Ethylene Cyanohydrin

(also β-hydroxypropionitrile), HOCH₂CH₂CN, a colorless, viscous liquid.

Ethylene cyanohydrin has a melting point of –46°C, a boiling point of 227°–228°C (accompanied by decomposition), and a density of 1.040 g/cm³ at 25°C. It is miscible in all proportions with water, ethanol, ether, and acetone but is insoluble in benzene. It is a solvent for cellulose esters and some salts of inorganic acids.

Ethylene cyanohydrin is produced mainly by reacting ethylene oxide with hydrocyanic acid in the presence of catalytic amounts of sodium cyanide (NaCN) or another basic agent according to the reaction

It is used in the manufacture of such important products as acrylonitrile (by dehydration in the liquid or vapor phase) and acrylates (by the action of alcohols in the presence of dilute sulfuric acid).