Benzyl bromide is an organic compound with the formula C6H5CH2Br. The molecule consists of a benzene ring substituted with a bromomethyl group. It is a colorless liquid with lachrymatory properties. The compound is a reagent for introducing benzyl groups.[3][4]
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| Names | |||
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| Preferred IUPAC name
(Bromomethyl)benzene | |||
| Other names
α-Bromotoluene
Benzyl bromide | |||
| Identifiers | |||
3D model (JSmol)
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| ChemSpider | |||
| ECHA InfoCard | 100.002.589 | ||
PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |||
| C7H7Br | |||
| Molar mass | 171.037 g·mol−1 | ||
| Appearance | Colorless liquid | ||
| Odor | Sharp and pungent | ||
| Density | 1.438 g/cm3 | ||
| Melting point | −3.9 °C (25.0 °F; 269.2 K) | ||
| Boiling point | 201 °C (394 °F; 474 K) | ||
| Solubility | organic solvents | ||
| log P | 2.92[2] | ||
Refractive index (nD)
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1.5752 | ||
| Hazards | |||
| GHS labelling: | |||
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| Flash point | 70 °C (158 °F; 343 K) | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis and structure
editBenzyl bromide can be synthesized by the bromination of toluene under conditions suitable for a free radical halogenation:
The structure has been examined by electron diffraction.[5]
Applications
editBenzyl bromide is used in organic synthesis for the introduction of the benzyl groups when the less expensive benzyl chloride is insufficiently reactive.[6] [7] Benzylations are often achieved in the presence of catalytic amounts of sodium iodide, which generates the more reactive benzyl iodide in situ.[3] In some cases, benzyl serves as protecting group for alcohols and carboxylic acids.[8]
Safety
editBenzyl bromide is a strong lachrymator and is also intensely irritating to skin and mucous membranes. Because of these properties, it has been used in chemical warfare, both in combat and in training due to its irritating yet non-lethal nature.
See also
editReferences
edit- ^ Merck Index (11th ed.). p. 1142.
- ^ "Benzyl bromide_msds".
- ^ a b William E. Bauta (2001). "Benzyl Bromide". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rb047. ISBN 0-471-93623-5.
- ^ "Benzyl bromide". Sigma Aldrich. sigmaaldrich.com. Retrieved 8 June 2017.
- ^ Vilkov, L. V.; Sadova, N. I. (March 1976). "Electron diffraction study on the molecular structure of benzyl chloride and benzyl bromide in the vapour phase". Journal of Molecular Structure. 31 (1): 131–142. Bibcode:1976JMoSt..31..131S. doi:10.1016/0022-2860(76)80124-X.
- ^ Andrew G. Myers; Bryant H. Yang (2000). "Synthesis and Diastereoselective Alkylation of Pseudoephenedrine Amides". Org. Synth. 77: 22. doi:10.15227/orgsyn.077.0022.
- ^ Harry Heaney; Steven V. Ley (1974). "1-Benzylindole". Org. Synth. 54: 58. doi:10.15227/orgsyn.054.0058.
- ^ "Benzyl bromide". chemicalbook.com. Retrieved 8 June 2017.