Aminorex (Menocil, Apiquel, aminoxaphen, aminoxafen, McN-742) is an anorectic stimulant drug of the 2-amino-5-aryl oxazoline class developed by a team at McNeil in 1962. It is closely related to 4-methylaminorex. Aminorex has been shown to have locomotor stimulant effects, lying midway between dextroamphetamine and methamphetamine. Aminorex effects have been attributed to the release of catecholamines. The drug has been retired from the market after it was found to result in pulmonary hypertension.

It was discovered in 1962 by Edward John Hurlburt (U.S. Patent 3,115,494), and was quickly found in 1963 to have an anorectic effect in rats. It was introduced as a prescription appetite suppressant in Germany, Switzerland and Austria in 1965, but was withdrawn in 1972 after it was found to cause pulmonary hypertension in approximately 0.2% of patients, and was linked to a number of deaths.

The synthesis was first reported in a structure-activity relationship study of 2-amino-5-aryl-2-oxazolines, where aminorex was found to be approximately 2.5 times more potent than D-amphetamine sulfate in inducing anorexia in rats, and was also reported to have CNS stimulant effects. This racemic synthesis involved an addition/cyclization reaction of 2-amino-1-phenylethanol with cyanogen bromide (mechanism shown below). A similar synthesis has been also published.