organic compounds
(E)-1-(2,4,6-Trimethoxyphenyl)pent-1-en-3-one
aDepartment of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium
*Correspondence e-mail: frank.blockhuys@ua.ac.be
The title compound, C14H18O4, was obtained unintentionally as the major product of an attempted synthesis of (E,E)-2,5-bis[2-(2,4,6-trimethoxyphenyl)ethenyl]pyrazine. The crystal packing features layers based on two weak C—H⋯O hydrogen bonds involving the O atom of the carbonyl group and two Omethoxy⋯Cmethoxy interactions [3.109 (2) Å]. The sheets are interconnected via methoxy–methoxy dimers and C—H⋯π interactions.
Related literature
For related compounds containing the Ph—CH=CH—CO— fragment, see: Zhang et al. (2008); Degen & Bolte (1999); Zonouzi et al. (2009); Wang et al. (2005). For π-bridged donor–acceptor–donor systems as candidates for organic light-emitting diodes and their non-linear optical properties, see Liu et al. (2001); Grimsdale et al. (1997); Chemla (1987). For a description of the Cambridge Structural Database, see: Allen (2002).
Experimental
Crystal data
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Data collection
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Refinement
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Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999), Mercury (Macrae et al., 2008) and PLATON (Spek, 2009).
Supporting information
10.1107/S1600536810034641/zl2296sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536810034641/zl2296Isup2.hkl
A solution of sodium (1.0 g, 0.04 mol) in ethanol (50 ml) was added dropwise to a solution of 2,4,6-trimethoxybenzaldehyde (5.6 g, 0.04 mol) and 2,5-dimethylpyrazine (2.2 g, 0.02 mol) in ethanol (150 ml) at room temperature and the reaction mixture was heated under reflux for 4 h. The resulting fluorescent yellow solution was poured into 500 ml of ice water and the precipitate was filtered off and isomerized to the all-E form in p-xylene with a catalytic amount of iodine. Crystals suitable for X-ray diffraction were grown by slow evaporation of a THF solution. The yield was 2.3 g (46%). M.p. (uncorrected) 401 K. 1H NMR (CDCl3, 400 MHz, TMS): δ 7.63 (td, 8 and 0.4 Hz, H5), 8.18 (ddd, 8, 2 and 1 Hz, H6), 8.27 (ddd, 8, 2 and 1 Hz, H4), 8.62 (td, 2 and 0.4 Hz, H2), H4 and H6 appear to be magnetically equivalent. 13C NMR (CDCl3, 100 MHz, TMS): δ 121.59 (C2), 124.54 (C5), 130.24 (C6), 132.32 (C4), 142.46 (C1), 148.53 (C3).
Hydrogen atoms were placed in calculated positions and refined as riding with C—H distances of 0.93 Å.
Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell
CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999), Mercury (Macrae et al., 2008) and PLATON (Spek, 2009).Fig. 1. : Molecular structure of the title compound showing the numbering scheme. Displacement ellipsoids are drawn at the 50% probability level; hydrogen atoms are represented by spheres with an arbitrary radius. | |
Fig. 2. : Sheets formed by weak hydrogen bonds and Omethoxy···Cmethoxy interactions. | |
Fig. 3. : Interactions responsible for the stabilization of the crystal packing in the direction perpendicular to the the generated sheets. |
