2,2,2-Trichloro-N-(2,5-dimethyl­phen­yl)acetamide

The N—H bond in the title compound, C₁₀H₁₀Cl₃NO, is syn to the 2-methyl and anti to the 5-methyl substituent of the aromatic ring. Adjacent mol­ecules are linked into chains through N—H...O hydrogen bonding. Two Cl atoms are each disordered equally over two sites.

Key indicators

• Single-crystal X-ray study
• T = 299 K
• Mean [sigma](C-C) = 0.014 Å
• Disorder in main residue
• R factor = 0.089
• wR factor = 0.309
• Data-to-parameter ratio = 15.0

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT241_ALERT_2_A Check High      Ueq as Compared to Neighbors for        Cl2

Author Response: Cl1, Cl2, Cl3 of the CCl~3~ group are disordered and Cl1 and Cl3 have been refined using a split model. For Cl2 no reliable disorder model could be produced. Because of this disorder displacement parameters are unusually high.

Alert level B
PLAT026_ALERT_3_B Ratio Observed / Unique Reflections too Low ....         30 Perc.
PLAT230_ALERT_2_B Hirshfeld Test Diff for    Cl2    -   Cl3B    ..       8.07 su
PLAT242_ALERT_2_B Check Low       Ueq as Compared to Neighbors for         C4
PLAT340_ALERT_3_B Low Bond Precision on C-C Bonds (x 1000) Ang ...         14
PLAT431_ALERT_2_B Short Inter HL..A Contact  Cl1A   ..  Cl2     ..       3.07 Ang.

Alert level C
RFACR01_ALERT_3_C  The value of the weighted R factor is > 0.25
            Weighted R factor given   0.308
STRVA01_ALERT_4_C           Flack parameter is too small
           From the CIF: _refine_ls_abs_structure_Flack   -0.400
           From the CIF: _refine_ls_abs_structure_Flack_su    0.400
PLAT032_ALERT_4_C Std. Uncertainty in Flack Parameter too High ...       0.40
PLAT033_ALERT_2_C Flack Parameter Value Deviates from zero .......      -0.40
PLAT084_ALERT_2_C High R2 Value ..................................       0.31
PLAT230_ALERT_2_C Hirshfeld Test Diff for    Cl1A   -   Cl1B    ..       6.51 su
PLAT230_ALERT_2_C Hirshfeld Test Diff for    Cl2    -   C4      ..       6.91 su
PLAT230_ALERT_2_C Hirshfeld Test Diff for    Cl3A   -   Cl3B    ..       5.93 su
PLAT230_ALERT_2_C Hirshfeld Test Diff for    N7     -   C8      ..       5.81 su
PLAT301_ALERT_3_C Main Residue  Disorder .........................      12.00 Perc.
PLAT779_ALERT_2_C Suspect or Irrelevant (Bond) Angle in CIF ......      43.00 Deg.
              CL3B -C4   -CL3A    1.555   1.555   1.555
PLAT779_ALERT_2_C Suspect or Irrelevant (Bond) Angle in CIF ......      32.10 Deg.
              CL1B -C4   -CL1A    1.555   1.555   1.555

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               2314
           Count of symmetry unique reflns         1427
           Completeness (_total/calc)            162.16%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       887
           Fraction of Friedel pairs measured     0.622
           Are heavy atom types Z>Si present        yes
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......         37

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

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

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S1. Comment

In the present work, the structure of 2,2,2-trichloro-N- (2,5-dimethylphenyl)acetamide (25DMPTCA) has been determined to study the effect of substituents on the structures of N-aromatic amides (Gowda, Foro et al., 2007; Gowda, Kožíšek et al., 2007). The conformation of the N—H bond in 25DMPTCA is syn to the 2-methyl and anti to the 5-methyl substituents in the aromatic ring (Fig. 1), similar to the syn conformation observed with respect to the 2-methyl substituent in 2,2,2-trichloro-N-(2-methylphenyl)acetamide (2MPTCA) (Gowda, Kožíšek et al., 2007). The bond parameters in 25DMPTCA are similar to those in 2MPTCA, 2,2,2-trichloro-N-(2,6-dimethylphenyl)- acetamide and other acetanilides (Gowda, Foro et al., 2007; Gowda, Kožíšek et al., 2007). The intermolecular N—H···O hydrogen bonds link the molecules into chains (Table 1 and Fig.2). The Cl atoms of CCl₃ group are disordered and Cl1 and Cl3 were refined using a split model with site-occupation factors 0.5:0.5. No reliable disorder model could be produced for Cl2.

