4-(2-하이드록시에틸)-피페라진-2-ONE4-(2-hydroxyethyl)-2-Piperazinone4-(2-Hydroxyethyl)-piperazin-2-one2-Piperazinone, 4-(2-hydroxyethyl)-4-(2-hydroxyethyl)-2-piperazin-4-iumoneN-Nitroso-4-(2-hydroxyethyl)-piperazin-2-oneN-Nitroso-4-(2-hydroxyethyl)-piperazin-2-one in acetonitrile