Bromoethane

Bromoethane
Identifiers
CAS number 74-96-4 Y
ChemSpider 6092 Y
KEGG C19354 N
ChEMBL CHEMBL156378 Y
RTECS number KH6475000
Jmol-3D images Image 1
Properties
Molecular formula C2H5Br
Molar mass 108.97 g mol−1
Appearance Colorless liquid
Density 1.47 g/mL
Melting point

-119 °C, 154 K, -182 °F

Boiling point

38.4 °C, 312 K, 101 °F

Solubility in water 0.91 g/100 mL (20 °C)
Viscosity 0.402 cP at 20 °C
Hazards
EU classification Flammable (F)
Carc. Cat. 3
Harmful (Xn)
R-phrases R11 R20/22 R40
S-phrases (S2) S36/37
NFPA 704
1
2
0
Flash point −20 °C
Autoignition
temperature
511 °C
Explosive limits 6.8–11%
Related compounds
Related haloalkanes bromomethane
Chloroethane
Iodoethane
 N (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Bromoethane, also known as ethyl bromide, is a chemical compound of the haloalkanes group. It is abbreviated by chemists as EtBr. This volatile compound has an ether-like odour.

Contents

Preparation

The preparation of EtBr stands as a model for the synthesis of alkyl bromides in general. It is usually prepared by the addition of HBr to ethene:

H2C=CH2 + HBr → H3C-CH2Br

Ethyl bromide is inexpensive and would rarely be prepared in the laboratory. A laboratory synthesis include the reacting ethanol with a mixture of hydrobromic and sulfuric acids. An alternate route involves refluxing ethanol with phosphorus and bromine; phosphorus tribromide is generated in situ.[1]

Uses

In organic synthesis, EtBr is the synthetic equivalent of the ethyl carbocation (Et+) synthon.[2] In reality, such a cation is not actually formed. For example, carboxylates salts are converted to ethyl esters,[3] carbanions to ethylated derivatives, thiourea into ethylisothiouronium salts,[4] and amines into ethylamines.[5]

Safety

Halocarbons in general are potentially dangerous alkylating agents. Bromides are better alkylating agents than chlorides, thus exposure to EtBr should be minimized. EtBr is classified by the State of California as carcinogenic and a reproductive toxin.

References

External links