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Acta Crystallogr Sect E Struct Rep Online. 2010 July 1; 66(Pt 7): o1798–o1799.
Published online 2010 June 26. doi:  10.1107/S1600536810022142
PMCID: PMC3007056

2′,3,4,4′-Tetra­meth­oxy­chalcone

Abstract

In the title compound [systematic name: 1-(2,4-dimethoxyphenyl)-3-(3,4-dimethoxyphenyl)prop-2-en-1-one], C19H20O5, the dihedral angle between the benzene rings is 26.88 (5)°. One of the meth­oxy groups is twisted slightly away from the plane [C—O—C—C torsion angle = −12.8 (3)°] while the others are almost co-planer [C—O—C—C torsion angles = −3.2 (3), 2.6 (3) and −3.6 (3)°]. The crystal packing is stabilized by inter­molecular C—H(...)O inter­actions. A weak intra­molecular C—H(...)O inter­action occurs.

Related literature

For properties and uses of chalcones, see: Marais et al. (2005 [triangle]); Fichou et al. (1988 [triangle]); Uchida et al. (1998 [triangle]). For the biological activity of flavenoids, see: Pietta et al. (2003 [triangle]). For related structures, see: Patil et al. (2006a [triangle],b [triangle],c [triangle]); Teh et al. (2006a [triangle],b [triangle],c [triangle]); Rosli et al. (2006 [triangle]). For the synthesis of the title compound, see: Kraus et al. (2008 [triangle]). For bond-length data, see: Allen et al. (1987 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-o1798-scheme1.jpg

Experimental

Crystal data

  • C19H20O5
  • M r = 328.35
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-o1798-efi1.jpg
  • a = 12.5839 (7) Å
  • b = 11.7204 (7) Å
  • c = 12.1339 (6) Å
  • β = 109.489 (2)°
  • V = 1687.07 (16) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.09 mm−1
  • T = 100 K
  • 0.49 × 0.22 × 0.07 mm

Data collection

  • Bruker APEXII diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2008 [triangle]) T min = 0.976, T max = 0.994
  • 32681 measured reflections
  • 4205 independent reflections
  • 2539 reflections with I > 2σ(I)
  • R int = 0.039

Refinement

  • R[F 2 > 2σ(F 2)] = 0.044
  • wR(F 2) = 0.188
  • S = 1.12
  • 4205 reflections
  • 225 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.21 e Å−3
  • Δρmin = −0.20 e Å−3

Data collection: APEX2 (Bruker, 2008 [triangle]); cell refinement: SAINT-Plus (Bruker, 2008 [triangle]); data reduction: SAINT-Plus and XPREP (Bruker, 2008 [triangle]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: DIAMOND (Brandenberg & Putz, 2005 [triangle]); software used to prepare material for publication: WingGX (Farrugia, 1999 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810022142/hg2688sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810022142/hg2688Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The University of the Free State is gratefully acknowledged for financial support, Alice Brink for the data collection and Marietjie Schutte for her valueable input.

supplementary crystallographic information

Comment

Flavonoids are a prominent class of secondary plant metabolites known for their wide range of biological active compounds that exibit antibacterial, antifugal, antitumor and anti-inflammatory properties (Pietta et al., 2003). Chalcones are an important subclass of these compounds and are often utilized as intermediates in the synthesis of a variety of cyclic flavonoids (Marais et al., 2005). Furthermore, many chalcone derivatives are known to have excellent non-linear optical (NLO) properties (Fichou et al., 1988; Uchida et al., 1998; Patil et al., 2006a,b). We report here a new chalcone which we have successfully synthesized (the title compound, (I)). Bond distances in (I) have normal values (Allen et al., 1987) and bond angles and distances are comparable to those in related structures (Teh et al., 2006a,b,c; Patil et al., 2006a,b,c; Rosli et al. 2006). The least squares plane through the enone group (C7, C8, C9 and O3) exhibit dihedral angles of 29.2 (1)° and 4.5 (1)° with the C1—C6 and C10—C15 benzene rings, respectively. The dihedral angle between the two benzene rings is 26.88 (5)°. The methoxy group attached at C1 is slightly twisted away from the C1—C6 benzene ring plane, with a C16—O1—C1—C2 torsion angle of -12.8 (3)°. The methoxy groups at C3, C12 and C13 are almost co-planar with the C1—C6 and C10—C15 benzene rings with C17—O2—C3—C2, C18—O4—C12—C11 and C19—O5—C13—C14 torsion angels of -3.2 (3)°, 2.6 (3)° and -3.6 (3)°, respectively. An intramolecular C8—H8···O1 hydrogen bond is observed in the molecular structure of (I), while the molecules form chains through intermolecular C18—H18B···O3i hydrogen bonds (Table 1).

