Bromoethane

Structural formula
General
Surname	Bromoethane
other names	Ethyl bromide
Molecular formula	C 2 H 5 Br
Brief description	colorless, highly refractive liquid with an ethereal odor
External identifiers / databases
EC number	200-825-8
ECHA InfoCard	100,000,751
PubChem	6332
Wikidata	Q412245
properties
Molar mass	108.97 g mol −1
Physical state	liquid
density	1.46 g cm −3 (20 ° C)
Melting point	−119 ° C
boiling point	38 ° C
Vapor pressure	513 hPa (20 ° C)
solubility	heavy in water (9 g l −1 at 20 ° C)
Refractive index	1.4239 (20 ° C)
safety instructions
H and P phrases	H: 225-302 + 332-351
	P: 210-261-304 + 340 + 312-370 + 378-403 + 235-502
MAK	Switzerland: 5 ml m −3 or 22 mg m −3
Toxicological data	1350 mg kg −1 ( LD 50 , rat , oral )
Thermodynamic properties
ΔH f 0	−90.5 kJ / mol
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Bromethane (also ethyl bromide , abbr .: EtBr ) is a bromine derivative of ethane and thus a haloalkane . It must not be confused with bromomethane (CH ₃ Br).

presentation

In the laboratory , bromoethane can be prepared by reacting ethanol with phosphorus tribromide PBr ₃ . Phosphonic acid PH (OH) ₂ O is formed as a by-product .

{\ displaystyle \ mathrm {3 \ CH_ {3} -CH_ {2} -OH + PBr_ {3} \ rightleftharpoons 3 \ CH_ {3} -CH_ {2} -Br + H_ {3} PO_ {3}}}

properties

At room temperature, bromoethane is a colorless to yellowish liquid whose vapors are heavier than air. Bromoethane vapors form flammable, explosive mixtures with air.

When heated, it decomposes with the formation of ethene and hydrogen bromide.

The neighboring carbon atom is positively polarized by the electronegative bromine. Thus, bromoethane acts as an electrophilic reagent in many chemical reactions .

use

Bromethane is used in many ways in organic chemical synthesis, especially for the introduction of ethyl groups into organic compounds. In Grignard reactions , the ethyl group of the bromoethane is " reversed " into a carbon nucleophile , which opens up a number of other synthetic applications.

It used to be used for anesthetic purposes.

safety instructions

Skin contact, inhalation and ingestion of bromoethane is harmful. The eyes, respiratory organs and skin are strongly irritated by bromoethane. Liver, lung and kidney damage are possible when absorbed through the skin. The carcinogenic effect of bromoethane has been clearly demonstrated in animal experiments. Bromethane also has a narcotic effect.

Others

The abbreviation EtBr for bromoethane, which is often found in publications, goes back to the internationally recognized abbreviation Et for the ethyl group. In the bioscientific fields this can lead to confusion, because there EtBr is used as the short form for the phenanthridine dye ethidium bromide , which is used as a detection reagent for nucleic acids .

Individual evidence

↑ ^a ^b ^c ^d Entry on bromoethane. In: Römpp Online . Georg Thieme Verlag, accessed on September 29, 2014.
↑ ^a ^b ^c ^d ^e ^f ^g Entry on bromoethane in the GESTIS substance database of the IFA , accessed on July 23, 2016(JavaScript required) .
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-62.
↑ Entry on bromoethanes in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 74-96-4 or bromoethane ), accessed on November 2, 2015.
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-22.

[roempp-1] Entry on bromoethane. In: Römpp Online . Georg Thieme Verlag, accessed on September 29, 2014.

[GESTIS-2] ↑ ^a ^b ^c ^d ^e ^f ^g Entry on bromoethane in the GESTIS substance database of the IFA , accessed on July 23, 2016(JavaScript required) .

[CRC90_3_62-3] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-62.

[CLP_100.000.751-4] Entry on bromoethanes in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[5] Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 74-96-4 or bromoethane ), accessed on November 2, 2015.

[CRC90_5_22-6] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-22.