N-(2,3-Dichloro­phen­yl)-2,2,2-trimethyl­acetamide

The conformation of the N—H bond in the title compound (23DCPTMA), C₁₁H₁₃Cl₂NO, is syn to both the 2-chloro and the 3-chloro groups, similar to that in N-(2,3-dichloro­phen­yl)­acetamide (23DCPA), but in contrast to the anti conformation with respect to the 3-chloro substituent in N-(3-chloro­phen­yl)-2,2,2-trimethyl­acetamide (3CPTMA). The bond parameters of 23DCPTMA are similar to those in 3CPTMA, 23DCPA and other acetanilides. The mol­ecules in 23DCPTMA are linked into chains through N—H...O hydrogen bonding.

Key indicators

• Single-crystal X-ray study
• T = 299 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.061
• wR factor = 0.176
• Data-to-parameter ratio = 15.9

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT052_ALERT_1_A (Proper) Absorption Correction Method Missing ..          ?
PLAT057_ALERT_3_A Correction for Absorption Required   RT(exp) ...       1.66

Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C4
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C12
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          5

   2 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

As part of a study of the effect of ring and side chain substitutions on the solid state structures of aromatic amides (Gowda et al., 2007a,b), the crystal structure of N-(2,3-dichlorophenyl)-2,2,2-trimethylacetamide (23DCPTMA) has been determined. The conformation of the N—H bond in 23DCPTMA is syn to both the 2-chloro and 3-chloro groups (Fig. 1), similar to that in N-(2,3-dichlorophenyl)-acetamide (23DCPA)(Gowda et al., 2007b), but in contrast to the anti conformation with respect to the 3-chloro substituent in N-(3-chlorophenyl)- 2,2,2-trimethylacetamide (3CPTMA) (Gowda et al., 2007a). Intermolecular N—H···O hydrogen bonds (Table 1) link the molecules into chains (Fig. 2).

Related literature

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

S2. Experimental

The title compound was prepared according to a 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 by slow evaporation of an ethanolic solution (2 g in about 30 ml e thanol) and used for the X-ray diffraction study at room temperature.

S3. Refinement

All H atoms were positioned geometrically and refined as riding with C—H = 0.93–0.96 Å and N—H = 0.86 Å; U_iso(H) = 1.2U_eq(C,N).

Computing details

Data collection: CAD-4-PC Software (Enraf–Nonius, 1996); cell refinement: CAD-4-PC Software; data reduction: REDU4 (Stoe & Cie, 1987); 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.

Figures

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

N-(2,3-Dichlorophenyl)-2,2,2-trimethylacetamide

Crystal data

C11H13Cl2NO	F(000) = 512
Mr = 246.12	Dx = 1.333 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: -P 2ybc	Cell parameters from 24 reflections
a = 11.206 (3) Å	θ = 5.7–19.5°
b = 11.139 (3) Å	µ = 4.55 mm^−1
c = 10.075 (2) Å	T = 299 K
β = 102.70 (3)°	Rod, colourless
V = 1226.8 (5) Å^3	0.60 × 0.30 × 0.20 mm
Z = 4

Data collection

Enraf–Nonius CAD-4 diffractometer	1680 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.029
Graphite monochromator	θmax = 66.9°, θmin = 4.0°
ω/2θ scans	h = −13→13
Absorption correction: ψ scan (North et al., 1968)	k = −3→13
Tmin = 0.264, Tmax = 0.402	l = 0→12
2957 measured reflections	3 standard reflections every 120 min
2174 independent reflections	intensity decay: 1.0%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.061	H-atom parameters constrained
wR(F^2) = 0.176	w = 1/[σ^2(Fo^2) + (0.1081P)^2 + 0.276P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max = 0.001
2174 reflections	Δρmax = 0.30 e Å^−3
137 parameters	Δρmin = −0.50 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0058 (11)

