PENBUTOLOL IMPURITY A Penbutolol EP Impurity A Penbutolol Impurity 1 (Penbutolol EP Impurity A) (2S)-1-[2-(Cyclopent-1-enyl)phenoxy]-3-[(1,1-dimethylethyl)amino]propan-2-ol 2-Propanol, 1-[2-(1-cyclopenten-1-yl)phenoxy]-3-[(1,1-dimethylethyl)amino]-, (S)- (9CI)
