Lisinopril Impurity 8

N2-((S)-1-Ethoxy-1-oxo-4-phenylbutan-2-yl)-N6-(2,2,2-trifluoroacetyl)-L-lysyl-L-proline; L-Proline, N2-[(1S)-1-(ethoxycarbonyl)-3-phenylpropyl]-N6-(2,2,2-trifluoroacetyl)-L-lysyl; L-Proline, 1-[N2-[1-(ethoxycarbonyl)-3-phenylpropyl]-N6-(trifluoroacetyl)-L-lysyl]-, (S); N2-[(1S)-1-(Ethoxycarbonyl)-3-phenylpropyl]-N6-(2,2,2-trifluoroacetyl)-L-lysyl-L-proline; N2-[(S)-1-Ethoxycarbonyl-3-phenylpropyl]-N6-trifluoroacetyl-L-lysyl-L-proline;