Carfilzomib Impurity 54

Chemical Name: Tert-butyl-((S)-1-(((S)-4-methyl-1-(((S)-1-(((S)-4-methyl-1-((R)-2-methyloxiran-2-yl)-1-oxopentan-2-yl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-1-oxopentan-2-yl)amino)-1-oxo-4-phenylbutan-2-yl)carbamate

Synonym: 3-Methyl formoterol (USP)

Smile: O=C([O-])N(C(C)(C)C)[C@@H](CCC1=CC=CC=C1)C(N[C@@H](CC(C)C)C(N[C@@H](CC2=CC=CC=C2)C(N[C@@H](CC(C)C)C([C@]3(C)OC3)=O)=O)=O)=O