Propargyl bromide, also known as 3-bromo-prop-1-yne, is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...

with the chemical formula HC≡CCH₂Br. A colorless liquid, it is a halogenated organic compound consisting of

propyne Propyne (methylacetylene) is an alkyne with the chemical formula . It is a component of MAPD gas—along with its isomer propadiene (allene), which was commonly used in gas welding. Unlike acetylene, propyne can be safely condensed.Peter Päs ...

with a

bromine Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table (halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a simila ...

substituent on the

methyl group In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many ...

. It has a lachrymatory effect, like related compounds. The compound is used as a reagent in

organic synthesis Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one o ...

Applications and production

Propargyl bromide can also be used as an intermediate for the synthesis of organic compounds, including

agrochemicals An agrochemical or agrichemical, a contraction of ''agricultural chemical'', is a chemical product used in industrial agriculture. Agrichemical refers to biocides (pesticides including insecticides, herbicides, fungicides and nematicides) and syn ...

and

pharmaceutical A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and re ...

s. 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, Propargyl bromide may be produced by the treatment of

propargyl alcohol Propargyl alcohol, or 2-propyn-1-ol, is an organic compound with the chemical formula, formula C3H4O. It is the simplest stable Alcohol (chemistry), alcohol containing an alkyne functional group. Propargyl alcohol is a colorless viscous liquid t ...

with

phosphorus tribromide Phosphorus tribromide is a colourless liquid with the formula P Br3. The liquid fumes in moist air due to hydrolysis and has a penetrating odour. It is used in the laboratory for the conversion of alcohols to alkyl bromides. Preparation PBr3 ...

Reactions

Propargyl bromide is an alkylating agent. With

dimethylsulfide Dimethyl sulfide (DMS) or methylthiomethane is an organosulfur compound with the formula (CH3)2S. Dimethyl sulfide is a flammable liquid that boils at and has a characteristic disagreeable odor. It is a component of the smell produced from cook ...

, it reacts to give the sulfonium salt: : It also alkylates even weakly basic amines such as

aniline Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine In organic chemistry, an aromatic amine is an organic compound consisting of an aroma ...

. Aldehydes react with propargyl bromide in a Barbier-type reaction to yield alkynyl alcohols: : At low temperatures, upon treatment with magnesium, propargyl bromide gives the

Grignard reagent A Grignard reagent or Grignard compound is a chemical compound with the general formula , where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride and phenylmagnesium bromide ...

formally derived from allenyl bromide, i.e., CH₂=C=CHMgBr.

Safety

Propargyl bromide is a

lachrymator Tear gas, also known as a lachrymator agent or lachrymator (), sometimes colloquially known as "mace" after the early commercial aerosol, is a chemical weapon that stimulates the nerves of the lacrimal gland in the eye to produce tears. In ad ...

and an

alkylating agent Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). Alkylating agents are reagents for effectin ...

.{{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

References

Organobromides Propargyl compounds

Applications and production

Reactions

Safety

See also

References