C14H18O4 | Z = 2 |
Mr = 250.28 | F(000) = 268 |
Triclinic, P1 | Dx = 1.281 Mg m−3 |
Hall symbol: -P 1 | Melting point: 401 K |
a = 6.8626 (8) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 8.297 (1) Å | Cell parameters from 25 reflections |
c = 12.068 (2) Å | θ = 5.8–10.7° |
α = 71.96 (1)° | µ = 0.09 mm−1 |
β = 84.28 (1)° | T = 293 K |
γ = 84.90 (1)° | Prism, yellow |
V = 648.88 (15) Å3 | 0.3 × 0.24 × 0.18 mm |
Enraf–Nonius CAD-4 diffractometer | Rint = 0.020 |
Radiation source: fine-focus sealed tube | θmax = 25.3°, θmin = 1.8° |
Graphite monochromator | h = −8→8 |
non–profiled ω/2θ scans | k = −9→9 |
4732 measured reflections | l = −14→14 |
2366 independent reflections | 3 standard reflections every 60 min |
1589 reflections with > 2/s(I) | intensity decay: none |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.106 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0495P)2 + 0.1212P] where P = (Fo2 + 2Fc2)/3 |
2366 reflections | (Δ/σ)max < 0.001 |
166 parameters | Δρmax = 0.14 e Å−3 |
0 restraints | Δρmin = −0.17 e Å−3 |
C14H18O4 | γ = 84.90 (1)° |
Mr = 250.28 | V = 648.88 (15) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.8626 (8) Å | Mo Kα radiation |
b = 8.297 (1) Å | µ = 0.09 mm−1 |
c = 12.068 (2) Å | T = 293 K |
α = 71.96 (1)° | 0.3 × 0.24 × 0.18 mm |
β = 84.28 (1)° |
Enraf–Nonius CAD-4 diffractometer | Rint = 0.020 |
4732 measured reflections | 3 standard reflections every 60 min |
2366 independent reflections | intensity decay: none |
1589 reflections with > 2/s(I) |
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.106 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.14 e Å−3 |
2366 reflections | Δρmin = −0.17 e Å−3 |
166 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C12 | 1.6553 (3) | −0.2420 (2) | 0.97422 (19) | 0.0572 (5) | |
H12A | 1.6978 | −0.1867 | 1.0259 | 0.086* | |
H12B | 1.7585 | −0.2453 | 0.9149 | 0.086* | |
H12C | 1.6235 | −0.3558 | 1.0179 | 0.086* | |
O2 | 0.41445 (17) | 0.31488 (16) | 0.60482 (12) | 0.0544 (4) | |
O1 | 0.90913 (18) | −0.12493 (15) | 0.63577 (11) | 0.0498 (3) | |
O3 | 0.95452 (17) | 0.26141 (15) | 0.84353 (11) | 0.0508 (4) | |
C2 | 0.8301 (2) | 0.0153 (2) | 0.66303 (15) | 0.0389 (4) | |
C1 | 0.9334 (2) | 0.0684 (2) | 0.73980 (14) | 0.0373 (4) | |
O4 | 1.4852 (2) | −0.34752 (17) | 0.81476 (13) | 0.0675 (4) | |
C3 | 0.6593 (2) | 0.1019 (2) | 0.61907 (15) | 0.0434 (4) | |
H3 | 0.5942 | 0.0657 | 0.5679 | 0.052* | |
C7 | 1.1125 (2) | −0.0161 (2) | 0.79054 (14) | 0.0383 (4) | |
H7 | 1.1607 | 0.0323 | 0.8414 | 0.046* | |
C6 | 0.8527 (2) | 0.2139 (2) | 0.76858 (14) | 0.0375 (4) | |
C8 | 1.2193 (2) | −0.1515 (2) | 0.77646 (16) | 0.0440 (4) | |
H8 | 1.1771 | −0.2042 | 0.7262 | 0.053* | |
C5 | 0.6805 (2) | 0.3019 (2) | 0.72569 (15) | 0.0405 (4) | |
H5 | 0.6307 | 0.3975 | 0.7462 | 0.049* | |
C9 | 1.3985 (2) | −0.2232 (2) | 0.83457 (15) | 0.0414 (4) | |
C21 | 0.3216 (3) | 0.4540 (3) | 0.63919 (19) | 0.0590 (5) | |
H21A | 0.2956 | 0.4200 | 0.7226 | 0.088* | |
H21B | 0.2003 | 0.4891 | 0.6027 | 0.088* | |
H21C | 0.4061 | 0.5469 | 0.6155 | 0.088* | |
C10 | 1.4756 (3) | −0.1447 (2) | 0.91735 (15) | 0.0427 (4) | |
H10A | 1.3731 | −0.1395 | 0.9778 | 0.051* | |
