2-Chloro-N-(2-chloro­phen­yl)acetamide

The conformation of the N—H bond in the structure of the title compound, C₈H₇Cl₂NO, is syn to the ortho-Cl substituent of the aromatic ring, similar to that observed in 2-chloro-N-(2-nitro­phen­yl)acetamide, N-(2-chloro­phen­yl)acetamide and N-(2-chloro­phen­yl)-2,2,2-trimethyl­acetamide. The bond parameters in these compounds have similar values. The mol­ecules are packed into columns and are connected through N—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.011 Å
• R factor = 0.091
• wR factor = 0.247
• Data-to-parameter ratio = 15.8

checkCIF/PLATON results

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S1. Comment

In the present work, as part of a study of the substituent effects on the structures of N-aromatic amides, the structure of N-(2-chlorophenyl)- 2-chloroacetamide has been determined (Gowda et al., 2007; Gowda et al., 2007a, b). The conformation of the N—H bond in the structure is syn to the ortho-Cl substituent in the aniline ring (Fig. 1), similar to that observed in N-(2-nitrophenyl)-2-chloroacetamide (Gowda et al., 2007), N-(2-chlorophenyl)-acetamide (Gowda et al., 2007b) and N-(2-chlorophenyl)-2,2,2-trimethylacetamide (Gowda et al., 2007a). The packing diagram molecules shows the hydrogen bonds N1—H1N···O1 (Table 1) linking the molecules into chains (Fig. 2).

Related literature

For related literature, see: Gowda et al. (2003, 2007, 2007a,b).

S2. Experimental

The title compound was prepared according to the literature method (Gowda et al., 2003). The purity of the compound was checked by determining its melting point. It was characterized by recording its infrared and NMR spectra (Gowda et al., 2003). Single crystals of the title compound were obtained from an ethanolic solution and used for X-ray diffraction studies at room temperature.

S3. Refinement

The crystal was a non-merohedral twin (twin law: -1 0 0/0 - 1 0/0.18 0 1) and the contribution of the major domain refined to 0.201 (9). All H atoms were positioned geometrically and treated as riding atoms (C—H = 0.95–0.99 Å, N—H = 0.88 Å), with the U_iso(H) values set at 1.2 U_eq of the parent atom.

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2007); cell refinement: CrysAlis RED (Oxford Diffraction, 2007); data reduction: CrysAlis RED (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures

	Fig. 1. Molecular structure of the title compound, showing the atom labeling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radius.
	Fig. 2. Molecular packing and hydrogen bonding in the title compound. Hydrogen bonds are shown as dashed lines.

2-Chloro-N-(2-chlorophenyl)acetamide

Crystal data

C8H7Cl2NO	F(000) = 416
Mr = 204.05	Dx = 1.577 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1759 reflections
a = 4.7699 (7) Å	θ = 2.3–27.3°
b = 10.859 (2) Å	µ = 0.70 mm^−1
c = 16.599 (3) Å	T = 100 K
β = 91.48 (2)°	Needle, colourless
V = 859.5 (3) Å^3	0.50 × 0.18 × 0.12 mm
Z = 4

Data collection

Oxford Diffraction Xcalibur diffractometer with Sapphire CCD detector	1742 independent reflections
Radiation source: fine-focus sealed tube	1588 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
Rotation method data acquisition using ω and phi scans.	θmax = 26.4°, θmin = 2.2°
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007)	h = −5→5
Tmin = 0.733, Tmax = 0.881	k = −13→13
4931 measured reflections	l = 0→20

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.091	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.247	H-atom parameters constrained
S = 1.30	w = 1/[σ^2(Fo^2) + (0.029P)^2 + 13.468P] where P = (Fo^2 + 2Fc^2)/3
1742 reflections	(Δ/σ)max = 0.001
110 parameters	Δρmax = 0.86 e Å^−3
0 restraints	Δρmin = −0.66 e Å^−3

