH2Br + S(CH3)2 -> [HCCCH2S(CH3)2]Br}}
It alkylates even weakly basic amines such as aniline.{{cite journal |doi=10.15227/orgsyn.089.0294|title=Synthesis of Quinolines by Electrophilic Cyclization of N-(2-Alkynyl)Anilines: 3-Iodo-4-Phenylquinoline |journal=Organic Syntheses |year=2012 |volume=89 |page=294|author=Yu Chen, Anton Dubrovskiy, Richard C. Larock |doi-access=free }}
Aldehydes react with propargyl bromide in a Barbier-type reaction to yield alkynyl alcohols:{{cite journal |last1=Jõgi |first1=Artur |last2=Mäeorg |first2=Uno |title=Zn Mediated Regioselective Barbier Reaction of Propargylic Bromides in THF/aq. {{chem|N|H|4|Cl}} Solution |journal=Molecules |date=30 November 2001 |volume=6 |issue=12 |pages=964–968 |doi=10.3390/61200964 |doi-access=free }}
At low temperatures, upon treatment with magnesium, propargyl bromide gives the Grignard reagent formally derived from allenyl bromide, i.e., CH2=C=CHMgBr.{{OrgSynth|author=Henning Hopf, Ingrid Böhm, and Jürgen Kleinschroth|year=1990|title=
Safety
Propargyl bromide is a lachrymator and an alkylating agent,{{cite web | url=http://www.toxnet.nlm.nih.gov/cgi-bin/sis/search/r?dbs+hsdb:@term+@rn+@rel+106-96-7
| title= 3-Bromo-1-Propyne | accessdate= November 3, 2012}} 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.{{cite book |doi=10.1016/B978-0-08-100971-0.00055-X |chapter=C1 |title=Bretherick's Handbook of Reactive Chemical Hazards |date=2017 |pages=81–882 |isbn=978-0-08-100971-0 |editor1-first=P.G. |editor1-last=Urben }}