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
Cl14	1.22112 (9)	0.32462 (14)	0.47441 (15)	0.1266 (6)
Cl15	0.99510 (9)	0.17412 (8)	0.51766 (9)	0.0841 (4)
O6	0.7204 (2)	0.2107 (2)	0.15772 (18)	0.0698 (6)
N7	0.7557 (2)	0.2709 (2)	0.3746 (2)	0.0570 (6)
H7N	0.7322	0.2703	0.4503	0.068*
C1	0.6547 (4)	0.0286 (4)	0.4031 (4)	0.1053 (14)
H1A	0.5933	−0.0254	0.4209	0.126*
H1B	0.6931	0.0687	0.4858	0.126*
H1C	0.7151	−0.0159	0.3691	0.126*
C2	0.5355 (3)	0.0561 (3)	0.1681 (3)	0.0802 (10)
H2A	0.5961	0.0112	0.1351	0.096*
H2B	0.4982	0.1136	0.1007	0.096*
H2C	0.4741	0.0023	0.1864	0.096*
C3	0.5000 (4)	0.1915 (4)	0.3513 (5)	0.0960 (13)
H3A	0.4383	0.1376	0.3686	0.115*
H3B	0.4630	0.2499	0.2848	0.115*
H3C	0.5382	0.2315	0.4341	0.115*
C4	0.5956 (2)	0.1210 (2)	0.2978 (3)	0.0525 (6)
C5	0.6947 (2)	0.2046 (2)	0.2697 (2)	0.0466 (6)
C8	0.8579 (2)	0.3419 (2)	0.3625 (2)	0.0537 (7)
C9	0.8410 (3)	0.4482 (3)	0.2922 (3)	0.0674 (8)
H9	0.7623	0.4743	0.2531	0.081*
C10	0.9402 (4)	0.5161 (3)	0.2796 (3)	0.0816 (10)
H10	0.9282	0.5883	0.2322	0.098*
C11	1.0561 (4)	0.4787 (3)	0.3358 (4)	0.0854 (11)
H11	1.1226	0.5252	0.3264	0.102*
C12	1.0746 (3)	0.3726 (3)	0.4063 (3)	0.0735 (9)
C13	0.9751 (3)	0.3034 (3)	0.4223 (3)	0.0586 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl14	0.0569 (5)	0.1743 (13)	0.1510 (12)	−0.0080 (6)	0.0279 (6)	−0.0386 (9)
Cl15	0.0899 (6)	0.0854 (6)	0.0783 (6)	0.0121 (4)	0.0208 (4)	0.0081 (4)
O6	0.0851 (14)	0.0934 (15)	0.0356 (9)	−0.0323 (12)	0.0234 (9)	−0.0110 (9)
N7	0.0609 (12)	0.0793 (15)	0.0333 (10)	−0.0228 (11)	0.0158 (9)	−0.0086 (9)
C1	0.109 (3)	0.097 (3)	0.098 (3)	−0.031 (2)	0.000 (2)	0.045 (2)
C2	0.079 (2)	0.094 (2)	0.0668 (19)	−0.0310 (18)	0.0145 (16)	−0.0173 (17)
C3	0.078 (2)	0.095 (3)	0.131 (3)	−0.0221 (19)	0.059 (2)	−0.034 (2)
C4	0.0542 (13)	0.0578 (15)	0.0476 (13)	−0.0097 (11)	0.0155 (11)	−0.0023 (11)
C5	0.0488 (12)	0.0558 (14)	0.0361 (12)	−0.0020 (10)	0.0114 (9)	−0.0021 (9)
C8	0.0606 (15)	0.0651 (16)	0.0375 (12)	−0.0170 (12)	0.0157 (11)	−0.0112 (11)
C9	0.082 (2)	0.0704 (18)	0.0499 (14)	−0.0113 (15)	0.0140 (13)	−0.0026 (13)
C10	0.117 (3)	0.071 (2)	0.0636 (18)	−0.029 (2)	0.0357 (19)	−0.0050 (15)
C11	0.095 (3)	0.091 (3)	0.084 (2)	−0.046 (2)	0.049 (2)	−0.0300 (19)
C12	0.0599 (16)	0.096 (2)	0.0704 (19)	−0.0200 (16)	0.0268 (14)	−0.0292 (17)
C13	0.0625 (16)	0.0688 (17)	0.0480 (14)	−0.0087 (12)	0.0201 (12)	−0.0150 (12)

Geometric parameters (Å, º)