Experimental

The title compoud was synthesized according to the procedure by Kraus et al. (2008) Freshly ground KOH (1.55 g; 27.80 mmol; 5 eq.) was added to a cold (ice bath) stirring solution of 2',4'-dimethoxyacetophenone (1.00 g; 5.56 mmol) and 3,4-dimethoxybenzaldehyde (1.13 g; 7.12 mmol; 1.2 eq.) in EtOH (40 ml). The reaction mixture was allowed to heat to room temperature and stirred to completion (TLC). Ice was added to the reaction mixture prior to acidification with concentrated HCl (litmus). Extraction was performed with EtOAc (3 x 100 ml) and the organic fractions combined. The organic phase was neutralized with a saturated solution of NaHCO3 (litmus), washed with water, dried (Na2SO4) and evaporated in vacuo at ca 40 °C. Crystallization from EtOH afforded the desired chalcone (1.55 g; 84.7%) as yellow needles. Rf 0.16 (H:A; 8:2); Mp 88.3 °C; 1H NMR (600 MHz, CDCl3) δ 7.69 (1H, d, J = 8.61 Hz, H-6'), 7.58 (1H, d, J = 15.71 Hz, H-β), 7.33 (1H, d, J = 15.71 Hz, H-α), 7.14 (1H, dd, J = 1.92, 8.32 Hz, H-5), 7.08 (1H, d, J = 1.92 Hz, H-2), 6.84 (1H, d, J = 8.32 Hz, H-6), 6.52 (1H, dd, J = 2.25, 8.61 Hz, H-5'), 6.46 (1H, d, J = 2.25 Hz, H– 3'), 3.88 (3H, s, –OCH3), 3.87 (3H, s, –OCH3), 3.85 (3H, s, –OCH3), 3.82 (3H, s, –OCH3); 13C NMR (151 MHz, CDCl3) δ 190.58, 163.96, 160.21, 150.95, 149.11, 142.34 (C-β), 132.63 (C-6'), 128.39, 125.28 (C-α), 122.60 (C-5), 122.36, 111.13 (C-6), 110.24 (C-2), 105.14 (C-5'), 98.66 (C-3'), 55.94 (–OCH3), 55.86 (–OCH3), 55.71 (–OCH3), 55.50 (–OCH3).

Refinement

The aromatic H atoms were placed in geometrically idealized positions and constrained to ride on its parent atoms with Uiso (H) = 1.2Ueq(C) and at a distance of 0.93 Å. The hydrogen atoms of the methine (H8 and H9) group were determined from a difference Fourier map and their positional parameters freely refined (C8—H8 = 0.96 (2)Å and C9—H9 = 1.01 (2) Å). The methyl H atoms were placed in geometrically idealized positions and constrained to ride on its parent atoms with Uiso(H) = 1.5Ueq(C) and at a distance of 0.96 Å.

Figures

Fig. 1.
Representation of the title compound, showing the numbering scheme and displacement ellipsoids (50% probability).

Crystal data

C19H20O5F(000) = 696
Mr = 328.35Dx = 1.293 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 7154 reflections
a = 12.5839 (7) Åθ = 2.4–23.6°
b = 11.7204 (7) ŵ = 0.09 mm1
c = 12.1339 (6) ÅT = 100 K
β = 109.489 (2)°Plate, colourless
V = 1687.07 (16) Å30.49 × 0.22 × 0.07 mm
Z = 4

Data collection

Bruker APEXII diffractometer2539 reflections with I > 2σ(I)
graphiteRint = 0.039
phi and ω scansθmax = 28.4°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2008)h = −16→16
Tmin = 0.976, Tmax = 0.994k = −15→15
32681 measured reflectionsl = −11→16
4205 independent reflections

