Cytostatics. 19. Configurative assignment of diastereomer N,N'-dialkyl-alpha ,alpha '-diphenylethylenediamines by nuclear resonance spectroscopy

Abstract

The assignment of the configuration of o-R1C6H4CH(NHR)CH(NHR)C6H4R1-o (I; R = H, Bu, or Me2CHCH2; R1 = H or Cl) by PMR used the different chem. shifts of the ethylene protons (alpha -H) and arom. protons. The meso form exhibited a paramagnetic shift for the arom. protons and a diamagnetic shift for alpha -H compared to the racemic form. Corresponding differences were obsd. in the spectra of the cis and trans forms of II (X = S or H2), prepd. by reaction of I with CS2 or HCHO, resp. In contrast to I the signals of the arom. H of the cis forms of II were situated at higher field and the alpha -H signals at lower field compared to the trans forms owing to the different interactions between arom. rings. and the alpha -protons.