2-Chloro-N-(2,3-dichloro­phen­yl)acetamide

Abstract

The conformation of the N—H bond in the title compound (23DCPCA), C₈H₆Cl₃NO, is syn to both the 2- and 3-chloro substituents in the aromatic ring, similar to the 2-chloro substituent in 2-chloro-N-(2-chloro­phen­yl)acetamide (2CPCA), the 2- and 3-chloro substituents in N-(2,3-dichloro­phen­yl)acetamide (23DCPA) and in 2,2-dichloro-N-(2,3-dichloro­phen­yl)acetamide (23DCPDCA). The bond parameters in 23DCPCA are similar to those in 2-chloro-N-(phen­yl)acetamide, 2CPCA, 23DCPA, 23DCPDCA and other acetanilides. The mol­ecules in 23DCPCA are linked into chains through N—H⋯O hydrogen bonding.

Related literature

For related literature, see: Gowda et al. (2007a ▶,b ▶,c ▶); Shilpa & Gowda (2007 ▶).

Experimental

Crystal data

• C₈H₆Cl₃NO

• M _r = 238.49

• Monoclinic,

• a = 11.704 (3) Å

• b = 4.712 (1) Å

• c = 17.503 (4) Å

• β = 99.76 (2)°

• V = 951.3 (4) ų

• Z = 4

• Cu Kα radiation

• μ = 8.38 mm⁻¹

• T = 299 (2) K

• 0.50 × 0.35 × 0.28 mm

Data collection

• Enraf–Nonius CAD-4 diffractometer

• Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.014, T _max = 0.096

• 1832 measured reflections

• 1692 independent reflections

• 1625 reflections with I > 2σ(I)

• R _int = 0.036

• 3 standard reflections frequency: 120 min intensity decay: 2.0%

Refinement

• R[F ² > 2σ(F ²)] = 0.080

• wR(F ²) = 0.231

• S = 1.07

• 1692 reflections

• 122 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.87 e Å⁻³

• Δρ_min = −1.04 e Å⁻³

Data collection: CAD-4-PC (Enraf–Nonius, 1996 ▶); cell refinement: CAD-4-PC; data reduction: REDU4 (Stoe & Cie, 1987 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2003 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O1i	0.85 (5)	2.05 (5)	2.862 (4)	161 (4)

Symmetry code: (i) .

supplementary crystallographic information

Comment

In the present work, the structure of 2-chloro-N-(2,3-dichlorophenyl)- acetamide (23DCPCA) has been determined to study the effect of substituents on the structures of N-aromatic amides (Gowda et al., 2007a, b, c). The conformation of the N—H bond in 23DCPCA is syn to both the 2-chloro and 3-chloro substituent (Fig. 1), similar to that of 2-chloro substituent in 2-chloro-N-(2-chlorophenyl)acetamide (2CPCA)(Gowda et al., 2007b), 2- and 3-chloro substituents in N-(2,3-dichlorophenyl)-acetamide (23DCPA) (Gowda et al., 2007a) and in 2,2-dichloro-N-(2,3-dichlorophenyl)acetamide (23DCPDCA)(Gowda et al., 2007c). The bond parameters in 23DCPCA are similar to those in 2-chloro-N-(phenyl)acetamide, 2CPCA, 23DCPA, 23DCPDCA and other acetanilides (Gowda et al., 2007a, b, c). The molecules in the structure of 23DCPCA are stabilized through N—H···O hydrogen bonding (Table 1 and Fig.2).

Experimental

The title compound was prepared according to the literature method (Shilpa & Gowda, 2007). The purity of the compound was checked by determining its melting point. It was characterized by recording its infrared and NMR spectra (Shilpa & Gowda, 2007). Single crystals of the title compound were obtained from an ethanolic solution and used for X-ray diffraction studies at room temperature.

Refinement

The CH atoms were positioned with idealized geometry using a riding model with C—H = 0.93–0.97 Å. The NH atom was located in difference map with N—H = 0.85 (5) Å. U_iso(H) values were set equal to 1.2 U_eq of the parent atom.

The residual electron-density features are located in the region of Cl1. The highest peak and deepest hole are 1.04 and 0.80%A from Cl1, respectively.

Figures

Fig. 1.

