Crystal Structures of N-[2-(4-oxo-4H-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

Abstract

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.