H10B | 1.5081 | −0.0292 | 0.8748 | 0.051* | |
C4 | 0.5856 (2) | 0.2428 (2) | 0.65167 (15) | 0.0408 (4) | |
C31 | 0.8968 (3) | 0.4174 (2) | 0.86731 (18) | 0.0548 (5) | |
H31A | 0.8984 | 0.5088 | 0.7953 | 0.082* | |
H31B | 0.9863 | 0.4371 | 0.9174 | 0.082* | |
H31C | 0.7667 | 0.4115 | 0.9053 | 0.082* | |
C11 | 0.8077 (3) | −0.1881 (2) | 0.56160 (17) | 0.0535 (5) | |
H11A | 0.6802 | −0.2198 | 0.5982 | 0.080* | |
H11B | 0.8809 | −0.2856 | 0.5486 | 0.080* | |
H11C | 0.7938 | −0.1015 | 0.4882 | 0.080* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C12 | 0.0540 (12) | 0.0567 (12) | 0.0682 (13) | 0.0125 (9) | −0.0247 (10) | −0.0277 (10) |
O2 | 0.0432 (7) | 0.0571 (8) | 0.0729 (9) | 0.0161 (6) | −0.0281 (6) | −0.0321 (7) |
O1 | 0.0480 (7) | 0.0507 (7) | 0.0651 (8) | 0.0121 (6) | −0.0228 (6) | −0.0368 (7) |
O3 | 0.0475 (7) | 0.0496 (7) | 0.0707 (9) | 0.0177 (6) | −0.0281 (6) | −0.0391 (7) |
C2 | 0.0383 (9) | 0.0378 (9) | 0.0456 (10) | 0.0026 (7) | −0.0072 (7) | −0.0201 (8) |
C1 | 0.0339 (9) | 0.0384 (9) | 0.0434 (10) | 0.0034 (7) | −0.0085 (7) | −0.0177 (8) |
O4 | 0.0663 (9) | 0.0600 (9) | 0.0944 (11) | 0.0310 (7) | −0.0347 (8) | −0.0504 (8) |
C3 | 0.0412 (10) | 0.0478 (10) | 0.0495 (11) | 0.0017 (8) | −0.0167 (8) | −0.0241 (9) |
C7 | 0.0358 (9) | 0.0394 (9) | 0.0452 (10) | 0.0036 (7) | −0.0106 (7) | −0.0199 (8) |
C6 | 0.0355 (9) | 0.0389 (9) | 0.0431 (9) | 0.0025 (7) | −0.0095 (7) | −0.0190 (8) |
C8 | 0.0435 (10) | 0.0436 (10) | 0.0538 (11) | 0.0070 (8) | −0.0168 (8) | −0.0261 (9) |
C5 | 0.0385 (9) | 0.0364 (9) | 0.0498 (10) | 0.0063 (7) | −0.0096 (8) | −0.0181 (8) |
C9 | 0.0405 (9) | 0.0371 (9) | 0.0497 (11) | 0.0073 (8) | −0.0087 (8) | −0.0190 (8) |
C21 | 0.0445 (11) | 0.0633 (13) | 0.0740 (14) | 0.0208 (9) | −0.0200 (10) | −0.0298 (11) |
C10 | 0.0436 (10) | 0.0390 (9) | 0.0485 (10) | 0.0055 (8) | −0.0107 (8) | −0.0175 (8) |
C4 | 0.0330 (9) | 0.0431 (10) | 0.0463 (10) | 0.0042 (7) | −0.0098 (8) | −0.0132 (8) |
C31 | 0.0526 (11) | 0.0507 (11) | 0.0773 (14) | 0.0156 (9) | −0.0255 (10) | −0.0415 (11) |
C11 | 0.0562 (11) | 0.0568 (12) | 0.0629 (12) | 0.0039 (9) | −0.0177 (9) | −0.0385 (10) |
C12—C10 | 1.514 (2) | C7—H7 | 0.9300 |
C12—H12A | 0.9600 | C6—C5 | 1.390 (2) |
C12—H12B | 0.9600 | C8—C9 | 1.463 (2) |
C12—H12C | 0.9600 | C8—H8 | 0.9300 |
O2—C4 | 1.3620 (19) | C5—C4 | 1.381 (2) |
O2—C21 | 1.423 (2) | C5—H5 | 0.9300 |
O1—C2 | 1.3584 (19) | C9—C10 | 1.508 (2) |
O1—C11 | 1.4287 (19) | C21—H21A | 0.9600 |
O3—C6 | 1.3629 (19) | C21—H21B | 0.9600 |
O3—C31 | 1.4253 (19) | C21—H21C | 0.9600 |
C2—C3 | 1.382 (2) | C10—H10A | 0.9700 |
C2—C1 | 1.412 (2) | C10—H10B | 0.9700 |
C1—C6 | 1.409 (2) | C31—H31A | 0.9600 |
C1—C7 | 1.452 (2) | C31—H31B | 0.9600 |
O4—C9 | 1.2206 (19) | C31—H31C | 0.9600 |
C3—C4 | 1.385 (2) | C11—H11A | 0.9600 |
C3—H3 | 0.9300 | C11—H11B | 0.9600 |
C7—C8 | 1.332 (2) | C11—H11C | 0.9600 |
C10—C12—H12A | 109.5 | O4—C9—C8 | 118.99 (15) |
C10—C12—H12B | 109.5 | O4—C9—C10 | 120.39 (15) |
H12A—C12—H12B | 109.5 | C8—C9—C10 | 120.62 (14) |
C10—C12—H12C | 109.5 | O2—C21—H21A | 109.5 |
H12A—C12—H12C | 109.5 | O2—C21—H21B | 109.5 |
H12B—C12—H12C | 109.5 | H21A—C21—H21B | 109.5 |
