organic compounds
Two polymorphs of N-(2-methoxyphenyl)-4-oxo-4H-chromone-3-carboxamide crystallise in the monoclinic space group P21/c, each with two molecules in the asymmetric unit. The conformations of all four molecules are similar, the main differences being in their supramolecular interactions.
organic compounds
The structures of 4-oxo-N-phenyl-4H-chromene-2-carboxamide and of a new polymorph of 7-methoxy-4-oxo-N-p-tolyl-4H-chromene-2-carboxamide and its hemihydrate. The structures have an anti-rotamer conformation about the C-N bond; however, the amide O atom can be either trans- or cis-related to the O atom of the pyran ring.