Related literature

For related literature, see: Gowda, Foro & Fuess (2007); Gowda, Kožíšek et al. (2007); Shilpa & Gowda (2007).

S2. Experimental

The title compound was prepared according to the literature method (Shilpa and 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 and Gowda, 2007). 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 H atoms were positioned with idealized geometry using a riding model with C—H = 0.93–0.96 Å, N—H = 0.86 Å. All H atoms were refined with isotropic displacement parameters (set to 1.2 times of the U_eq of the parent atom).

The Cl atoms of CCl₃ group are disordered and Cl1 and Cl3 were refined using a split model with site-occupation factors 0.5:0.5. No reliable disorder model could be produced for Cl2. The C—Cl distances were restrained to 1.77 (2) Å and the distances in the disordered groups were restrained to be equal.

The compound is a weak anamalous scatterer with minor intensity at high θ value. The low fraction of unique data is above the 2σ level (30°).

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2004); cell refinement: CrysAlis RED (Oxford Diffraction, 2007); data reduction: CrysAlis RED (Oxford Diffraction, 2007); 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 (Sheldrick, 2008).

Figures

	Fig. 1. Molecular structure of the title compound, showing the atom labeling scheme. The displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. Molecular packing of the title compound with hydrogen bonding shown as dashed lines.

2,2,2-Trichloro-N-(2,5-dimethylphenyl)acetamide

Crystal data

C10H10Cl3NO	F(000) = 544
Mr = 266.54	Dx = 1.514 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 1061 reflections
a = 4.9173 (9) Å	θ = 2.6–28.1°
b = 11.290 (1) Å	µ = 0.76 mm^−1
c = 21.070 (2) Å	T = 299 K
V = 1169.7 (3) Å^3	Prism, colourless
Z = 4	0.16 × 0.12 × 0.06 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with Sapphire CCD detector	2314 independent reflections
Radiation source: Enhance (Mo) X-ray Source	703 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.071
Rotation method data acquisition using ω and phi scans.	θmax = 26.4°, θmin = 3.4°
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007)	h = −6→6
Tmin = 0.889, Tmax = 0.956	k = −14→13
6121 measured reflections	l = −26→23

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)] = 0.088	H-atom parameters constrained
wR(F^2) = 0.309	w = 1/[σ^2(Fo^2) + (0.1675P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.86	(Δ/σ)max = 0.003
2314 reflections	Δρmax = 0.27 e Å^−3
154 parameters	Δρmin = −0.76 e Å^−3
37 restraints	Absolute structure: Flack (1983), 887 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.4 (4)