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² 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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.4183 (16)	−0.0268 (7)	0.3652 (4)	0.0156 (15)
C2	0.5352 (15)	−0.0816 (8)	0.2978 (4)	0.0167 (16)
C3	0.4611 (17)	−0.2001 (8)	0.2746 (5)	0.0203 (17)
H3	0.5443	−0.2368	0.2291	0.024*
C4	0.2656 (17)	−0.2647 (7)	0.3180 (5)	0.0195 (16)
H4	0.2095	−0.3450	0.3015	0.023*
C5	0.1513 (18)	−0.2108 (7)	0.3863 (5)	0.0206 (17)
H5	0.0210	−0.2560	0.4170	0.025*
C6	0.2254 (17)	−0.0925 (7)	0.4099 (4)	0.0188 (16)
H6	0.1454	−0.0566	0.4562	0.023*
C7	0.3208 (15)	0.1831 (7)	0.4107 (4)	0.0137 (15)
C8	0.4655 (17)	0.3052 (7)	0.4315 (5)	0.0210 (17)
H8A	0.6088	0.3230	0.3910	0.025*
H8B	0.5619	0.2981	0.4848	0.025*
N1	0.4995 (13)	0.0955 (6)	0.3881 (4)	0.0185 (14)
H1N	0.6789	0.1142	0.3873	0.022*
O1	0.0686 (11)	0.1699 (5)	0.4149 (3)	0.0190 (12)
Cl1	0.7771 (4)	−0.00167 (17)	0.24183 (10)	0.0177 (5)
Cl2	0.2236 (4)	0.42742 (19)	0.43354 (14)	0.0277 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.013 (4)	0.014 (4)	0.020 (4)	0.001 (3)	−0.003 (3)	0.004 (3)
C2	0.008 (3)	0.024 (4)	0.018 (4)	0.002 (3)	0.002 (3)	0.001 (3)
C3	0.016 (4)	0.018 (4)	0.027 (4)	−0.002 (3)	0.000 (3)	−0.004 (3)
C4	0.021 (4)	0.012 (3)	0.025 (4)	0.000 (3)	−0.005 (3)	0.005 (3)
C5	0.018 (4)	0.019 (4)	0.025 (4)	−0.004 (3)	0.002 (3)	0.003 (3)
C6	0.019 (4)	0.026 (4)	0.011 (3)	0.003 (3)	0.002 (3)	0.004 (3)
C7	0.011 (4)	0.022 (4)	0.007 (3)	−0.003 (3)	0.000 (3)	−0.003 (3)
C8	0.014 (4)	0.017 (4)	0.032 (4)	0.001 (3)	0.000 (3)	0.002 (3)
N1	0.005 (3)	0.025 (4)	0.026 (3)	0.001 (3)	0.001 (2)	−0.002 (3)
O1	0.008 (3)	0.023 (3)	0.026 (3)	0.001 (2)	0.000 (2)	0.000 (2)
Cl1	0.0175 (9)	0.0189 (9)	0.0168 (8)	−0.0018 (8)	0.0048 (6)	0.0009 (7)
Cl2	0.0190 (10)	0.0190 (10)	0.0450 (13)	0.0038 (8)	−0.0022 (9)	−0.0097 (9)

Geometric parameters (Å, º)

C1—C6	1.394 (11)	C5—H5	0.9500
C1—C2	1.396 (11)	C6—H6	0.9500
C1—N1	1.433 (10)	C7—O1	1.216 (9)
C2—C3	1.386 (11)	C7—N1	1.337 (10)
C2—Cl1	1.732 (8)	C7—C8	1.530 (11)
C3—C4	1.384 (11)	C8—Cl2	1.759 (8)
C3—H3	0.9500	C8—H8A	0.9900
C4—C5	1.400 (11)	C8—H8B	0.9900
C4—H4	0.9500	N1—H1N	0.8800
C5—C6	1.386 (11)
C6—C1—C2	119.5 (7)	C5—C6—C1	119.4 (7)
C6—C1—N1	120.7 (7)	C5—C6—H6	120.3
C2—C1—N1	119.8 (7)	C1—C6—H6	120.3
C3—C2—C1	120.9 (7)	O1—C7—N1	124.8 (7)
C3—C2—Cl1	119.0 (6)	O1—C7—C8	122.0 (7)
C1—C2—Cl1	120.1 (6)	N1—C7—C8	113.1 (6)
C4—C3—C2	119.8 (8)	C7—C8—Cl2	111.5 (5)
C4—C3—H3	120.1	C7—C8—H8A	109.3
C2—C3—H3	120.1	Cl2—C8—H8A	109.3
C3—C4—C5	119.4 (7)	C7—C8—H8B	109.3
C3—C4—H4	120.3	Cl2—C8—H8B	109.3
C5—C4—H4	120.3	H8A—C8—H8B	108.0
C6—C5—C4	121.0 (7)	C7—N1—C1	124.4 (6)
C6—C5—H5	119.5	C7—N1—H1N	117.8
C4—C5—H5	119.5	C1—N1—H1N	117.8
C6—C1—C2—C3	0.3 (11)	C2—C1—C6—C5	−0.5 (11)
N1—C1—C2—C3	179.7 (7)	N1—C1—C6—C5	−179.9 (7)
C6—C1—C2—Cl1	−179.6 (6)	O1—C7—C8—Cl2	−16.4 (9)
N1—C1—C2—Cl1	−0.2 (10)	N1—C7—C8—Cl2	163.7 (5)
C1—C2—C3—C4	1.0 (12)	O1—C7—N1—C1	0.4 (12)
Cl1—C2—C3—C4	−179.2 (6)	C8—C7—N1—C1	−179.7 (7)
C2—C3—C4—C5	−2.0 (12)	C6—C1—N1—C7	−44.3 (11)
C3—C4—C5—C6	1.7 (12)	C2—C1—N1—C7	136.3 (8)
C4—C5—C6—C1	−0.5 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1^i	0.88	2.00	2.856 (8)	165

Symmetry code: (i) x+1, y, z.