N-(2-Chloro­phen­yl)-2,2,2-trimethyl­acetamide

The conformation of the N—H bond in the structure of the title compound, C₁₁H₁₄ClNO, is syn to the ortho-chloro substituent, similar to that in 2,2,2-trimethyl-N-(2-methyl­phen­yl)acetamide and the side-chain unsubstituted N-(2-chloro­phen­yl)acetamide, but in contrast with the anti conformation observed for N-(3-chloro­phen­yl)-2,2,2-trimethyl­acetamide. The bond parameters are also similar to those observed in related compounds and other acetanilides. The mol­ecules are linked into chains through N—H...O hydrogen bonding.

Key indicators

• Single-crystal X-ray study
• T = 302 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.049
• wR factor = 0.136
• Data-to-parameter ratio = 17.0

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT242_ALERT_2_B Check Low       Ueq as Compared to Neighbors for         C8

Alert level C
PLAT153_ALERT_1_C The su's on the Cell Axes   are Equal (x 100000)        100 Ang.
PLAT180_ALERT_3_C Check Cell Rounding: # of Values Ending with 0 =          3
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          6

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           26.37
           From the CIF: _reflns_number_total               2261
           Count of symmetry unique reflns         1369
           Completeness (_total/calc)            165.16%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       892
           Fraction of Friedel pairs measured     0.652
           Are heavy atom types Z>Si present        yes
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

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

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

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S1. Comment

The structure of N-(2-chlorophenyl)-2,2,2-trimethylacetamide (2CPTMA) has been determined as part of a study on the systematization of the crystal structures of N-aromatic amides (Gowda et al., 2007, 2007a,b). The conformation of the N—H bond in 2CPTMA is syn to the ortho-chloro substituent (Fig. 1), similar to that in N-(2-methylphenyl)-2,2,2-trimethylacetamide (2MPTMA) (Gowda et al., 2007a) and the side chain unsubstituted N-(2-chlorophenyl)-acetamide (2CPA), but in contrast to the anti conformation observed for the N-(3-chlorophenyl)-2,2,2-trimethylacetamide (3CPTMA) (Gowda et al., 2007). The geometric parameters of 2CPTMA are also similar to those of 2MPTMA, 2CPA, 3CPTMA and other acetanilides (Gowda et al., 2007, 2007a,b). The molecules in 2CPTMA are packed into chains in the direction of c axis through N—H···O hydrogen bonds (Fig. 2 & Table 1).

Related literature

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

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

All H atoms attached to C atoms were fixed geometrically and treated as riding with C—H = 0.93 Å (Caromatic) and 0.96 Å (Cmethyl) with U_iso(H) = 1.2U_eq(Caromatic) or U_iso(H) = 1.5U_eq(Cmethyl). H atom attached to N atom was located in difference Fourier maps and included in the subsequent refinement using restraint (N—H= 0.85 (1) Å) with U_iso(H) = 1.2U_eq(N).

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis RED (Oxford Diffraction, 2006); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. 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 radii.
	Fig. 2. Partial packing view showing the formation of the chain through N—H···O Hydrogen bonding. H atoms not involved in hydrogen bondings have been omitted for clarity. Hydrogen bonds are shown as dashed lines. [Symmetry code: (i) x - 1/2, 1/2 - y, 2 - z].

N-(2-Chlorophenyl)-2,2,2-trimethylacetamide

Crystal data

C11H14ClNO	F(000) = 448
Mr = 211.68	Dx = 1.220 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 1749 reflections
a = 10.159 (1) Å	θ = 2.7–20.5°
b = 10.248 (1) Å	µ = 0.30 mm^−1
c = 11.071 (1) Å	T = 302 K
V = 1152.6 (2) Å^3	Rod shape, colourless
Z = 4	0.60 × 0.16 × 0.14 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector	2261 independent reflections
Radiation source: Enhance (Mo) X-ray Source	1279 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.049
Detector resolution: 8.4012 pixels mm^-1	θmax = 26.4°, θmin = 2.7°
Rotation method data acquisition using ω and φ scans	h = −12→9
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2006) using a multifaceted crystal model (Clark & Reid, 1995)	k = −11→12
Tmin = 0.840, Tmax = 0.959	l = −10→13
6499 measured reflections

