2-Methylpropanoicacid 5-(2-((1,1-dimethylethyl)amino)-1-hydroxy ethyl)-1,3-phenylene ester 5-(2-(tert-Butylamino)-1-hydroxyethyl)-m-phenylene diisobutyrate 53034-85-8 EINECS 258-311-4 Ibuterol Ibuterol [INN] Ibuterolum [INN-Latin] KWD 2058 Terbutalindiisobutyrat