N-(4-Chlorophenyl)-4-methoxy-3-(propanamido)benzamide cyclohexane hemisolvate

The title compound, C17H17ClN2O3·0.5C6H12, was prepared by the condensation reaction of 4-methoxy-3-(propanamido)benzoic acid with 4-chloroaniline. The Cl atom, the propionyl CH3 group and the cyclohexyl CH2 group are disordered over two sets of sites of equal occupancy in both molecules. The cyclohexane solvent molecule is disordered over two orientations which were modelled with relative occupancies of 0.484 (4) and 0.516 (4). In the crystal, there are a number of N—H⋯O hydrogen bonds, forming layers perpendicular to (001).

In the molecule of the title compound (I), there are two crystallographically independent benzamide molecules and one cyclohexane molecule in the asymmetric unit. The chlorine, the propionyl CH 3 and cyclohexyl CH 2 are disordered. The isotropic displacement parameters of Cl1 (0.1177), Cl2 (0.1153), C16A (0.123) and C16B (0.156) are slightly higher than the average equivalent isotropic displacement parameters (0.065). No restraints were used. The occupancies of Cl1, Cl2, C16A and C16B are all equal to 1. The cyclohexane is disordered having two orientations which have been modelled with relative occupancies of 0.484 (4):0.516 (4). The dihedral angle between the benzene rings in molecule A is 7. 86 (25) and this is very similar to that found in molecule B [7.76 (25)]. In the crystal structure, there are a number of N-H···O hydrogen bonds forming layers which are perpendicular to (001). (Table1, Fig. 1).

Refinement
All H atoms were placed at calculated positions C-H = 0.93-0.97 Å and N-H = 0.86 Å, and were included in the final cycles of refinement using a riding model, with Uiso(H) = 1.2Ueq(C,N) or 1.5 Ueq(methyl C). The absolute structure cannot be determined reliably.

Figure 1
The molecular structure of (I), showing 40% probability displacement ellipsoids and the atom-numbering scheme.
Hydrogen atoms have been omitted for clarity.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.