2-Chloroethanol (also called ethylene chlorohydrin or glycol chlorohydrin) is an organic chemical compound with the chemical formula HOCH2CH2Cl and the simplestbeta-halohydrin (chlorohydrin).[6] This colorless liquid has a pleasant ether-like odor. It is miscible with water. The molecule is bifunctional, consisting of both an alkyl chloride and an alcoholfunctional group.[7]
2-Chloroethanol was once produced on a large scale as a precursor to ethylene oxide:
HOCH2CH2Cl + NaOH → C2H4O + NaCl + H2O
This application has been supplanted by the more economic direct oxidation of ethylene. Otherwise chloroethanol is still used in the production of pharmaceuticals, biocides, and plasticizers.[7] Many of these applications entail its use in installing 2-hydroxyethyl groups.[8] Several dyes are prepared by the alkylation of aniline derivatives with chloroethanol.[9] It is also used for manufacture of thiodiglycol.
Chloroethanol is a metabolite in the degradation of 1,2-dichloroethane. The alcohol is then further oxidized via chloroacetaldehyde to chloroacetate. This metabolic pathway is topical since billions of kilograms of 1,2-dichloroethane are processed annually as a precursor to vinyl chloride.[10]
Safety
2-Chloroethanol is toxic with an LD50 of 89 mg/kg in rats. Like most organochlorine compounds, chloroethanol releases hydrochloric acid and phosgene when burned.
^ abNomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: Royal Society of Chemistry. 2014. p. 29. doi:10.1039/9781849733069-FP001. ISBN978-0-85404-182-4. For example, the omission of the locant '1' in 2-chloroethanol, while permissible in general usage, is not allowed in preferred IUPAC names, thus the name 2-chloroethan-1-ol is the PIN.