2,2-Dichloro-N-(3,4-dimethyl­phen­yl)acetamide

Abstract

In the title compound, C₁₀H₁₁Cl₂NO, the N—H bond is syn to the 3-methyl substituent in the aromatic ring, similar to that observed in N-(3,4-dimethyl­phen­yl)acetamide and to the 3-chloro substituent in 2,2-dichloro-N-(3,4-dichloro­phen­yl)acetamide, and contrasting with the anti conformation observed for the 3-methyl substituent in 2,2,2-trichloro-N-(3,4-dimethyl­phen­yl)acetamide. On the other hand, it is anti to the C=O bond. An inter­molecular N—H⋯O hydrogen bond links mol­ecules into infinite chains along the b axis.

Related literature

For the preparation of the compound, see: Shilpa & Gowda (2007 ▶). For related structures, see: Gowda et al. (2007 ▶, 2008 ▶, 2009 ▶)

Experimental

Crystal data

• C₁₀H₁₁Cl₂NO

• M _r = 232.10

• Monoclinic,

• a = 11.951 (1) Å

• b = 10.534 (1) Å

• c = 9.303 (1) Å

• β = 111.26 (1)°

• V = 1091.5 (2) ų

• Z = 4

• Mo Kα radiation

• μ = 0.56 mm⁻¹

• T = 299 K

• 0.28 × 0.20 × 0.12 mm

Data collection

• Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector

• Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007 ▶) T _min = 0.859, T _max = 0.936

• 4567 measured reflections

• 2214 independent reflections

• 1495 reflections with I > 2σ(I)

• R _int = 0.020

Refinement

• R[F ² > 2σ(F ²)] = 0.056

• wR(F ²) = 0.187

• S = 1.20

• 2214 reflections

• 144 parameters

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

• Δρ_max = 0.32 e Å⁻³

• Δρ_min = −0.37 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2004 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2007 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); 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	0.84 (4)	2.07 (4)	2.894 (3)	166 (3)

Symmetry code: (i) .

supplementary crystallographic information

Comment

As part of a study of the effect of ring and side chain substitutions on the crystal structures of aromatic amides (Gowda et al., 2007; 2008; 2009), the structure of 2,2-dichloro-N-(3,4-dimethylphenyl)acetamide (I) has been determined. The conformation of the N—H bond in the title compound is syn to the 3-methyl substituent in the aromatic ring [ similar to that observed in N-(3,4-dimethylphenyl)acetamide (Gowda et al., 2008) and to the 3-chloro substituent in 2,2-dichloro-N- (3,4-dichlorophenyl)-acetamide (Gowda et al., 2007)], and contrasting the anti conformation observed for the 3-methyl substituent in 2,2,2-trichloro-N-(3,4-dimethylphenyl)acetamide (Gowda et al., 2009). On the other hand, it is anti to the C=O bond, as observed in other amides. A N—H···O intermolecular hydrogen bond links molecules into infinite chains along the b axis. (Table 1, Fig. 2).

Experimental

Compound (I) was prepared and characterized according to the literature method (Shilpa and Gowda, 2007). Single crystals were obtained from the slow evaporation of an ethanolic solution of (I).

Refinement

The H atoms of the methyl groups were positioned with idealized geometry using a riding model [C—H = 0.96 Å]. The other H atoms were located in difference map and their positional parameters were refined freely [N—H = 0.84 (4) Å and C—H = 0.87 (4)–0.97 (4) Å]. All H atoms were refined with isotropic displacement parameters (set to 1.2 times of the U_eq of the parent atom).

Figures

Fig. 1.

Molecular structure of (I), showing the atom labelling scheme. The displacement ellipsoids are drawn at the 50% probability level.

Fig. 2.

Molecular packing of (I) with hydrogen bonding shown as dashed lines.