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)] = 0.049	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.136	w = 1/[σ^2(Fo^2) + (0.0688P)^2 + 0.003P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.002
2261 reflections	Δρmax = 0.37 e Å^−3
133 parameters	Δρmin = −0.24 e Å^−3
1 restraint	Absolute structure: Flack (1983), with 892 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.07 (13)

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	0.3757 (3)	0.1032 (3)	0.9165 (3)	0.0485 (9)
C2	0.3373 (3)	0.0764 (3)	0.7973 (3)	0.0529 (9)
C3	0.3577 (4)	−0.0442 (4)	0.7466 (4)	0.0701 (11)
H3	0.3290	−0.0615	0.6684	0.084*
C4	0.4203 (4)	−0.1384 (4)	0.8118 (4)	0.0790 (12)
H4	0.4354	−0.2197	0.7770	0.095*
C5	0.4610 (4)	−0.1155 (4)	0.9273 (5)	0.0776 (13)
H5	0.5042	−0.1805	0.9705	0.093*
C6	0.4375 (4)	0.0066 (3)	0.9809 (4)	0.0602 (10)
H6	0.4638	0.0219	1.0601	0.072*
C7	0.4429 (3)	0.3056 (3)	1.0162 (3)	0.0451 (7)
C8	0.3943 (3)	0.4347 (3)	1.0682 (3)	0.0533 (9)
C9	0.3016 (6)	0.4088 (4)	1.1719 (3)	0.1125 (19)
H9A	0.3464	0.3596	1.2331	0.169*
H9B	0.2271	0.3602	1.1434	0.169*
H9C	0.2723	0.4903	1.2052	0.169*
C10	0.3203 (5)	0.5103 (4)	0.9698 (4)	0.0949 (15)
H10A	0.2989	0.5959	0.9990	0.142*
H10B	0.2407	0.4647	0.9494	0.142*
H10C	0.3749	0.5176	0.8993	0.142*
C11	0.5068 (4)	0.5190 (4)	1.1055 (5)	0.0958 (16)
H11A	0.4737	0.6001	1.1367	0.144*
H11B	0.5620	0.5359	1.0369	0.144*
H11C	0.5570	0.4754	1.1669	0.144*
N1	0.3506 (3)	0.2264 (3)	0.9685 (3)	0.0541 (7)
H1	0.2739 (15)	0.253 (3)	0.954 (3)	0.065*
O1	0.5584 (2)	0.2731 (2)	1.0171 (3)	0.0663 (7)
Cl1	0.26026 (11)	0.19639 (10)	0.71284 (8)	0.0803 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.036 (2)	0.0512 (19)	0.058 (2)	−0.0058 (16)	0.0068 (18)	−0.0057 (16)
C2	0.0393 (19)	0.059 (2)	0.061 (2)	−0.0091 (16)	0.0096 (18)	−0.0019 (18)
C3	0.059 (2)	0.075 (3)	0.077 (3)	−0.008 (2)	0.008 (2)	−0.022 (2)
C4	0.069 (3)	0.063 (3)	0.105 (4)	−0.003 (2)	0.016 (3)	−0.031 (2)
C5	0.067 (3)	0.050 (2)	0.116 (4)	0.0075 (19)	0.001 (3)	0.004 (2)
C6	0.053 (2)	0.058 (2)	0.071 (2)	0.0044 (17)	0.000 (2)	0.002 (2)
C7	0.0353 (18)	0.0538 (18)	0.0463 (17)	−0.0028 (18)	0.0013 (16)	−0.0029 (18)
C8	0.047 (2)	0.0498 (19)	0.063 (2)	−0.0012 (17)	−0.0005 (18)	−0.0107 (17)
C9	0.176 (5)	0.088 (3)	0.073 (3)	−0.005 (3)	0.060 (3)	−0.015 (2)
C10	0.105 (3)	0.066 (2)	0.114 (3)	0.022 (2)	−0.029 (3)	−0.008 (3)
C11	0.071 (3)	0.074 (3)	0.143 (4)	0.004 (2)	−0.022 (3)	−0.034 (3)
N1	0.0377 (15)	0.0533 (16)	0.0713 (17)	0.0076 (14)	−0.0047 (16)	−0.0130 (15)
O1	0.0377 (13)	0.0658 (15)	0.0955 (17)	0.0029 (11)	−0.0005 (14)	−0.0217 (14)
Cl1	0.0859 (7)	0.0839 (7)	0.0712 (6)	−0.0095 (6)	−0.0137 (6)	0.0169 (5)

