Lactonitrile is a chemical compound used as a solvent and as an intermediate in the industrial production of ethyl lactate and lactic acid. It is the cyanohydrin derived from acetaldehyde. Lactonitrile is a chemical compound used as a solvent and as an intermediate in the industrial production of ethyl lactate and lactic acid. It is the cyanohydrin derived from acetaldehyde. Lactonitrile is obtained by reacting hydrogen cyanide with acetaldehyde.