2,2,2-Trimethyl-N-(2-methyl­phen­yl)­acetamide

In the structure of the title compound, C₁₂H₁₇NO, the conformation of the N-H bond is syn to the ortho-methyl substituent, in contrast to the anti conformation observed for the corresponding meta-methyl-substituted amide and side-chain-unsubstituted N-(2-methyl­phen­yl)acetamide.

Key indicators

• Single-crystal X-ray study
• T = 299 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.079
• wR factor = 0.222
• Data-to-parameter ratio = 10.0

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT242_ALERT_2_B Check Low       Ueq as Compared to Neighbors for         C4

Alert level C
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       2.86 Ratio
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           26.54
           From the CIF: _reflns_number_total               1375
           Count of symmetry unique reflns         1381
           Completeness (_total/calc)             99.57%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no

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

   0 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
   1 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

---

Computing details

Data collection: CrysAlis (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: ORTEP-3 for Windows (Farrugia, 1997); PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997) PLATON (Spek, 2003) WinGX (Farrugia, 1999).

N-(2-methylphenyl)-2,2,2-trimethylacetamide

Crystal data

C12H17NO	F(000) = 416
Mr = 191.27	Dx = 1.107 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	θ = 2.7–29.6°
a = 10.138 (2) Å	µ = 0.07 mm^−1
b = 10.2597 (19) Å	T = 299 K
c = 11.0305 (19) Å	Prism, colourless
V = 1147.3 (4) Å^3	0.37 × 0.20 × 0.07 mm
Z = 4

Data collection

Xcalibur System, Oxford Diffraction, Ltd. diffractometer	1375 independent reflections
Radiation source: fine-focus sealed tube	1289 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.070
Detector resolution: 8.4012 pixels mm^-1	θmax = 26.5°, θmin = 4.2°
ω scan	h = −12→7
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2006)	k = −12→12
Tmin = 0.965, Tmax = 0.990	l = −13→13
7986 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.080	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.222	H-atom parameters constrained
S = 1.1	w = 1/[σ^2(Fo^2) + (0.1365P)^2 + 0.2494P] where P = (Fo^2 + 2Fc^2)/3
1375 reflections	(Δ/σ)max = 0.001
137 parameters	Δρmax = 0.37 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

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	0.1829 (6)	0.5077 (5)	0.4741 (6)	0.1002 (19)
H1A	0.1236	0.5325	0.4103	0.12*
H1B	0.2507	0.4524	0.4418	0.12*
H1C	0.2222	0.5843	0.5086	0.12*
C2	0.1996 (9)	0.4080 (6)	0.6737 (7)	0.135 (3)
H2A	0.2694	0.3526	0.6453	0.162*
H2B	0.1541	0.3659	0.7393	0.162*
H2C	0.236	0.489	0.7016	0.162*
C3	−0.0062 (5)	0.5178 (5)	0.6082 (7)	0.100 (2)
H3A	−0.0727	0.5144	0.5463	0.12*
H3B	0.0241	0.6059	0.6174	0.12*
H3C	−0.0427	0.4878	0.6835	0.12*
C4	0.1058 (3)	0.4334 (4)	0.5733 (4)	0.0542 (9)
C5	0.0572 (3)	0.3035 (3)	0.5207 (3)	0.0472 (8)
O6	−0.0575 (2)	0.2719 (3)	0.5252 (3)	0.0686 (9)
N7	0.1489 (3)	0.2275 (3)	0.4702 (3)	0.0534 (8)
H7	0.2287	0.2558	0.4694	0.059 (11)*
C8	0.1245 (3)	0.1033 (3)	0.4176 (4)	0.0494 (8)
C9	0.0657 (4)	0.0068 (4)	0.4825 (5)	0.0639 (10)
H9	0.0384	0.0228	0.5616	0.077*
C10	0.0458 (5)	−0.1155 (4)	0.4318 (5)	0.0769 (13)
H10	0.0057	−0.1815	0.4762	0.092*
C11	0.0866 (5)	−0.1369 (5)	0.3149 (6)	0.0830 (15)
H11	0.0741	−0.2183	0.2797	0.1*
C12	0.1453 (4)	−0.0401 (5)	0.2496 (4)	0.0714 (12)
H12	0.1726	−0.057	0.1707	0.086*
C13	0.1649 (3)	0.0822 (4)	0.2979 (3)	0.0527 (9)
C14	0.2293 (5)	0.1887 (5)	0.2260 (4)	0.0755 (12)
H14A	0.2324	0.1643	0.1421	0.091*
H14B	0.3173	0.2025	0.2554	0.091*
H14C	0.1793	0.2677	0.2347	0.091*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.120 (4)	0.069 (3)	0.111 (4)	−0.031 (3)	0.034 (4)	−0.008 (3)
C2	0.213 (8)	0.082 (4)	0.110 (5)	0.014 (5)	−0.089 (5)	−0.021 (3)
C3	0.083 (3)	0.060 (3)	0.158 (6)	−0.006 (2)	0.031 (4)	−0.038 (3)
C4	0.0535 (18)	0.0496 (18)	0.0594 (19)	−0.0026 (15)	0.0009 (15)	−0.0117 (17)
C5	0.0473 (16)	0.0488 (16)	0.0455 (15)	−0.0001 (14)	−0.0017 (15)	−0.0025 (15)
O6	0.0444 (13)	0.0638 (16)	0.098 (2)	−0.0027 (12)	0.0039 (14)	−0.0235 (16)
N7	0.0419 (14)	0.0493 (16)	0.0691 (18)	−0.0026 (12)	0.0052 (14)	−0.0131 (14)
C8	0.0427 (15)	0.0430 (16)	0.063 (2)	0.0035 (13)	−0.0070 (15)	−0.0041 (16)
C9	0.061 (2)	0.052 (2)	0.078 (3)	−0.0026 (18)	0.001 (2)	−0.0016 (19)
C10	0.071 (2)	0.048 (2)	0.111 (4)	−0.0074 (19)	−0.001 (3)	0.005 (2)
C11	0.071 (3)	0.062 (3)	0.116 (4)	0.001 (2)	−0.009 (3)	−0.032 (3)
C12	0.061 (2)	0.075 (3)	0.078 (3)	0.005 (2)	−0.005 (2)	−0.026 (2)
C13	0.0463 (17)	0.056 (2)	0.0562 (19)	0.0069 (15)	−0.0051 (15)	−0.0044 (16)
C14	0.076 (2)	0.087 (3)	0.063 (2)	0.012 (2)	0.009 (2)	0.012 (2)

