1-Bromobutane

1-Bromobutane is the organobromine compound with the formula CH3(CH2)3Br. It is a colorless liquid, although impure samples appear yellowish. It is insoluble in water, but soluble in organic solvents. It is a primarily used as a source of the butyl group in organic synthesis. It is one of several isomers of butyl bromide.

1-Bromobutane
Names
IUPAC name
1-Bromobutane[1]
Other names
Butyl bromide
Identifiers
3D model (JSmol)
1098260
ChEMBL
ChemSpider
ECHA InfoCard 100.003.357
EC Number
  • 203-691-9
MeSH butyl+bromide
RTECS number
  • EJ6225000
UNII
UN number 1126
Properties
C4H9Br
Molar mass 137.020 g·mol−1
Appearance Colourless liquid
Density 1.2676 g mL−1
Melting point −112.5 °C; −170.4 °F; 160.7 K
Boiling point 101.4 to 102.9 °C; 214.4 to 217.1 °F; 374.5 to 376.0 K
log P 2.828
Vapor pressure 5.3 kPa
140 nmol Pa kg−1
1.439
Thermochemistry
162.2 J K−1 mol−1
327.02 J K−1 mol−1
−148 kJ mol−1
−2.7178–−2.7152 MJ mol−1
Hazards
GHS pictograms
GHS Signal word Danger
H225, H315, H319, H335, H411
P210, P261, P273, P305+351+338
Flash point 10 °C (50 °F; 283 K)
265 °C (509 °F; 538 K)
Explosive limits 2.8–6.6%
Lethal dose or concentration (LD, LC):
2.761 g kg−1 (oral, rat)
Related compounds
Related alkanes
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Synthesis

Most 1-bromoalkanes are prepared by free-radical addition of hydrogen bromide to the 1-alkene. These conditions lead to the anti-Markovnikov addition, i.e. give the 1-bromo derivatives.[2]

1-Bromobutane can also be prepared from butanol by treatment with hydrobromic acid:[3]

CH3(CH2)3OH + HBr → CH3(CH2)3Br + H2O

Reactions

As a primary haloalkane, it is prone to SN2 type reactions. It is commonly used as an alkylating agent. When combined with magnesium metal in dry ether, it gives the corresponding Grignard reagent. Such reagents are used to attach butyl groups to various substrates.

1-Bromobutane is the precursor to n-butyllithium:[4]

2 Li + C4H9X → C4H9Li + LiX
where X = Cl, Br

The lithium for this reaction contains 1-3% sodium. When bromobutane is the precursor, the product is a homogeneous solution, consisting of a mixed cluster containing both LiBr and LiBu.

References
  1. "butyl bromide - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 27 March 2005. Identification. Retrieved 17 June 2012.
  2. Dagani, M. J.; Barda, H. J.; Benya, T. J.; Sanders, D. C. "Bromine Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a04_405.
  3. Oliver Kamm, C. S. Marvel, R. H. Goshorn, Thomas Boyd, And E. F. Degering "Alkyl And Alkylene Bromides" Org. Synth. 1921, volume 1, p. 3. doi:10.15227/orgsyn.001.0003
  4. Brandsma, L.; Verkraijsse, H. D. (1987). Preparative Polar Organometallic Chemistry I. Berlin: Springer-Verlag. ISBN 3-540-16916-4.
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