Observation of an infrequent enantiomer/conformer substitutional disorder in ethyl 13‐ethyl‐4‐oxo‐8,13‐dihydro‐4 H ‐benzo[5,6]azepino[3,2,1‐ ij ]quinoline‐5‐carboxylate heptane hemisolvate

Considering the importance of quinolones due to their broad spectrum of biological activities, the crystal structure of the title compound, C 22 H 21 NO 3 ·0.5C 7 H 16 , has been determined. Two enantiomers of the benzazepinoquinoline molecule and one molecule of heptane form the asymmetric unit of this centrosymmetric triclinic ( P ) crystal. All the molecules in the crystal present disorder. Substitutional disorder is observed for the benzazepine molecules, where a minority conformer of the R enantiomer replaces the main conformer of the S enantiomer and vice versa . Positional disorder is found for the heptane solvent molecule, which occupies a void left by the independent enantiomers of both conformers.