complete assignment of 1H, 13C and 19F NMR spectra of (2E)-N,N’-dibenzylbut-2-enediamide analogues.

Abstract

The complete 1H, 13C and 19F NMR spectral assignment with application of 2D led to the structural elucidation of two novel classes of butenediamide. The trans vinylic 1H-1H coupling constant of J = 15.80 Hz average indicates C = C presence, a doublet of a triplet observed at 8.95 ppm (J = 6.88 Hz) in the H1-NMR spectra was assigned to the NH of the two amide functional groups. Triplet peaks observed to be due to the collapse of two doublet peaks at 4.38 ppm with J = 5.94 Hz was assigned to the two methylene protons H-1’and H-1†which showed a cross peak correlation in COSY spectrum with both NH of the amide. The large coupling constant of J = 245 Hz average for Carbon bearing a Fluorine atom, with 19F NMR spectra peaks of -113 to -118 ppm also aid in elucidating the structures of 64 and 70.  Low resonating peaks at δ = 42 ppm for methylene carbon of benzyl rings was diagnostic in structural mapping. Keywords: 1H, 13C, 19F NMR, 2D-NMR, Chemical shifts, (2E)-N,N’-dibenzylbut-2-enediamide,