Crystal Structures of N-[2-(4-oxo-4 H -benzo[ d ] [1, 3]-oxazin-2-yl)benzamide and Propionamide and Their N-Containing Analog N-[2-(4-oxo-3,4-dihydroquinazolin-2-yl)phenyl]propionamide

Specific features of the molecular and crystal structures of two substituted benzoxazinones ( I and II ) and their structural analog quinazolinone ( III ) have been analyzed by the XRD method. Compound I exists in two crystalline modifications. All investigated molecules are nonplanar; however, the character of their nonplanarity is different. In molecules I and II , the intramolecular hydrogen bond N–H⋅⋅⋅N rather than the potentially possible bond N–H⋅⋅⋅О is closed. Molecule III also contains the similar hydrogen bond. The occurrence of weak directional interactions in the crystal packings (π–π interactions in I and II and intermolecular hydrogen bonds N–Н⋅⋅⋅O in III ) leads to the formation of isolated dimer structures rather than infinite formations.