C4—O2—C21 | 118.09 (13) | O2—C21—H21C | 109.5 |
C2—O1—C11 | 118.44 (13) | H21A—C21—H21C | 109.5 |
C6—O3—C31 | 119.00 (12) | H21B—C21—H21C | 109.5 |
O1—C2—C3 | 122.66 (14) | C9—C10—C12 | 113.02 (14) |
O1—C2—C1 | 115.88 (14) | C9—C10—H10A | 109.0 |
C3—C2—C1 | 121.46 (14) | C12—C10—H10A | 109.0 |
C6—C1—C2 | 116.34 (14) | C9—C10—H10B | 109.0 |
C6—C1—C7 | 118.79 (15) | C12—C10—H10B | 109.0 |
C2—C1—C7 | 124.87 (14) | H10A—C10—H10B | 107.8 |
C2—C3—C4 | 119.62 (15) | O2—C4—C5 | 124.12 (15) |
C2—C3—H3 | 120.2 | O2—C4—C3 | 114.18 (14) |
C4—C3—H3 | 120.2 | C5—C4—C3 | 121.69 (15) |
C8—C7—C1 | 130.83 (16) | O3—C31—H31A | 109.5 |
C8—C7—H7 | 114.6 | O3—C31—H31B | 109.5 |
C1—C7—H7 | 114.6 | H31A—C31—H31B | 109.5 |
O3—C6—C5 | 121.97 (14) | O3—C31—H31C | 109.5 |
O3—C6—C1 | 115.08 (13) | H31A—C31—H31C | 109.5 |
C5—C6—C1 | 122.94 (14) | H31B—C31—H31C | 109.5 |
C7—C8—C9 | 124.60 (15) | O1—C11—H11A | 109.5 |
C7—C8—H8 | 117.7 | O1—C11—H11B | 109.5 |
C9—C8—H8 | 117.7 | H11A—C11—H11B | 109.5 |
C4—C5—C6 | 117.93 (15) | O1—C11—H11C | 109.5 |
C4—C5—H5 | 121.0 | H11A—C11—H11C | 109.5 |
C6—C5—H5 | 121.0 | H11B—C11—H11C | 109.5 |
C11—O1—C2—C3 | −2.0 (2) | C7—C1—C6—C5 | −179.07 (16) |
C11—O1—C2—C1 | 177.92 (16) | C1—C7—C8—C9 | −179.80 (17) |
O1—C2—C1—C6 | 179.96 (15) | O3—C6—C5—C4 | −178.96 (16) |
C3—C2—C1—C6 | −0.1 (2) | C1—C6—C5—C4 | 0.0 (3) |
O1—C2—C1—C7 | −0.5 (3) | C7—C8—C9—O4 | −179.72 (18) |
C3—C2—C1—C7 | 179.42 (17) | C7—C8—C9—C10 | 0.1 (3) |
O1—C2—C3—C4 | 179.20 (16) | O4—C9—C10—C12 | −3.5 (3) |
C1—C2—C3—C4 | −0.8 (3) | C8—C9—C10—C12 | 176.69 (17) |
C6—C1—C7—C8 | −178.60 (19) | C21—O2—C4—C5 | −3.7 (3) |
C2—C1—C7—C8 | 1.9 (3) | C21—O2—C4—C3 | 176.19 (16) |
C31—O3—C6—C5 | −7.9 (3) | C6—C5—C4—O2 | 178.94 (16) |
C31—O3—C6—C1 | 173.02 (16) | C6—C5—C4—C3 | −0.9 (3) |
C2—C1—C6—O3 | 179.50 (15) | C2—C3—C4—O2 | −178.58 (16) |
C7—C1—C6—O3 | 0.0 (2) | C2—C3—C4—C5 | 1.3 (3) |
C2—C1—C6—C5 | 0.5 (3) |
Cg is the centroid of the C1–C6 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···O4i | 0.93 | 2.59 | 3.517 (2) | 177 |
C31—H31C···O4i | 0.96 | 2.70 | 3.286 (2) | 120 |
C21—H21C···O2ii | 0.96 | 2.76 | 3.419 (2) | 127 |
C11—H11A···O4iii | 0.96 | 2.75 | 3.557 (2) | 142 |
C12—H12C···O4iv | 0.96 | 2.76 | 3.706 (2) | 167 |
C10—H10B···Cgv | 0.97 | 2.77 | 3.59 | 142 |
Symmetry codes: (i) x−1, y+1, z; (ii) −x+1, −y+1, −z+1; (iii) x−1, y, z; (iv) −x+3, −y−1, −z+2; (v) x+1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C14H18O4 |
Mr | 250.28 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 6.8626 (8), 8.297 (1), 12.068 (2) |
α, β, γ (°) | 71.96 (1), 84.28 (1), 84.90 (1) |
V (Å3) | 648.88 (15) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.3 × 0.24 × 0.18 |
Data collection | |
Diffractometer | Enraf–Nonius CAD-4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [ > 2/s(I)] reflections | 4732, 2366, 1589 |
Rint | 0.020 |
(sin θ/λ)max (Å−1) | 0.602 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.106, 1.03 |
No. of reflections | 2366 |
No. of parameters | 166 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.14, −0.17 |
Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999), Mercury (Macrae et al., 2008) and PLATON (Spek, 2009).