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.044Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.188H atoms treated by a mixture of independent and constrained refinement
S = 1.12w = 1/[σ2(Fo2) + (0.0998P)2 + 0.0628P] where P = (Fo2 + 2Fc2)/3
4205 reflections(Δ/σ)max = 0.001
225 parametersΔρmax = 0.21 e Å3
0 restraintsΔρmin = −0.20 e Å3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 (Å2)

xyzUiso*/Ueq
C10.57536 (15)0.12721 (14)0.10767 (13)0.0572 (4)
C20.66866 (16)0.07753 (15)0.09002 (15)0.0635 (5)
H20.71380.0270.14490.076*
C30.69406 (17)0.10359 (16)−0.00938 (16)0.0665 (5)
C40.62632 (18)0.17787 (18)−0.09154 (16)0.0724 (5)
H40.64220.1941−0.15940.087*
C50.53595 (17)0.22720 (17)−0.07222 (14)0.0654 (5)
H50.49180.2781−0.12740.079*
C60.50707 (15)0.20426 (14)0.02731 (13)0.0555 (4)
C70.40909 (15)0.26733 (15)0.04011 (13)0.0582 (4)
C80.33980 (16)0.21568 (16)0.10368 (15)0.0603 (5)
C90.25176 (15)0.26831 (16)0.11757 (14)0.0596 (5)
C100.18227 (14)0.22631 (15)0.18413 (14)0.0570 (4)
C110.20392 (14)0.12066 (15)0.24240 (14)0.0571 (4)
H110.26270.07560.23670.068*
C120.14066 (14)0.08267 (15)0.30728 (14)0.0574 (4)
C130.05259 (14)0.15026 (17)0.31711 (15)0.0614 (5)
C140.02979 (16)0.25345 (18)0.26000 (16)0.0692 (5)
H14−0.02920.29820.26560.083*
C150.09404 (16)0.29117 (17)0.19425 (16)0.0676 (5)
H150.07770.36120.15630.081*
C160.60374 (18)0.01862 (18)0.28377 (17)0.0782 (6)
H16A0.57620.01640.34860.117*
H16B0.68360.03180.3120.117*
H16C0.5882−0.05290.24290.117*
C170.86153 (19)−0.0100 (2)0.0519 (2)0.0954 (7)
H17A0.9212−0.03350.02410.143*
H17B0.8224−0.07610.06530.143*
H17C0.89270.03150.12370.143*
C180.24973 (17)−0.08614 (17)0.36379 (18)0.0710 (5)
H18A0.2528−0.15440.40850.107*
H18B0.3184−0.04390.39670.107*
H18C0.2405−0.10610.28440.107*
C19−0.09188 (18)0.1716 (2)0.4026 (2)0.0927 (7)
H19A−0.12520.13020.4510.139*
H19B−0.14840.18790.32860.139*
H19C−0.06070.24180.44030.139*
O10.54938 (13)0.10796 (12)0.20672 (10)0.0780 (4)
