Ethylnorepinephrine (also known as Ethylnoradrenaline, butanephrine, E.N.S., 4-(2-Amino-1-hydroxybutyl)-1,2-benzenediol, E.N.E, α-(1-Aminopropyl)-3,4-dihydroxybenzyl alcohol, (+-)-Ethylnorepinephrine, lennrxojhwnhsd-uhfffaoysa-n, Etanor;Butanephrine or (+/-)-Ethylnorepinephrine) is a sympathomimetic substance of the phenylethanolamine class.