Ethylene Chlorohydrin

(also 2-chloroethyl alcohol), ClCH₂CH₂OH, a colorless liquid with a weak ethereal odor.

Ethylene chlorohydrin has a melting point of -67.5°C, a boiling point of 128.8°C, and a density of 1.202 g/cm³ at 20°C. Miscible in all proportions with water, it is soluble in most organic solvents. It forms an azeotropic mixture with water, toluene, and cyclohexane. The mixture with water, whose ethylene chlorohydrin content is 41 percent, has a boiling point of 98°C.

The most important property of ethylene chlorohydrin is its capacity to give up H⁺ and Cl^–, as described by the equation

This reaction, which was discovered by C. Wurtz in 1859, serves as the basis for a method of producing ethylene oxide. Ethylene chlorohydrin itself is produced industrially by the hypochlorination of ethylene according to the reaction

CH₂═CH₂ + Cl₂ + H₂)→C1CH₂CH₂OH + HCl

It is prepared in the laboratory by the addition of hydrogen chloride to ethylene oxide.

Ethylene chlorohydrin readily dissolves many organic substances, including cellulose acetate and ethylcellulose, but its use as a solvent is extremely limited because of its toxicity. The maximum permissible concentration of ethylene chlorohydrin vapor in the air is 0.5 mg/m³.