Geometric parameters (Å, º)

C1—C6	1.372 (5)	C7—C8	1.526 (5)
C1—C2	1.404 (5)	C8—C11	1.491 (5)
C1—N1	1.410 (4)	C8—C9	1.508 (5)
C2—C3	1.374 (5)	C8—C10	1.534 (5)
C2—Cl1	1.732 (3)	C9—H9A	0.9600
C3—C4	1.363 (6)	C9—H9B	0.9600
C3—H3	0.9300	C9—H9C	0.9600
C4—C5	1.365 (6)	C10—H10A	0.9600
C4—H4	0.9300	C10—H10B	0.9600
C5—C6	1.405 (5)	C10—H10C	0.9600
C5—H5	0.9300	C11—H11A	0.9600
C6—H6	0.9300	C11—H11B	0.9600
C7—O1	1.219 (4)	C11—H11C	0.9600
C7—N1	1.348 (4)	N1—H1	0.841 (10)
C6—C1—C2	118.3 (3)	C11—C8—C10	106.2 (3)
C6—C1—N1	121.1 (3)	C9—C8—C10	108.9 (3)
C2—C1—N1	120.6 (3)	C7—C8—C10	109.2 (3)
C3—C2—C1	121.2 (3)	C8—C9—H9A	109.5
C3—C2—Cl1	119.1 (3)	C8—C9—H9B	109.5
C1—C2—Cl1	119.6 (2)	H9A—C9—H9B	109.5
C4—C3—C2	119.4 (4)	C8—C9—H9C	109.5
C4—C3—H3	120.3	H9A—C9—H9C	109.5
C2—C3—H3	120.3	H9B—C9—H9C	109.5
C3—C4—C5	121.0 (4)	C8—C10—H10A	109.5
C3—C4—H4	119.5	C8—C10—H10B	109.5
C5—C4—H4	119.5	H10A—C10—H10B	109.5
C4—C5—C6	119.9 (4)	C8—C10—H10C	109.5
C4—C5—H5	120.1	H10A—C10—H10C	109.5
C6—C5—H5	120.1	H10B—C10—H10C	109.5
C1—C6—C5	120.1 (4)	C8—C11—H11A	109.5
C1—C6—H6	120.0	C8—C11—H11B	109.5
C5—C6—H6	120.0	H11A—C11—H11B	109.5
O1—C7—N1	120.5 (3)	C8—C11—H11C	109.5
O1—C7—C8	123.1 (3)	H11A—C11—H11C	109.5
N1—C7—C8	116.4 (3)	H11B—C11—H11C	109.5
C11—C8—C9	111.7 (4)	C7—N1—C1	125.0 (3)
C11—C8—C7	111.0 (3)	C7—N1—H1	122 (2)
C9—C8—C7	109.7 (3)	C1—N1—H1	112 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1^i	0.84 (1)	2.23 (2)	2.973 (3)	148 (3)

Symmetry code: (i) x−1/2, −y+1/2, −z+2.