O20.78452 (13)0.06147 (14)−0.03354 (13)0.0874 (5)
O30.38578 (12)0.36122 (11)−0.00560 (11)0.0767 (4)
O40.15725 (11)−0.01826 (11)0.36644 (12)0.0717 (4)
O5−0.00515 (11)0.10484 (13)0.38441 (12)0.0785 (4)
H80.3591 (17)0.1401 (19)0.1332 (17)0.075 (6)*
H90.2294 (16)0.3460 (17)0.0808 (16)0.071 (5)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
C10.0751 (11)0.0504 (9)0.0446 (8)−0.0050 (8)0.0182 (8)−0.0034 (7)
C20.0785 (12)0.0527 (10)0.0560 (9)−0.0032 (9)0.0180 (9)−0.0043 (8)
C30.0762 (12)0.0620 (12)0.0645 (10)−0.0128 (9)0.0279 (9)−0.0147 (9)
C40.0920 (14)0.0757 (13)0.0567 (10)−0.0123 (11)0.0342 (10)−0.0027 (9)
C50.0802 (13)0.0633 (11)0.0498 (9)−0.0111 (9)0.0176 (8)0.0044 (8)
C60.0685 (10)0.0508 (9)0.0431 (8)−0.0099 (8)0.0132 (7)−0.0021 (7)
C70.0725 (11)0.0511 (10)0.0446 (8)−0.0058 (8)0.0110 (7)0.0012 (7)
C80.0714 (12)0.0497 (10)0.0566 (9)−0.0034 (9)0.0171 (8)0.0030 (8)
C90.0670 (11)0.0513 (10)0.0526 (9)−0.0035 (9)0.0094 (8)−0.0001 (8)
C100.0586 (10)0.0538 (10)0.0518 (8)−0.0006 (8)0.0092 (7)−0.0036 (7)
C110.0563 (9)0.0538 (10)0.0592 (9)0.0007 (8)0.0167 (8)−0.0018 (8)
C120.0565 (10)0.0527 (10)0.0593 (9)−0.0041 (8)0.0143 (8)−0.0027 (8)
C130.0541 (9)0.0673 (12)0.0610 (9)−0.0043 (8)0.0168 (8)−0.0096 (9)
C140.0586 (11)0.0715 (13)0.0739 (11)0.0105 (9)0.0172 (9)−0.0051 (10)
C150.0668 (11)0.0596 (11)0.0677 (11)0.0070 (9)0.0110 (9)0.0027 (9)
C160.0932 (14)0.0743 (13)0.0629 (10)0.0076 (11)0.0204 (10)0.0213 (10)
C170.0753 (14)0.1100 (19)0.0954 (16)0.0027 (13)0.0213 (12)−0.0291 (14)
C180.0812 (13)0.0533 (11)0.0818 (12)0.0052 (9)0.0316 (10)0.0076 (9)
C190.0673 (12)0.125 (2)0.0908 (14)0.0056 (13)0.0336 (11)−0.0140 (14)
O10.1039 (10)0.0834 (10)0.0517 (7)0.0266 (8)0.0326 (7)0.0199 (6)
O20.0914 (10)0.0909 (11)0.0904 (10)−0.0003 (8)0.0444 (8)−0.0111 (8)
O30.0972 (10)0.0607 (8)0.0724 (8)0.0086 (7)0.0284 (7)0.0193 (7)
O40.0769 (9)0.0598 (8)0.0869 (9)0.0028 (6)0.0385 (7)0.0107 (6)
O50.0707 (8)0.0858 (10)0.0877 (9)−0.0012 (7)0.0378 (7)−0.0051 (7)