Cg is the centroid of the C1–C6 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···O4i | 0.93 | 2.59 | 3.517 (2) | 177 |
C31—H31C···O4i | 0.96 | 2.70 | 3.286 (2) | 120 |
C21—H21C···O2ii | 0.96 | 2.76 | 3.419 (2) | 127 |
C11—H11A···O4iii | 0.96 | 2.75 | 3.557 (2) | 142 |
C12—H12C···O4iv | 0.96 | 2.76 | 3.706 (2) | 167 |
C10—H10B···Cgv | 0.97 | 2.77 | 3.59 | 142 |
Symmetry codes: (i) x−1, y+1, z; (ii) −x+1, −y+1, −z+1; (iii) x−1, y, z; (iv) −x+3, −y−1, −z+2; (v) x+1, y, z. |
Acknowledgements
AC wishes to thank the Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT) for a predoctoral grant. Financial support by the University of Antwerp under grant No. GOA-2404 is gratefully acknowledged.
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π-Bridged donor-acceptor-donor (A—D—A) systems are promising candidates for electronic applications such as organic light-emitting diodes (Liu et al., 2001; Grimsdale et al., 1997), as they are expected to have electronic properties similar to those of conventional OPV-type systems but with a red-shifted emission spectrum. Moreover, due to their high degree of conjugation, these A—D—A oligomers are also excellent candidates for organic non-linear optic (NLO) media with a high second-order hyperpolarizability, γ (Chemla, 1987). In an attempt to synthesize the A—D—A system E,E-2,5-bis[2-(2,4,6-trimethoxyphenyl)ethenyl]pyrazine from dimethylpyrazine and the relevant benzaldehyde under standard condensation conditions, (E)-1-(2,4,6-trimethoxyphenyl)pent-1-en-3-one (Fig. 1) was obtained as the major product. In this compound the C=C bond is not disordered, in contrast to what is the case in the 3-methoxy-4-acetoxyphenyl derivative YODGOO (Zhang et al., 2008) and the molecule adopts the anti conformation indicating that there are no energetically beneficial intermolecular contacts favouring the syn conformation as in the unsubstituted DIBNEH (Degen & Bolte, 1999). The title compound displays two weak intramolecular hydrogen bonds involving the methoxy groups in the ortho positions of the phenyl ring, one in a five- and one in a six-membered ring configuration. In contrast, in the 2-hydroxy-5-bromophenyl derivative NORGOR (Zonouzi et al., 2009) a less stable six-membered ring configuration is observed due to the competing strong intermolecular O—H···O hydrogen bond with an adjacent molecule. In the 2-hydroxyphenyl derivative FONKEZ (Wang et al., 2005), the more favourable five-membered ring configuration is also seen. The packing of the title compound is determined in first instance by contacts between the methoxy groups. Two molecules (symmetry-related via an inversion centre) are connected into a dimer involving O2 and C11 of the methoxy groups in the 2- and 4-positions [C11···O2i, 3.109 (2) Å, 178.33 (12)°, symm. code i = 1 - x, -y, 1 - z] (Fig. 2); note that the C···O—C angle is almost linear. Sheets are then generated through two weak hydrogen bonds involving H5 (Table 1, entry 1) and H31C (entry 2) contacting the oxygen atom of the carbonyl group (O4). These sheets are then interconnected by four additional weak hydrogen bonds (Fig. 3): H21C and O2 are involved in a second dimer formation (entry 3), H11A and H12C contact the oxygen atom of the carbonyl (O4, entries 4 and 5) and H10B of the methylene group next to the carbonyl group generates a CH···π interaction with a nearby phenyl ring (entry 6).