2,2,2-Trichloro-N-(3-nitrophenyl)acetamide

In the title compound, C8H5Cl3N2O3, the dihedral angle between the nitrophenyl ring and the acetamide group is 5.47 (6)°. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds link the molecules into chains running parallel to the b axis.

In the title compound, C 8 H 5 Cl 3 N 2 O 3 , the dihedral angle between the nitrophenyl ring and the acetamide group is 5.47 (6) . In the crystal, N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds link the molecules into chains running parallel to the b axis.

Experimental
Data collection: SMART (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1998) (Bruker, 1998); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and CAMERON (Watkin et al., 1993); software used to prepare material for publication: WinGX (Farrugia, 1999  In view of earlier studies and interest owing to the biological activity of acetamide (Khan et al., 2010;Tahir & Shad, 2011), we report herein the crystal structure of the title compound. In the title compound, the nitro phenyl ring makes a dihedral angle of 5.47 (6)° with acetamide group. Bond lengths and angles are within the normal ranges and are comparable with a related structure (Rosli et al., 2007). In the crystal, an S(6) ring motif (Bernstein et al., 1995) is formed via intramolecular C8-H8A···O1 hydrogen bond (Table 1). The C-H···O and C-H···N hydrogen bonding intractions (Table 1 and Figure 2) result in bifurcated bonds and link the molecules into chains along the b-axis.

Experimental
3-Nitroaniline (1.0 g, 0.0072 mmol) was dissolved in 2M hydrochloric acid (5.0 ml), and added a little crushed ice. A solution of hydrated sodium acetate (5.0 g) in 25 ml of water was introduced, followed by trichloroacetic anhydride (4.5 g, 0.01457 mol). The mixture was shaken in the cold until the smell of trichloroacetic anhydride disappeared. The title compound was collected by filtration and recrystallized from an aqueous ethanol (75%) solution; yield: 1.52 g (75%), m.p. 376.15-378.15 K.

Refinement
The H atoms were placed at calculated positions in the riding model approximation with N-H = 0.86 and C-H = 0.93 Å, and U iso (H) = 1.2U eq (N/C).

Computing details
Data collection: SMART (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1998); data reduction: SAINT-Plus (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and CAMERON (Watkin et al., 1993); software used to prepare material for publication: WinGX (Farrugia, 1999   Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 C1 0.8599 (