Geometric parameters (Å, º)

C1—C4	1.546 (7)	N7—H7	0.86
C1—H1A	0.96	C8—C9	1.360 (6)
C1—H1B	0.96	C8—C13	1.400 (5)
C1—H1C	0.96	C9—C10	1.387 (6)
C2—C4	1.483 (7)	C9—H9	0.93
C2—H2A	0.96	C10—C11	1.373 (8)
C2—H2B	0.96	C10—H10	0.93
C2—H2C	0.96	C11—C12	1.363 (7)
C3—C4	1.479 (6)	C11—H11	0.93
C3—H3A	0.96	C12—C13	1.377 (6)
C3—H3B	0.96	C12—H12	0.93
C3—H3C	0.96	C13—C14	1.500 (6)
C4—C5	1.535 (5)	C14—H14A	0.96
C5—O6	1.207 (4)	C14—H14B	0.96
C5—N7	1.335 (4)	C14—H14C	0.96
N7—C8	1.421 (4)
C4—C1—H1A	109.5	C5—N7—C8	124.9 (3)
C4—C1—H1B	109.5	C5—N7—H7	117.5
H1A—C1—H1B	109.5	C8—N7—H7	117.5
C4—C1—H1C	109.5	C9—C8—C13	120.8 (4)
H1A—C1—H1C	109.5	C9—C8—N7	121.0 (4)
H1B—C1—H1C	109.5	C13—C8—N7	118.2 (3)
C4—C2—H2A	109.5	C8—C9—C10	120.7 (5)
C4—C2—H2B	109.5	C8—C9—H9	119.7
H2A—C2—H2B	109.5	C10—C9—H9	119.7
C4—C2—H2C	109.5	C11—C10—C9	118.7 (5)
H2A—C2—H2C	109.5	C11—C10—H10	120.7
H2B—C2—H2C	109.5	C9—C10—H10	120.7
C4—C3—H3A	109.5	C12—C11—C10	120.7 (4)
C4—C3—H3B	109.5	C12—C11—H11	119.6
H3A—C3—H3B	109.5	C10—C11—H11	119.6
C4—C3—H3C	109.5	C11—C12—C13	121.5 (4)
H3A—C3—H3C	109.5	C11—C12—H12	119.2
H3B—C3—H3C	109.5	C13—C12—H12	119.2
C3—C4—C2	113.6 (5)	C12—C13—C8	117.6 (4)
C3—C4—C5	111.1 (3)	C12—C13—C14	121.5 (4)
C2—C4—C5	109.6 (4)	C8—C13—C14	120.9 (4)
C3—C4—C1	106.4 (4)	C13—C14—H14A	109.5
C2—C4—C1	106.9 (5)	C13—C14—H14B	109.5
C5—C4—C1	108.8 (3)	H14A—C14—H14B	109.5
O6—C5—N7	122.1 (3)	C13—C14—H14C	109.5
O6—C5—C4	121.7 (3)	H14A—C14—H14C	109.5
N7—C5—C4	116.2 (3)	H14B—C14—H14C	109.5
C3—C4—C5—O6	−9.5 (6)	N7—C8—C9—C10	−178.0 (4)
C2—C4—C5—O6	117.0 (5)	C8—C9—C10—C11	−0.1 (7)
C1—C4—C5—O6	−126.4 (5)	C9—C10—C11—C12	−0.1 (7)
C3—C4—C5—N7	170.7 (4)	C10—C11—C12—C13	−0.4 (7)
C2—C4—C5—N7	−62.9 (6)	C11—C12—C13—C8	1.1 (6)
C1—C4—C5—N7	53.8 (5)	C11—C12—C13—C14	−179.9 (4)
O6—C5—N7—C8	−0.5 (6)	C9—C8—C13—C12	−1.3 (5)
C4—C5—N7—C8	179.4 (4)	N7—C8—C13—C12	177.6 (3)
C5—N7—C8—C9	−55.9 (5)	C9—C8—C13—C14	179.7 (4)
C5—N7—C8—C13	125.3 (4)	N7—C8—C13—C14	−1.4 (5)
C13—C8—C9—C10	0.8 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N7—H7···O6^i	0.86	2.19	2.977 (4)	153

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