Investigation of interactions of ortho- and para-N-aryl-substituted 2-trifluoromethylcinnamanilides

Unsubstituted (2E)-N-phenyl-3-[2-(trifluoromethyl)phenyl]prop-2-enamide and six other ortho- or para-halogen-substituted anilides of 2-(trifluoromethyl)cinnamic acid were prepared. As the benzene nucleus of cinnamic acid itself is substituted in C₍₂₎ position with a trifluoromethyl moiety that is spatially close to both the amide bond and the halogen (F, Cl, CF₃) ortho-substitution of the anilide ring, interesting intramolecular interactions can be expected. Other derivatives are substituted at the para-position of the anilide ring, so that intermolecular interactions can be expected. Thus, it can be assumed that the predicted properties, especially lipophilicity, will differ significantly from the experimentally determined values. All the discussed compounds were analyzed using the reversed-phase high performance liquid chromatography method. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using an end-capped non-polar C₁₈ stationary reversed-phase column. In the present study, the structure-lipophilicity relationships of the studied compounds are discussed.