Geometric parameters (Å, °)

C1—O11.3654 (19)C12—C131.399 (2)
C1—C21.390 (3)C13—O51.369 (2)
C1—C61.395 (2)C13—C141.376 (3)
C2—C31.381 (3)C14—C151.384 (3)
C2—H20.93C14—H140.93
C3—O21.359 (2)C15—H150.93
C3—C41.382 (3)C16—O11.418 (2)
C4—C51.364 (3)C16—H16A0.96
C4—H40.93C16—H16B0.96
C5—C61.398 (2)C16—H16C0.96
C5—H50.93C17—O21.430 (3)
C6—C71.489 (3)C17—H17A0.96
C7—O31.223 (2)C17—H17B0.96
C7—C81.473 (3)C17—H17C0.96
C8—C91.327 (3)C18—O41.419 (2)
C8—H80.96 (2)C18—H18A0.96
C9—C101.460 (3)C18—H18B0.96
C9—H91.01 (2)C18—H18C0.96
C10—C151.384 (3)C19—O51.418 (3)
C10—C111.407 (2)C19—H19A0.96
C11—C121.367 (2)C19—H19B0.96
C11—H110.93C19—H19C0.96
C12—O41.363 (2)
O1—C1—C2121.95 (15)O5—C13—C12115.08 (17)
O1—C1—C6116.73 (16)C14—C13—C12119.51 (17)
C2—C1—C6121.24 (15)C13—C14—C15120.49 (17)
C3—C2—C1119.70 (17)C13—C14—H14119.8
C3—C2—H2120.1C15—C14—H14119.8
C1—C2—H2120.1C14—C15—C10121.04 (18)
O2—C3—C2124.22 (19)C14—C15—H15119.5
O2—C3—C4115.62 (17)C10—C15—H15119.5
C2—C3—C4120.16 (18)O1—C16—H16A109.5
C5—C4—C3119.46 (17)O1—C16—H16B109.5
C5—C4—H4120.3H16A—C16—H16B109.5
C3—C4—H4120.3O1—C16—H16C109.5
C4—C5—C6122.60 (18)H16A—C16—H16C109.5
C4—C5—H5118.7H16B—C16—H16C109.5
C6—C5—H5118.7O2—C17—H17A109.5
C1—C6—C5116.82 (17)O2—C17—H17B109.5
C1—C6—C7125.93 (15)H17A—C17—H17B109.5
C5—C6—C7117.21 (15)O2—C17—H17C109.5
O3—C7—C8120.85 (17)H17A—C17—H17C109.5
O3—C7—C6118.74 (16)H17B—C17—H17C109.5
C8—C7—C6120.39 (15)O4—C18—H18A109.5
C9—C8—C7122.73 (18)O4—C18—H18B109.5
C9—C8—H8120.1 (12)H18A—C18—H18B109.5
C7—C8—H8117.1 (12)O4—C18—H18C109.5
C8—C9—C10126.39 (18)H18A—C18—H18C109.5
C8—C9—H9118.9 (11)H18B—C18—H18C109.5
C10—C9—H9114.7 (11)O5—C19—H19A109.5
C15—C10—C11117.73 (17)O5—C19—H19B109.5
C15—C10—C9120.67 (17)H19A—C19—H19B109.5
C11—C10—C9121.57 (16)O5—C19—H19C109.5
C12—C11—C10121.57 (16)H19A—C19—H19C109.5
C12—C11—H11119.2H19B—C19—H19C109.5
C10—C11—H11119.2C1—O1—C16119.85 (15)
O4—C12—C11124.71 (16)C3—O2—C17118.05 (17)
O4—C12—C13115.65 (15)C12—O4—C18117.21 (14)
C11—C12—C13119.64 (17)C13—O5—C19117.86 (18)
O5—C13—C14125.41 (17)
O1—C1—C2—C3−177.22 (16)C15—C10—C11—C12−0.2 (2)
C6—C1—C2—C3−0.7 (3)C9—C10—C11—C12178.26 (15)
C1—C2—C3—O2178.59 (16)C10—C11—C12—O4−179.63 (15)
C1—C2—C3—C4−0.7 (3)C10—C11—C12—C13−0.4 (2)
O2—C3—C4—C5−177.74 (17)O4—C12—C13—O5−0.4 (2)
C2—C3—C4—C51.6 (3)C11—C12—C13—O5−179.68 (14)
C3—C4—C5—C6−1.2 (3)O4—C12—C13—C14−179.86 (15)
O1—C1—C6—C5177.78 (15)C11—C12—C13—C140.9 (3)
C2—C1—C6—C51.1 (2)O5—C13—C14—C15179.90 (17)
O1—C1—C6—C70.2 (2)C12—C13—C14—C15−0.7 (3)
C2—C1—C6—C7−176.47 (15)C13—C14—C15—C100.1 (3)
C4—C5—C6—C1−0.2 (3)C11—C10—C15—C140.3 (3)
C4—C5—C6—C7177.62 (16)C9—C10—C15—C14−178.11 (16)
C1—C6—C7—O3150.16 (17)C2—C1—O1—C16−12.8 (3)
C5—C6—C7—O3−27.4 (2)C6—C1—O1—C16170.51 (17)
C1—C6—C7—C8−31.7 (2)C2—C3—O2—C17−3.2 (3)
C5—C6—C7—C8150.79 (16)C4—C3—O2—C17176.09 (18)
O3—C7—C8—C9−1.9 (3)C11—C12—O4—C182.6 (2)
C6—C7—C8—C9179.96 (15)C13—C12—O4—C18−176.60 (15)
C7—C8—C9—C10−176.58 (15)C14—C13—O5—C19−3.6 (3)
C8—C9—C10—C15178.36 (17)C12—C13—O5—C19176.98 (16)
C8—C9—C10—C110.0 (3)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C8—H8···O10.96 (2)2.29 (2)2.813 (3)113.6 (15)
C18—H18B···O3i0.962.463.253 (3)140

Symmetry codes: (i) x, −y+1/2, z+1/2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HG2688).

References

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