3-Chloro-N-(4-methoxyphenyl)propanamide

The title compound, C10H12ClNO2, is a halogenated derivative of a secondary amide bearing an aromatic substituent. The C(=O)—N(H)—Car—Car torsion angle of −33.70 (18)° rules out the presence of resonance spanning the amide as well as the aromatic system. In the crystal, classical N—H⋯O hydrogen bonds, as well as C–H⋯O contacts connect the molecules into chains propagating along the a axis.

The title compound, C 10 H 12 ClNO 2 , is a halogenated derivative of a secondary amide bearing an aromatic substituent. The C( O)-N(H)-C ar -C ar torsion angle of À33.70 (18) rules out the presence of resonance spanning the amide as well as the aromatic system. In the crystal, classical N-HÁ Á ÁO hydrogen bonds, as well as C-HÁ Á ÁO contacts connect the molecules into chains propagating along the a axis.
The C=O bond length as well as the C(=O)-N(H) bond length of 1.2326 (14) Å and 1.3416 (15) Å, respectively, are indicative of typical amide-type resonance. The aromatic system of the phenyl moiety bonded to the amide's nitrogen atom, on the other hand, does not participate in this resonance as becomes apparent by the corresponding C(=O)-N(H)-C ar -C ar dihedral angle of -33.70 (18) ° (Fig. 1).
In the crystal, classical hydrogen bonds of the N-H···O type as well as C-H···O contacts whose range falls by more than 0.1 Å below the sum of van-der-Waals radii of the atoms participating are observed in form of two homodromic chains. The C-H···O contacts stem from the methylene group adjacent to the C=O group and -in combination with the nitrogen-bond hydrogen atom -chelate the oxygen atom of the amide functionality. In terms of graph-set analysis (Etter et al., 1990;Bernstein et al., 1995), the descriptor for the classical hydrogen bonds as well as the C-H···O contacts is each C 1 1 (4) on the unitary level. In total, the molecules are connected to chains along the crystallographic a axis. The shortest intercentroid distance between two centers of gravity was found at 4.8194 (8) Å (Fig. 2).
The packing of the title compound in the crystal is shown in Figure 3.

Experimental
The title compound was obtained from R. L. Fine Chem., Bengaluru, India. X-ray quality crystals were obtained from dichloromethane by slow evaporation at room temperature.

Refinement
Carbon-bound H atoms were placed in calculated positions (C-H 0.95 Å for aromatic carbon atoms and C-H 0.99 Å for methylene groups) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U eq (C). The H atoms of the methyl group were allowed to rotate with a fixed angle around the C-C bond to best fit the experimental supplementary materials sup-2 electron density (HFIX 137 in the SHELX program suite (Sheldrick, 2008), with U(H) set to 1.5U eq (C). The nitrogen-bound H atom was located on a difference Fourier map and refined freely. Fig. 1. The molecular structure of the title compound, with atom labels and anisotropic displacement ellipsoids (drawn at 50% probability level).