Procaterol (also known as 72332-33-3, Procaterolo, (R,S)-(-)-8-Hydroxy-5-(1-hydroxy-2-((1-methylethyl)amino)butyl)-2(1H)-quinolinone**, Spectrum2_001550, Spectrum3_001770, 2(1H)-Quinolinone, 8-hydroxy-5-(1-hydroxy-2-((1-methylethyl)amino)butyl)-, 8-Hydroxy-5-(1-hydroxy-2-((1-methylethyl)amino)butyl)-2(1H)-quinolinone, BSPBio_003239, SPBio_001400 or GTPL3464) is a substance of the phenylethanolamine class.