General Description
Colorless to dark brown liquid. Sweet burning taste.
Reactivity Profile
2-BROMOETHANOL(540-51-2) forms an azeotrope with water; hydrolysis of aqueous solutions is accelerated by heat, alkalis and acids.
Air & Water Reactions
Hygroscopic. Water soluble.
Hazard
Irritant to eyes and mucous membranes.
Fire Hazard
This compound is combustible.
Description
2-bromoethanol, a halogenated alipathic hydrocarbon, is a widely used industrial chemical. It is also a contaminant in food such as wheat and flour during treatment with ethylene oxide. 2-Bromoethanol was also found as a metabolite of 1,2-dibromoethane. A known carcinogen in experimental animals. 2-Bromoethanol is highly toxic in vivo and is a potent mutagen. Fatty acid conjugates of 2-bromoethanol that have been identified after 2-bromoethanol administration to rats may explain the long term 2-bromoethanol accumulation and retention in body tissues. Chronic exposure to 2-bromoethanol causes liver and kidney toxicity. 2- Bromoethanol also induces extensive lipid peroxidation in rat liver, kidney and testis slices and inhibits liver mitochondria respiration[1].
Chemical Properties
colourless liquid
Uses
2-Bromoethanol is used in selective reduction of nitroarenes (PcFe(II)/NaBH4/2-bromoethanol catalyst system).
Uses
Ethylene bromohydrin is not used much forany commercial purpose. The risk of expo sure to this compound arises when ethyleneoxide reacts with hydrobromic acid.
Health Hazard
The vapors of ethylene bromohydrin are anirritant to the eyes and mucous membranes.It is corrosive to the skin. Ingestion of thiscompound can produce moderate to severetoxic effects. The target organs are the CNS,gastrointestinal tract, and liver. The lethaldose in mice by the intraperitoneal route was80 mg/kg.
Ethylene bromohydrin manifested car cinogenicity in test animals. It caused tumorsin lungs and the gastrointestinal tract in micefrom intraperitoneal (150 mg/kg/8 weeks)and oral (43 mg/kg/80 weeks) dosages,respectively. It is a mutagen, positive to thehistidine reversion–Ames test.
Synthesis
Ethylene gas is washed and passed into an ice-cold solution of 7.2 g of bromine in 500 ml water. After complete absorption of the bromine, a fresh portion of 7.2 g, equal to the first, is added, with frequent and vigorous agitation, until a total weight of 200 g of bromine has reacted. The lower layer of ethylene dibromide, formed during the process, is separated, washed with water, and dried over sodium sulfate. Yield, 88 g. After neutralizing with the sodium carbonate and saturating the aqueous layer with sodium chloride, the 2-bromoethanol is extracted by shaking twice with 100 ml of ether, dried over sodium sulfate; the ether is removed by evaporation yielding 85 g of bulk of the residual liquid, which distils between 145-149° C. 54.4% of the bromine is converted into 2-bromoethanol and 37.5% into ethylene dibromide. The remainder is found as hydrobromic acid.
Waste Disposal
Ethylene bromohydrin is mixed with a combustible solvent and burned in a chemicalincinerator.
References
[1] Sumsullah Khan, Peter J. O’Brien, Christian Sood. “The Involvement of Cytochrome P4502E1 in 2-Bromoethanol-Induced Hepatocyte Cytotoxicity.” Basic Clinical Pharmacology Toxicology 78 4 (1996): 241–248.
[2] L. Jenneskens, J. Ripoll, U. Wiersum. “Flash vacuum thermolysis of 2-bromoethanol. Formation of α-bromoethylethers via 1-bromoethanol.” Tetrahedron Letters 62 1 (1988): 6489–6491.
[3] L. Homanen, J. Murto. “Infrared-induced rotamerization of 2-bromoethanol and 2-iodoethanol in argon matrices.” Chemical Physics Letters 85 1 (1982): 322–324.
