Francisco Javier Martínez-Martínez, Armando Ariza-Castolo, Hugo Tlahuext, Margarita Tlahuextl, Rosalinda Contreras, 1H, 13C, 15N, 2D and variable temperature NMR study of the role of hydrogen bonding in the structure and conformation of oxamide derivatives, J. Chem. Soc. Perkin Trans. 2, 1481-1485 (1993). DOI: 10.1039/P29930001481
The structure and conformation of N,N?-bis[(2-hydroxy)phenyl]oxamide (1); N,N?-bis[(2-methoxy)-phenyl]oxamide (2); N,N?-bis(phenyl)oxamide (3); N,N?-bis[(1R,2S)-()-norephedrine]oxamide (4); N,N?-bis[(1R,2R)-()-norpseudoephedrine]oxamide (5); N-[(2-hydroxy)phenyl]methylamide (6); N-[(2-methoxy)phenyl]methylamide (7); N-phenylmethylamide (8); N-[()-norephedrine]-methylamide (9) and N-[()-norpseudoephedrine]methylamide (10) were unambiguously established by 1H, 13C, 15N, 2D and variable temperature NMR spectroscopy. A careful NMR investigation of the conformational behaviour in these systems was relevant. It has been found that the dicarbonylic group in compounds 15 has a trans geometry, stabilized by intramolecular hydrogen bonding and that they possess a C2 axis. Compounds 1 and 2 are planar and compounds 1, 2, 4 and 5 present the amidic proton coordinated by two oxygen atoms.