Gomes, Ligia R.Low, John NicolsonCagide, FernandoBorges, Fernanda2019-10-242019-10-242015Gomes, L. R., Low, J. N., Cagide, F., & Borges, F. (2015). The crystal structures of four N-(4-halophen-yl)-4-oxo-4H-chromene-3-carboxamides. Acta crystallographica. Section E, Crystallographic communications, 71(Pt 1), 88–93. doi:10.1107/S20569890140270542056-9890http://hdl.handle.net/10284/8166Four N-(4-halophen­yl)-4-oxo-4H-chromene-3-carboxamides (halo = F, Cl, Br and I), N-(4-fluoro­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10FNO3, N-(4-chloro­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10ClNO3, N-(4-bromo­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10BrNO3, N-(4-iodo­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10INO3, have been structurally characterized. The mol­ecules are essentially planar and each exhibits an anti conformation with respect to the C—N rotamer of the amide and a cis geometry with respect to the relative positions of the Carom—Carom bond of the chromone ring and the carbonyl group of the amide. The structures each exhibit an intra­molecular hydrogen-bonding network comprising an N—H⋯O hydrogen bond between the amide N atom and the O atom of the carbonyl group of the pyrone ring, forming an S(6) ring, and a weak Carom—H⋯O inter­action with the O atom of the carbonyl group of the amide as acceptor, which forms another S(6) ring. All four compounds have the same supra­molecular structure, consisting of R 2 2(13) rings that are propagated along the a-axis direction by unit translation. There is π–π stacking involving inversion-related mol­ecules in each structure.engCrystal structureDrug designChromonesConformationSupra­molecular structurejournal article10.1107/S2056989014027054