Crystal data

C10H11Cl2NO	F(000) = 480
Mr = 232.10	Dx = 1.412 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1463 reflections
a = 11.951 (1) Å	θ = 2.6–27.9°
b = 10.534 (1) Å	µ = 0.56 mm−1
c = 9.303 (1) Å	T = 299 K
β = 111.26 (1)°	Prism, colourless
V = 1091.5 (2) Å3	0.28 × 0.20 × 0.12 mm
Z = 4

Data collection

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector	2214 independent reflections
Radiation source: fine-focus sealed tube	1495 reflections with I > 2σ(I)
graphite	Rint = 0.020
Rotation method data acquisition using ω and φ scans	θmax = 26.4°, θmin = 2.7°
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007)	h = −14→13
Tmin = 0.859, Tmax = 0.936	k = −13→6
4567 measured reflections	l = −11→11

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.187	H atoms treated by a mixture of independent and constrained refinement
S = 1.20	w = 1/[σ2(Fo2) + (0.1P)2] where P = (Fo2 + 2Fc2)/3
2214 reflections	(Δ/σ)max = 0.023
144 parameters	Δρmax = 0.32 e Å−3
0 restraints	Δρmin = −0.37 e Å−3

Special details

Experimental. CrysAlis RED (Oxford Diffraction, 2007) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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
Cl1	−0.02466 (12)	0.39913 (11)	0.15433 (13)	0.0798 (4)
Cl2	−0.11319 (10)	0.15743 (13)	0.00649 (16)	0.0885 (5)
O1	0.1417 (2)	0.1762 (2)	0.2797 (2)	0.0521 (7)
N1	0.1947 (2)	0.1901 (3)	0.0686 (3)	0.0389 (6)
H1N	0.173 (3)	0.217 (3)	−0.023 (4)	0.047*
C1	0.3132 (3)	0.1393 (3)	0.1286 (3)	0.0360 (7)
C2	0.3945 (3)	0.1829 (3)	0.0644 (3)	0.0383 (7)
H2	0.370 (3)	0.240 (3)	−0.020 (4)	0.046*
C3	0.5126 (3)	0.1407 (3)	0.1172 (4)	0.0400 (7)
C4	0.5503 (3)	0.0526 (3)	0.2372 (4)	0.0442 (8)
C5	0.4666 (3)	0.0078 (3)	0.2959 (4)	0.0493 (9)
H5	0.487 (3)	−0.050 (4)	0.367 (4)	0.059*
C6	0.3489 (3)	0.0492 (3)	0.2448 (4)	0.0439 (8)
H6	0.295 (3)	0.013 (3)	0.284 (4)	0.053*
C7	0.1210 (3)	0.2076 (3)	0.1455 (3)	0.0384 (7)
C8	0.0029 (3)	0.2709 (4)	0.0500 (4)	0.0481 (8)
H8	−0.003 (3)	0.302 (4)	−0.051 (4)	0.058*
C9	0.5985 (3)	0.1928 (4)	0.0464 (5)	0.0580 (10)
H9A	0.6372	0.1238	0.0153	0.070*
H9B	0.6580	0.2442	0.1209	0.070*
H9C	0.5550	0.2435	−0.0420	0.070*
C10	0.6786 (3)	0.0066 (4)	0.3023 (5)	0.0664 (11)
H10A	0.7313	0.0774	0.3425	0.080*
H10B	0.6986	−0.0336	0.2221	0.080*
H10C	0.6876	−0.0532	0.3835	0.080*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cl1	0.0971 (9)	0.0780 (8)	0.0699 (7)	0.0313 (6)	0.0370 (6)	−0.0031 (5)
Cl2	0.0435 (6)	0.1112 (10)	0.1088 (10)	−0.0225 (6)	0.0251 (6)	−0.0137 (8)
O1	0.0568 (15)	0.0711 (16)	0.0349 (12)	0.0059 (12)	0.0246 (11)	0.0034 (11)
N1	0.0367 (14)	0.0520 (16)	0.0303 (13)	−0.0016 (12)	0.0147 (11)	0.0027 (12)
C1	0.0375 (16)	0.0395 (16)	0.0341 (15)	−0.0027 (13)	0.0167 (13)	−0.0061 (13)
C2	0.0411 (18)	0.0404 (17)	0.0348 (15)	0.0007 (13)	0.0154 (14)	0.0031 (13)
C3	0.0377 (17)	0.0404 (17)	0.0442 (17)	0.0008 (13)	0.0174 (15)	−0.0070 (14)
C4	0.0420 (18)	0.0405 (17)	0.0447 (17)	0.0050 (14)	0.0092 (15)	−0.0068 (15)
C5	0.061 (2)	0.0444 (19)	0.0425 (18)	0.0087 (17)	0.0188 (17)	0.0064 (16)
C6	0.051 (2)	0.0427 (18)	0.0412 (17)	−0.0029 (15)	0.0208 (15)	0.0018 (15)
C7	0.0385 (17)	0.0451 (17)	0.0352 (16)	−0.0079 (14)	0.0176 (13)	−0.0056 (14)
C8	0.0407 (18)	0.065 (2)	0.0426 (18)	−0.0003 (16)	0.0199 (15)	−0.0017 (17)
C9	0.044 (2)	0.059 (2)	0.082 (3)	0.0034 (16)	0.036 (2)	0.0025 (19)
C10	0.052 (2)	0.068 (3)	0.069 (2)	0.0146 (19)	0.011 (2)	0.001 (2)