Cl14—C12	1.720 (4)	C3—C4	1.519 (4)
Cl15—C13	1.719 (3)	C3—H3A	0.9600
O6—C5	1.226 (3)	C3—H3B	0.9600
N7—C5	1.346 (3)	C3—H3C	0.9600
N7—C8	1.419 (3)	C4—C5	1.523 (3)
N7—H7N	0.8600	C8—C9	1.371 (4)
C1—C4	1.522 (4)	C8—C13	1.387 (4)
C1—H1A	0.9600	C9—C10	1.374 (5)
C1—H1B	0.9600	C9—H9	0.9300
C1—H1C	0.9600	C10—C11	1.362 (6)
C2—C4	1.516 (4)	C10—H10	0.9300
C2—H2A	0.9600	C11—C12	1.371 (5)
C2—H2B	0.9600	C11—H11	0.9300
C2—H2C	0.9600	C12—C13	1.393 (4)
C5—N7—C8	121.2 (2)	C2—C4—C5	109.6 (2)
C5—N7—H7N	119.4	C3—C4—C5	110.5 (2)
C8—N7—H7N	119.4	C1—C4—C5	108.7 (2)
C4—C1—H1A	109.5	O6—C5—N7	120.6 (2)
C4—C1—H1B	109.5	O6—C5—C4	122.3 (2)
H1A—C1—H1B	109.5	N7—C5—C4	117.0 (2)
C4—C1—H1C	109.5	C9—C8—C13	120.1 (3)
H1A—C1—H1C	109.5	C9—C8—N7	120.2 (3)
H1B—C1—H1C	109.5	C13—C8—N7	119.7 (2)
C4—C2—H2A	109.5	C8—C9—C10	120.0 (3)
C4—C2—H2B	109.5	C8—C9—H9	120.0
H2A—C2—H2B	109.5	C10—C9—H9	120.0
C4—C2—H2C	109.5	C11—C10—C9	120.7 (4)
H2A—C2—H2C	109.5	C11—C10—H10	119.7
H2B—C2—H2C	109.5	C9—C10—H10	119.7
C4—C3—H3A	109.5	C10—C11—C12	120.0 (3)
C4—C3—H3B	109.5	C10—C11—H11	120.0
H3A—C3—H3B	109.5	C12—C11—H11	120.0
C4—C3—H3C	109.5	C11—C12—C13	120.2 (3)
H3A—C3—H3C	109.5	C11—C12—Cl14	119.8 (3)
H3B—C3—H3C	109.5	C13—C12—Cl14	120.0 (3)
C2—C4—C3	109.8 (3)	C8—C13—C12	119.0 (3)
C2—C4—C1	108.7 (3)	C8—C13—Cl15	119.8 (2)
C3—C4—C1	109.6 (3)	C12—C13—Cl15	121.3 (3)
C8—N7—C5—O6	−5.4 (4)	C8—C9—C10—C11	0.3 (5)
C8—N7—C5—C4	173.3 (2)	C9—C10—C11—C12	−0.3 (5)
C2—C4—C5—O6	−2.5 (4)	C10—C11—C12—C13	−0.8 (5)
C3—C4—C5—O6	−123.5 (3)	C10—C11—C12—Cl14	178.8 (3)
C1—C4—C5—O6	116.2 (3)	C9—C8—C13—C12	−1.8 (4)
C2—C4—C5—N7	178.8 (3)	N7—C8—C13—C12	178.3 (2)
C3—C4—C5—N7	57.8 (4)	C9—C8—C13—Cl15	176.6 (2)
C1—C4—C5—N7	−62.5 (4)	N7—C8—C13—Cl15	−3.3 (3)
C5—N7—C8—C9	75.9 (4)	C11—C12—C13—C8	1.9 (4)
C5—N7—C8—C13	−104.3 (3)	Cl14—C12—C13—C8	−177.8 (2)
C13—C8—C9—C10	0.8 (4)	C11—C12—C13—Cl15	−176.5 (2)
N7—C8—C9—C10	−179.4 (3)	Cl14—C12—C13—Cl15	3.8 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N7—H7N···O6^i	0.86	2.13	2.972 (3)	165

Symmetry code: (i) x, −y+1/2, z+1/2.