Special details

Experimental. 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	Occ. (<1)
Cl1A	0.4909 (19)	0.3895 (7)	0.5055 (3)	0.096 (2)	0.50
Cl1B	0.301 (3)	0.3888 (10)	0.5125 (4)	0.139 (4)	0.50
Cl2	0.0276 (14)	0.5253 (7)	0.5201 (3)	0.218 (3)
Cl3A	0.459 (2)	0.6280 (6)	0.4526 (3)	0.102 (2)	0.50
Cl3B	0.226 (2)	0.6324 (7)	0.4737 (5)	0.141 (3)	0.50
O6	−0.0518 (17)	0.4448 (7)	0.3920 (4)	0.092 (3)
N7	0.3670 (16)	0.4054 (7)	0.3571 (4)	0.069 (2)
H7N	0.5356	0.4163	0.3662	0.083*
C4	0.311 (2)	0.4931 (7)	0.4592 (4)	0.082 (3)
C5	0.180 (3)	0.4444 (9)	0.4003 (6)	0.075 (3)
C8	0.308 (2)	0.3488 (8)	0.2991 (4)	0.055 (3)
C9	0.4334 (19)	0.2416 (9)	0.2866 (5)	0.062 (3)
C10	0.358 (2)	0.1877 (10)	0.2267 (5)	0.079 (3)
H10	0.4336	0.1151	0.2154	0.095*
C11	0.178 (2)	0.2420 (10)	0.1863 (4)	0.067 (3)
H11	0.1371	0.2054	0.1480	0.080*
C12	0.055 (2)	0.3486 (10)	0.2002 (5)	0.069 (3)
C13	0.125 (2)	0.4011 (9)	0.2572 (4)	0.062 (3)
H13	0.0466	0.4735	0.2679	0.074*
C14	0.624 (2)	0.1827 (8)	0.3309 (5)	0.075 (3)
H14A	0.5312	0.1655	0.3700	0.090*
H14B	0.7750	0.2341	0.3392	0.090*
H14C	0.6878	0.1103	0.3123	0.090*
C15	−0.138 (2)	0.4037 (11)	0.1548 (5)	0.091 (3)
H15A	−0.2838	0.3497	0.1462	0.109*
H15B	−0.0441	0.4218	0.1160	0.109*
H15C	−0.2094	0.4753	0.1727	0.109*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1A	0.116 (6)	0.109 (5)	0.063 (3)	0.023 (5)	0.000 (4)	−0.003 (3)
Cl1B	0.172 (8)	0.151 (7)	0.093 (5)	−0.036 (7)	0.005 (6)	0.037 (5)
Cl2	0.213 (6)	0.278 (7)	0.163 (4)	0.011 (6)	0.007 (4)	−0.053 (4)
Cl3A	0.135 (6)	0.086 (4)	0.086 (4)	−0.038 (4)	0.016 (4)	−0.025 (3)
Cl3B	0.151 (7)	0.117 (6)	0.154 (6)	0.018 (6)	−0.027 (6)	−0.049 (5)
O6	0.052 (4)	0.127 (7)	0.099 (5)	0.011 (5)	−0.007 (4)	−0.040 (5)
N7	0.049 (5)	0.068 (5)	0.092 (6)	−0.004 (5)	−0.014 (5)	0.016 (5)
C4	0.091 (8)	0.070 (7)	0.084 (7)	0.002 (7)	−0.025 (7)	−0.019 (6)
C5	0.056 (7)	0.081 (8)	0.088 (7)	0.011 (7)	−0.018 (7)	−0.019 (6)
C8	0.055 (6)	0.061 (6)	0.048 (5)	−0.009 (6)	0.004 (6)	−0.005 (5)
C9	0.045 (5)	0.056 (6)	0.086 (7)	0.011 (6)	0.004 (6)	0.018 (6)
C10	0.079 (8)	0.064 (7)	0.095 (8)	−0.004 (7)	0.000 (7)	−0.012 (6)
C11	0.077 (8)	0.064 (7)	0.061 (6)	−0.004 (7)	0.005 (6)	0.005 (5)
C12	0.063 (7)	0.078 (8)	0.066 (6)	−0.016 (7)	−0.003 (6)	0.022 (6)
C13	0.062 (6)	0.062 (5)	0.062 (6)	0.006 (6)	−0.005 (6)	0.010 (5)
C14	0.073 (7)	0.050 (6)	0.102 (7)	0.001 (7)	−0.004 (7)	0.000 (6)
C15	0.080 (8)	0.119 (9)	0.074 (6)	−0.001 (9)	−0.017 (7)	0.019 (7)

Geometric parameters (Å, º)