Geometric parameters (Å, °)

Cl1—C8	1.763 (4)	C4—C10	1.510 (5)
Cl2—C8	1.763 (4)	C5—C6	1.382 (5)
O1—C7	1.227 (4)	C5—H5	0.87 (4)
N1—C7	1.334 (4)	C6—H6	0.93 (4)
N1—C1	1.425 (4)	C7—C8	1.522 (5)
N1—H1N	0.84 (4)	C8—H8	0.97 (4)
C1—C6	1.384 (4)	C9—H9A	0.9600
C1—C2	1.390 (4)	C9—H9B	0.9600
C2—C3	1.389 (4)	C9—H9C	0.9600
C2—H2	0.95 (3)	C10—H10A	0.9600
C3—C4	1.395 (5)	C10—H10B	0.9600
C3—C9	1.510 (5)	C10—H10C	0.9600
C4—C5	1.385 (5)
C7—N1—C1	126.7 (3)	O1—C7—N1	125.4 (3)
C7—N1—H1N	118 (2)	O1—C7—C8	121.0 (3)
C1—N1—H1N	115 (2)	N1—C7—C8	113.6 (3)
C6—C1—C2	119.8 (3)	C7—C8—Cl1	109.5 (2)
C6—C1—N1	123.0 (3)	C7—C8—Cl2	108.9 (3)
C2—C1—N1	117.2 (3)	Cl1—C8—Cl2	110.92 (18)
C3—C2—C1	121.4 (3)	C7—C8—H8	116 (2)
C3—C2—H2	118 (2)	Cl1—C8—H8	108 (2)
C1—C2—H2	121 (2)	Cl2—C8—H8	103 (2)
C2—C3—C4	119.2 (3)	C3—C9—H9A	109.5
C2—C3—C9	119.6 (3)	C3—C9—H9B	109.5
C4—C3—C9	121.2 (3)	H9A—C9—H9B	109.5
C5—C4—C3	118.2 (3)	C3—C9—H9C	109.5
C5—C4—C10	120.4 (3)	H9A—C9—H9C	109.5
C3—C4—C10	121.4 (3)	H9B—C9—H9C	109.5
C6—C5—C4	123.2 (3)	C4—C10—H10A	109.5
C6—C5—H5	117 (3)	C4—C10—H10B	109.5
C4—C5—H5	119 (3)	H10A—C10—H10B	109.5
C5—C6—C1	118.2 (3)	C4—C10—H10C	109.5
C5—C6—H6	120 (2)	H10A—C10—H10C	109.5
C1—C6—H6	122 (2)	H10B—C10—H10C	109.5
C7—N1—C1—C6	31.6 (5)	C10—C4—C5—C6	177.8 (3)
C7—N1—C1—C2	−149.1 (3)	C4—C5—C6—C1	0.4 (5)
C6—C1—C2—C3	−1.8 (5)	C2—C1—C6—C5	1.6 (5)
N1—C1—C2—C3	178.8 (3)	N1—C1—C6—C5	−179.1 (3)
C1—C2—C3—C4	0.0 (5)	C1—N1—C7—O1	−4.0 (5)
C1—C2—C3—C9	−178.6 (3)	C1—N1—C7—C8	176.7 (3)
C2—C3—C4—C5	2.0 (5)	O1—C7—C8—Cl1	50.4 (4)
C9—C3—C4—C5	−179.4 (3)	N1—C7—C8—Cl1	−130.4 (3)
C2—C3—C4—C10	−178.1 (3)	O1—C7—C8—Cl2	−71.0 (3)
C9—C3—C4—C10	0.5 (5)	N1—C7—C8—Cl2	108.2 (3)
C3—C4—C5—C6	−2.2 (5)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1i	0.84 (4)	2.07 (4)	2.894 (3)	166 (3)

Symmetry codes: (i) x, −y+1/2, z−1/2.