New efficient synthesis, spectroscopic characterization, and X-ray analysis of novel β-enaminocarboxamide derivatives

A new series of β-enaminocarboxamide was synthesized via the addition of chlorosulfonyl isocyanate to β-enaminones. The prepared intermediates were converted to corresponding β-enaminocarboxamides by removal of the chlorosulfonyl group using methanol. The resulting compounds were obtained in excellent yields in the range of (80–92%) and were characterized by 1 H, 13 C, HMBC, HSQC NMR spectroscopy, and IR spectroscopy as well as elemental analysis. 1 H-NMR spectrum showed a non-equivalence of the primary amide protons which was due to H-bonding. β-enaminocarboxamide 5h was obtained as a crystal and was subjected to X-ray analysis. Results showed that 5h crystallizes in the monoclinic crystal system with C2/c space group and the ORTEP confirmed the presence of intramolecular H-bonds.