4-[4-(Dimethyl­amino)benzyl­idene]-2,6-dimethyl­cyclo­hexa-2,5-dienone

Nathalie Hampel; Dorothea Richter; Armin R Ofial; Herbert Mayr; Peter Mayer

doi:10.1107/S1600536809030748

. 2009 Aug 8;65(Pt 9):o2102. doi: 10.1107/S1600536809030748

4-[4-(Dimethylamino)benzylidene]-2,6-dimethylcyclohexa-2,5-dienone

Nathalie Hampel ^a, Dorothea Richter ^a, Armin R Ofial ^a, Herbert Mayr ^a, Peter Mayer ^a,^*

PMCID: PMC2969876 PMID: 21577517

Abstract

The title compound, C₁₇H₁₉NO, crystallized with two molecules per asymmetric unit. C—H⋯O hydrogen bonds lead to infinite chains along [100]. According to graph-set theory, the descriptor C ₁ ¹(13)C ₁ ¹(13) can be assigned.

Related literature

For a related structure, see: Kawai et al. (2004 ▶). For background to graph set analysis, see: Bernstein et al. (1995 ▶); Etter et al. (1990 ▶). For the preparation, see: Richter et al. (2009 ▶).

Experimental

Crystal data

C₁₇H₁₉NO
M _r = 253.34
Monoclinic,
a = 14.5357 (3) Å
b = 7.2759 (2) Å
c = 27.5473 (5) Å
β = 104.6463 (14)°
V = 2818.74 (11) Å³
Z = 8
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 200 K
0.24 × 0.20 × 0.19 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: none
18635 measured reflections
5725 independent reflections
3685 reflections with I > 2σ(I)
R _int = 0.051

Refinement

R[F ² > 2σ(F ²)] = 0.049
wR(F ²) = 0.131
S = 1.02
5725 reflections
351 parameters
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Data collection: COLLECT (Hooft, 2004 ▶); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO (Otwinowski & Minor, 1997 ▶) and SCALEPACK; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809030748/fl2253sup1.cif

e-65-o2102-sup1.cif^{(26.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809030748/fl2253Isup2.hkl

e-65-o2102-Isup2.hkl^{(280.3KB, hkl)}

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
C17—H17B⋯O1ⁱ	0.98	2.51	3.456 (2)	163
C34—H34B⋯O2ⁱ	0.98	2.36	3.328 (2)	169

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Professor Peter Klüfers for generous allocation of diffractometer time.

supplementary crystallographic information

Comment

The asymmetric unit of (I) contains two complete molecules of the title compound. Figure 1 shows one of the two independent molecules.

A major difference between the two symmetrically independent molecules is found in the angle formed by the planes of the two C₆-rings within a molecule. This angle is found to be 35.19 (7)° between the planes in one molecule but only 20.00 (7)° between the planes in the other molecule (Fig. 2). With a bulky naphthyl substituent at the C atom linking the two rings, an angle of 43.16 (6)° is observed [Kawai et al. (2004)].

The molecular packing, which is shown in Figure 3, is dominated by two C—H···O hydrogen bonds leading to infinite chains along [100]. Each of the chains is built up by 13 atoms and contains one donor atom and one acceptor atom. According to graph set theory [Bernstein et al. (1995), Etter et al. (1990)] the descriptor C₁¹(13)C₁¹(13) can be assigned. The strands are cross-linked by very weak C—H···C contacts with H···C distances of at least 2.79 Å (Table 1).

Experimental

The title compound was prepared under an atmosphere of dry N₂ from (4-hydroxy-3,5-dimethylphenyl)[4-(dimethylamino)phenyl]methanol [Richter et al. (2009)] (200 mg, 0.737 mmol) that was dissolved in dry CH₂Cl₂ (60 ml) and cooled to 0 °C. Then etheral HBF₄-solution (0.110 ml, 0.811 mmol) was added at 0 °C. After 5 min, NEt₃ (0.133 ml, 0.958 mmol) was added. The cooling bath was removed and stirring was continued for 3 h before the mixture was washed with water (3 times). The organic layer was dried (MgSO₄) and the solvent was removed under reduced pressure. Crystals were obtained by slow cooling of a warm solution of the title compound in acetonitrile. Yield: 149 mg (80%), mp 127–128 °C.