Molecular structure of the title compound, showing the atom labeling scheme. The displacement ellipsoids are drawn at the 50% probability level.

Fig. 2.

Molecular packing of the title compound with hydrogen bonding shown as dashed lines.

Crystal data

C8H6Cl3NO	F000 = 480
Mr = 238.49	Dx = 1.665 Mg m−3
Monoclinic, P21/n	Cu Kα radiation λ = 1.54180 Å
Hall symbol: -P 2yn	Cell parameters from 25 reflections
a = 11.704 (3) Å	θ = 4.3–23.9º
b = 4.712 (1) Å	µ = 8.38 mm−1
c = 17.503 (4) Å	T = 299 (2) K
β = 99.76 (2)º	Prism, colourless
V = 951.3 (4) Å3	0.50 × 0.35 × 0.28 mm
Z = 4

Data collection

Enraf–Nonius CAD-4 diffractometer	Rint = 0.036
Radiation source: fine-focus sealed tube	θmax = 66.9º
Monochromator: graphite	θmin = 4.2º
T = 299(2) K	h = −13→1
ω/2θ scans	k = −5→0
Absorption correction: ψ scan(North et al., 1968)	l = −20→20
Tmin = 0.014, Tmax = 0.096	3 standard reflections
1832 measured reflections	every 120 min
1692 independent reflections	intensity decay: 2.0%
1625 reflections with I > 2σ(I)

Refinement

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.080	w = 1/[σ2(Fo2) + (0.181P)2 + 0.9328P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.231	(Δ/σ)max = 0.025
S = 1.07	Δρmax = 0.87 e Å−3
1692 reflections	Δρmin = −1.04 e Å−3
122 parameters	Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.018 (3)
Secondary atom site location: difference Fourier map

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	0.4488 (3)	0.5307 (7)	0.36495 (19)	0.0315 (8)
C2	0.4556 (3)	0.4122 (7)	0.2935 (2)	0.0316 (8)
C3	0.5442 (3)	0.4955 (9)	0.2544 (2)	0.0395 (9)
C4	0.6240 (4)	0.6936 (10)	0.2854 (3)	0.0502 (11)
H4	0.6825	0.7486	0.2586	0.060*
C5	0.6172 (4)	0.8099 (9)	0.3558 (3)	0.0502 (11)
H5	0.6714	0.9453	0.3768	0.060*
C6	0.5313 (3)	0.7298 (9)	0.3964 (2)	0.0416 (9)
H6	0.5284	0.8089	0.4447	0.050*
C7	0.2947 (4)	0.6252 (8)	0.4390 (2)	0.0376 (9)
C8	0.1935 (4)	0.4823 (8)	0.4667 (2)	0.0430 (10)
H8A	0.2178	0.2983	0.4884	0.052*
H8B	0.1320	0.4519	0.4228	0.052*
N1	0.3582 (3)	0.4477 (7)	0.40382 (17)	0.0347 (8)
H1N	0.346 (4)	0.271 (11)	0.405 (3)	0.042*
O1	0.3132 (3)	0.8774 (6)	0.4466 (2)	0.0556 (9)
Cl1	0.35541 (7)	0.16288 (19)	0.25447 (5)	0.0389 (5)
Cl2	0.55325 (12)	0.3482 (3)	0.16544 (7)	0.0653 (6)
Cl3	0.14026 (11)	0.6855 (3)	0.53663 (7)	0.0602 (5)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.0320 (17)	0.0313 (17)	0.0342 (16)	−0.0005 (13)	0.0143 (13)	0.0009 (13)
C2	0.0245 (16)	0.0345 (17)	0.0383 (18)	−0.0019 (13)	0.0126 (13)	0.0041 (14)
C3	0.0316 (17)	0.050 (2)	0.0428 (19)	0.0012 (16)	0.0234 (14)	0.0043 (16)
C4	0.034 (2)	0.056 (2)	0.067 (3)	−0.0074 (17)	0.0248 (19)	0.006 (2)
C5	0.033 (2)	0.049 (2)	0.070 (3)	−0.0125 (17)	0.0109 (19)	−0.0012 (19)
C6	0.040 (2)	0.045 (2)	0.042 (2)	−0.0058 (16)	0.0097 (16)	−0.0031 (16)
C7	0.050 (2)	0.0314 (18)	0.0354 (18)	−0.0010 (15)	0.0188 (16)	0.0010 (14)
C8	0.048 (2)	0.040 (2)	0.049 (2)	−0.0055 (16)	0.0304 (17)	−0.0054 (16)
N1	0.0431 (16)	0.0293 (15)	0.0376 (16)	−0.0022 (12)	0.0236 (13)	−0.0005 (12)
O1	0.074 (2)	0.0305 (15)	0.076 (2)	−0.0035 (13)	0.0499 (18)	−0.0054 (13)
Cl1	0.0360 (7)	0.0433 (7)	0.0411 (7)	−0.0057 (3)	0.0170 (4)	−0.0078 (3)
Cl2	0.0670 (9)	0.0878 (10)	0.0529 (8)	−0.0123 (6)	0.0438 (6)	−0.0074 (5)
Cl3	0.0646 (9)	0.0640 (9)	0.0639 (8)	−0.0105 (5)	0.0454 (6)	−0.0179 (5)

