N-(3-Chloro-4-fluorophenyl)-2-(naphthalen-1-yl)acetamide

In the title compound, C18H13ClFNO, the dihedral angle between the mean planes of the chloro- and fluoro-substituted benzene ring and the naphthalene ring system is 60.5 (8)°. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, forming a zigzag chain along [101].

In the title compound, C 18 H 13 ClFNO, the dihedral angle between the mean planes of the chloro-and fluoro-substituted benzene ring and the naphthalene ring system is 60.5 (8) . In the crystal, molecules are linked by N-HÁ Á ÁO hydrogen bonds, forming a zigzag chain along [101].
ASP thanks the UOM for research facilities. BN thanks Mangalore University and the UGC SAP for financial assistance for the purchase of chemicals. JPJ acknowledges the NSF-MRI program (grant No. CHE1039027) for funds to purchase the X-ray diffractometer.

Experimental
Naphthalen-1-ylacetyl chloride (0.204 g, 1 mmol) and 3-chloro-4-fluoroaniline (0.145 g, 1 mmol) were dissolved in dichloromethane (20 mL). The mixture was stirred in presence of triethylamine at 273 K for about 3 h (Fig. 1). The contents were poured into 100 ml of ice-cold aqueous hydrochloric acid with stirring, which was extracted thrice with dichloromethane. Organic layer was washed with saturated NaHCO 3 solution and brine solution, dried and concentrated under reduced pressure to give the title compound (I). Single crystals were grown from toluene by the slow evaporation method (M.P.:

Refinement
The N-bound H atom was located in a difference Fourier map and refined isotropically with a distance restraint of N-H = 0.86 (2) Å. All of the remaining H atoms were placed in their calculated positions and then refined using the riding model, with C-H lengths of 0.95 Å (CH) or 0.99 Å (CH 2 ). Isotropic displacement parameters for these atoms were set to 1.19-1.21 (CH) or 1.20 (CH 2 ) times U eq of the parent atom.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 Rfactors(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.