Cl1A—C4	1.761 (11)	C10—C11	1.373 (14)
Cl1B—C4	1.628 (11)	C10—H10	0.9300
Cl2—C4	1.931 (10)	C11—C12	1.378 (13)
Cl3A—C4	1.693 (10)	C11—H11	0.9300
Cl3B—C4	1.656 (10)	C12—C13	1.382 (14)
O6—C5	1.151 (11)	C12—C15	1.484 (14)
N7—C5	1.367 (13)	C13—H13	0.9300
N7—C8	1.411 (11)	C14—H14A	0.9600
N7—H7N	0.8600	C14—H14B	0.9600
C4—C5	1.503 (13)	C14—H14C	0.9600
C8—C9	1.383 (12)	C15—H15A	0.9600
C8—C13	1.393 (13)	C15—H15B	0.9600
C9—C10	1.449 (14)	C15—H15C	0.9600
C9—C14	1.480 (12)
C5—N7—C8	125.7 (8)	C10—C9—C14	121.5 (9)
C5—N7—H7N	117.1	C11—C10—C9	121.1 (10)
C8—N7—H7N	117.1	C11—C10—H10	119.5
C5—C4—Cl1B	106.9 (8)	C9—C10—H10	119.5
C5—C4—Cl3B	113.0 (8)	C10—C11—C12	122.8 (10)
Cl1B—C4—Cl3B	123.5 (8)	C10—C11—H11	118.6
C5—C4—Cl3A	116.5 (7)	C12—C11—H11	118.6
Cl1B—C4—Cl3A	136.1 (7)	C11—C12—C13	116.8 (9)
Cl3B—C4—Cl3A	43.0 (5)	C11—C12—C15	120.6 (10)
C5—C4—Cl1A	115.4 (7)	C13—C12—C15	122.6 (11)
Cl1B—C4—Cl1A	32.1 (4)	C12—C13—C8	121.9 (9)
Cl3B—C4—Cl1A	131.0 (7)	C12—C13—H13	119.1
Cl3A—C4—Cl1A	115.4 (7)	C8—C13—H13	119.1
C5—C4—Cl2	107.8 (8)	C9—C14—H14A	109.5
Cl1B—C4—Cl2	69.8 (7)	C9—C14—H14B	109.5
Cl3B—C4—Cl2	61.1 (6)	H14A—C14—H14B	109.5
Cl3A—C4—Cl2	101.2 (5)	C9—C14—H14C	109.5
Cl1A—C4—Cl2	96.8 (6)	H14A—C14—H14C	109.5
O6—C5—N7	124.5 (10)	H14B—C14—H14C	109.5
O6—C5—C4	123.3 (12)	C12—C15—H15A	109.5
N7—C5—C4	112.1 (10)	C12—C15—H15B	109.5
C9—C8—C13	122.6 (9)	H15A—C15—H15B	109.5
C9—C8—N7	118.0 (9)	C12—C15—H15C	109.5
C13—C8—N7	119.4 (9)	H15A—C15—H15C	109.5
C8—C9—C10	114.8 (9)	H15B—C15—H15C	109.5
C8—C9—C14	123.7 (9)
C8—N7—C5—O6	−7.0 (17)	C13—C8—C9—C10	−0.2 (13)
C8—N7—C5—C4	176.0 (8)	N7—C8—C9—C10	178.7 (9)
Cl1B—C4—C5—O6	84.0 (14)	C13—C8—C9—C14	−178.4 (9)
Cl3B—C4—C5—O6	−55.0 (16)	N7—C8—C9—C14	0.6 (13)
Cl3A—C4—C5—O6	−102.5 (14)	C8—C9—C10—C11	0.6 (14)
Cl1A—C4—C5—O6	117.4 (13)	C14—C9—C10—C11	178.8 (9)
Cl2—C4—C5—O6	10.4 (14)	C9—C10—C11—C12	−1.1 (17)
Cl1B—C4—C5—N7	−99.0 (10)	C10—C11—C12—C13	1.0 (15)
Cl3B—C4—C5—N7	121.9 (10)	C10—C11—C12—C15	179.7 (10)
Cl3A—C4—C5—N7	74.5 (11)	C11—C12—C13—C8	−0.6 (14)
Cl1A—C4—C5—N7	−65.6 (11)	C15—C12—C13—C8	−179.3 (9)
Cl2—C4—C5—N7	−172.6 (7)	C9—C8—C13—C12	0.3 (14)
C5—N7—C8—C9	−127.3 (10)	N7—C8—C13—C12	−178.7 (9)
C5—N7—C8—C13	51.7 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N7—H7N···O6^i	0.86	2.12	2.984 (11)	178

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