Geometric parameters (Å, °)

C1—C2	1.384 (5)	C5—H5	0.9300
C1—C6	1.391 (5)	C6—H6	0.9300
C1—N1	1.409 (4)	C7—O1	1.211 (5)
C2—C3	1.392 (5)	C7—N1	1.337 (5)
C2—Cl1	1.718 (3)	C7—C8	1.512 (5)
C3—C4	1.366 (6)	C8—Cl3	1.750 (4)
C3—Cl2	1.725 (4)	C8—H8A	0.9700
C4—C5	1.363 (7)	C8—H8B	0.9700
C4—H4	0.9300	N1—H1N	0.85 (5)
C5—C6	1.379 (6)
C2—C1—C6	119.2 (3)	C5—C6—C1	119.9 (4)
C2—C1—N1	119.2 (3)	C5—C6—H6	120.0
C6—C1—N1	121.7 (3)	C1—C6—H6	120.0
C1—C2—C3	119.5 (3)	O1—C7—N1	124.2 (4)
C1—C2—Cl1	119.7 (3)	O1—C7—C8	122.5 (4)
C3—C2—Cl1	120.8 (3)	N1—C7—C8	113.3 (3)
C4—C3—C2	120.9 (4)	C7—C8—Cl3	111.8 (3)
C4—C3—Cl2	119.4 (3)	C7—C8—H8A	109.3
C2—C3—Cl2	119.7 (3)	Cl3—C8—H8A	109.3
C5—C4—C3	119.5 (4)	C7—C8—H8B	109.3
C5—C4—H4	120.2	Cl3—C8—H8B	109.3
C3—C4—H4	120.2	H8A—C8—H8B	107.9
C4—C5—C6	121.0 (4)	C7—N1—C1	124.9 (3)
C4—C5—H5	119.5	C7—N1—H1N	119 (3)
C6—C5—H5	119.5	C1—N1—H1N	116 (3)
C6—C1—C2—C3	−0.3 (5)	C3—C4—C5—C6	0.2 (7)
N1—C1—C2—C3	179.3 (3)	C4—C5—C6—C1	−1.0 (7)
C6—C1—C2—Cl1	179.3 (3)	C2—C1—C6—C5	1.0 (6)
N1—C1—C2—Cl1	−1.1 (5)	N1—C1—C6—C5	−178.6 (4)
C1—C2—C3—C4	−0.4 (6)	O1—C7—C8—Cl3	−20.3 (5)
Cl1—C2—C3—C4	−180.0 (3)	N1—C7—C8—Cl3	161.7 (3)
C1—C2—C3—Cl2	179.9 (3)	O1—C7—N1—C1	−5.7 (6)
Cl1—C2—C3—Cl2	0.3 (5)	C8—C7—N1—C1	172.3 (3)
C2—C3—C4—C5	0.4 (6)	C2—C1—N1—C7	−135.6 (4)
Cl2—C3—C4—C5	−179.9 (3)	C6—C1—N1—C7	44.0 (5)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1i	0.85 (5)	2.05 (5)	2.862 (4)	161 (4)

Symmetry codes: (i) x, y−1, z.