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.[2]

Propargyl bromide may be produced by the treatment of propargyl alcohol with phosphorus tribromide.[3]

Reactions

Propargyl bromide is an alkylating agent. For example, it reacts with dimethylsulfide, it reacts to give the sulfonium salt:[4]

HCCCH2Br + S(CH3)2 → [HCCCH2S(CH3)2]Br

It alkylates even weakly basic amines such as aniline.[5]

Aldehydes react with propargyl bromide in a Barbier-type reaction to yield alkynyl alcohols:[6]

Barbier reaction

At low temperatures, upon treatment with magnesium, propargyl bromide gives the Grignard reagent formally derived from allenyl bromide, i.e., CH2=C=CHMgBr.[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]

See also

References

  1. ^ a b c d e f Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  2. ^ 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
  3. ^ "Process for Producing Propargyl Bromide". Retrieved November 7, 2012.
  4. ^ P. D. Howes, C. J. M. Stirling (1973). "3-Acetyl-2,4-Dimethylfuran". Organic Syntheses. 53: 1. doi:10.15227/orgsyn.053.0001.
  5. ^ Yu Chen, Anton Dubrovskiy, Richard C. Larock (2012). "Synthesis of Quinolines by Electrophilic Cyclization of N-(2-Alkynyl)Anilines: 3-Iodo-4-Phenylquinoline". Organic Syntheses. 89: 294. doi:10.15227/orgsyn.089.0294.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  6. ^ Jõgi, Artur; Mäeorg, Uno (30 November 2001). "Zn Mediated Regioselective Barbier Reaction of Propargylic Bromides in THF/aq. NH
    4    Cl     Solution"    . Molecules. 6 (12): 964–968. doi:10.3390/61200964.
  7. ^ Henning Hopf, Ingrid Böhm, and Jürgen Kleinschroth (1990). "Diels-Alder Reaction of 1,2,4,5-Hexatetraene: Tetramethyl[2.2]paracyclophane-4,5,12,13-tetracarboxylate". Organic Syntheses. 60: 41{{cite journal}}: CS1 maint: multiple names: authors list (link); Collected Volumes, vol. 7, p. 485.
  8. ^ "3-Bromo-1-Propyne". Retrieved November 3, 2012.
  9. ^ Urben, P.G., ed. (2017). "C1". Bretherick's Handbook of Reactive Chemical Hazards. pp. 81–882. doi:10.1016/B978-0-08-100971-0.00055-X. ISBN 978-0-08-100971-0.
Allikas: https://en.wikipedia.org/wiki/Propargyl_bromide
No tags for this post.