1,1′-[(1-Methylethyl)imino]bis[3-[4-(2-methoxyethyl)phenoxy]-2-propanol hydrochloride;3,3'-(isopropylazanediyl)bis(1-(4-(2-methoxyethyl)phenoxy)propan -2-ol) hydrochloride;Metoprolol impurity 12/Metoprolol EP Impurity O HCl/Metoprolol USP Related Compound D HCl/3,3'-(isopropylazanediyl)bis(1-(4-(2-methoxyethyl)phenoxy)propan -2-ol) hydrochloride;3,3'-(isopropylazanediyl)bis(1-(4-(2-methoxyethyl);Metoprolol-12;1-[[2-hydroxy-3-[4-(2-methoxyethyl)phenoxy]propyl]-propan-2-ylamino]-3-[4-(2-methoxyethyl)phenoxy]propan-2-ol;Metoprolol Impurity O HCl;Metoprolol Related compound D HCl