Studies of hindered rotation and magnetic anisotropy by 1H, 19F and 13C NMR in models for drugs.: I.: The Diels-Alder adduct of phencyclone with N-2,2,2-trifluoroethylmaleimide, and precursors.

To gain understanding of hindered rotations and magnetic anisotropy in drugs, compounds of much intrinsic: importance, we have investigated as a model compound the Diels-Alder adduct of phenycyclone with (N) under bar-2,2,2-trifluoroethylmaleimide for study by H-1, F-19 and C-13 NMR. The (N) under bar-2,2,2-trifluoroethylmaleamic acid and maleimide precursors were examined by H-1 and F-19 NMR. phencyclone adduct is shown by H-1 and C-13 NMR (at 300 and 75 MHz, respectively) to exhibit slow exchange limit spectra at ambient temperatures, arising from hindered rotation of the bridgehead unsubstituted phenyl groups.