N-(3-Chloro-4-fluorophenyl)acetamide

In the title compound, C8H7ClFNO, the dihedral angle between the benzene ring and the acetamide side chain is 5.47 (6)°. An S(6) ring motif is formed via an intramolecular C—H⋯O hydrogen bond. In the crystal, N—H⋯O hydrogen bonds link the molecules into C(4) chains along [001].

In the title compound, C 8 H 7 ClFNO, the dihedral angle between the benzene ring and the acetamide side chain is 5.47 (6) . An S(6) ring motif is formed via an intramolecular C-HÁ Á ÁO hydrogen bond. In the crystal, N-HÁ Á ÁO hydrogen bonds link the molecules into C(4) chains along [001].

Comment
To complement earlier studies of acetamides (Khan et al., 2010;Tahir & Shad, 2011), we report herein the crystal structure of the title compound.

Experimental
3-Chloro-4-fluoro aniline (0.145 g, 1 mmol) was dissolved in acetic acid (20 mL) and refluxed for 4 h. The solution was then cooled and poured into 100 ml of ice-cold water with stirring. The precipitate obtained was filtered, washed with water and dried. Orange blocks were grown from DMF solution by the slow evaporation method. M. P.: 384 K.

Refinement
N-bound H atoms were located from the difference Fourier map and were refined with a riding model with U iso (H) = 1.2 U eq (N) [N-H = 0.9003 Å]. The remaining H atoms were positioned geometrically and refined with a riding model with U iso (H) = 1.2 or 1.5 U eq (C) [C-H = 0.95 or 0.98 Å]. A rotating group model was applied to the methyl groups. In the final refinement, five outliners were omitted, -3 8 2, -1 0 1, -3 8 1, 1 0 0 and -1 0 4. In the final difference Fourier map, the highest peak and the deepest hole are 0.83 and 0.71Å from atom Cl1.

Figure 2
The crystal packing of the title compound, viewed along the a axis, showing the chains along the c axis. H atoms not involved in the intermolecular interactions (dashed lines) have been omitted for clarity.

N-(3-Chloro-4-fluorophenyl)acetamide
Crystal data  (Cosier & Glazer, 1986) operating at 100.0 (1) K. 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq