organic compounds
6-Methoxy-2-(2-methoxynaphthalen-1-yl)-4H-chromen-4-one
aDepartment of Applied Chemistry, Dongduk Women's University, Seoul 136-714, Republic of Korea
*Correspondence e-mail: dddklab@gmail.com
In the title compound, C21H16O4, the methoxy-substituted naphthalene ring system (r.m.s. deviation = 0.007 Å) is almost orthogonal to the 4H-chromenone skeleton (r.m.s. deviation = 0.012 Å) with a dihedral angle of 83.16 (4)° between them. In the crystal, inversion dimers are linked by pairs of C—H⋯O hydrogen bonds that generate R22(18) loops and additional C—H⋯O interactions connect the dimers into double chains of molecules along the b-axis direction.
Keywords: crystal structure; flavone; C—H⋯O hydrogen bonds; inversion dimers.
CCDC reference: 1866882
Structure description
Flavones have a 2-phenylchromen-4-one ). A recent review described their broad spectrum of biological activities and pharmaceutical applications (Singh et al., 2014). Naphthyl flavones result from the replacement of the phenyl ring at the 2-position of a flavone with a naphthyl ring system, and the resulting compounds also show versatile biological activities (Ahn et al., 2017; Lee et al., 2016).
and are a sub-class of the Common flavones include Apigenin, Chrysin, Zapotin, and Wogonin, depending on the placement of the hydroxy or methoxy group substituents at different positions on the flavone backbone (Fig. 1The molecular structure of the title compound, C21H16O4, is shown in Fig. 2. The dihedral angle formed between the plane of the methoxy-substituted naphthalene ring system (r.m.s. deviation = 0.007 Å) and the plane of the 4H-chromenone skeleton (r.m.s. deviation = 0.012 Å) is 83.16 (4)°. This contrasts sharply with the situation found for 5,6-dihydroxy-7,8-dimethoxyflavone (Goyal et al., 2018) and ethyl 2-[2-(4-oxo-4H-chromen-2-yl)phenoxy]acetate (Jing et al., 2013), which have substituted benzene or phenyl substituents at the 2-positions of the chromenone units, where the corresponding dihedral angles are 4.9 (1) and 1.89 (6)°, respectively. The methoxy groups are almost coplanar with the benzene ring and naphthalene ring system to which they are connected [torsion angles C8—C7—O4—C21 = −2.7 (3)°; C12—C11—O3—C20 = −1.8 (3)°].
In the crystal, inversion dimers form through pairs of C17—H17⋯O2 hydrogen bonds and generate R22(18) loops (Table 1, Fig. 3). Inversion dimers also result from C8—H8⋯O2 and C21—H21C⋯O2 hydrogen bonds enclosing R22(10) and R22(16) rings, respectively. These contacts combine to form double chains of molecules along [010] (Table 1, Fig. 4).
Synthesis and crystallization
To a mixture of 2-hydroxy-5-methoxyacetophenone (498 mg, 3 mmol) and 2-methoxy-1-naphthaldehyde (558 mg, 3 mmol) in 30 ml of ethanol, 3 ml of aq. KOH (50%) were added and stirred at room temperature for 48 h. (Fig. 5). After the completion of the reaction, the reaction mixture was poured into ice water (50 ml) and acidified with 3 M HCl (pH = 3). The resulting solid was filtered, washed with water and purified from ethanol to give the intermediate chalcone I (Fig. 5). To a solution of compound I (334 mg, 1 mmol) in 5 ml of DMSO, a catalytic amount of iodine (I2, 0.25 eq.) was added as an oxidant and the mixture was refluxed for 2 h at 413 K, and then was cooled to room temperature. The reaction mixture was poured into crushed ice–water (50 ml) and the resulting solid was separated by filtration and washed with water. Recrystallization of the solid from ethanol solution gave crystals of the title compound.
Refinement
Crystal data, data collection and structure .
details are summarized in Table 2Structural data
CCDC reference: 1866882
https://doi.org/10.1107/S2414314618012774/sj4189sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314618012774/sj4189Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314618012774/sj4189Isup3.cml
Data collection: APEX2 (Bruker, 2012); cell
SAINT (Bruker, 2012); data reduction: SAINT (Bruker, 2012); program(s) used to solve structure: SHELXS (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014/7 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).C21H16O4 | Z = 2 |
Mr = 332.34 | F(000) = 348 |
Triclinic, P1 | Dx = 1.373 Mg m−3 |
a = 7.9937 (5) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.3819 (6) Å | Cell parameters from 2767 reflections |
c = 12.2131 (8) Å | θ = 2.6–24.7° |
α = 72.552 (3)° | µ = 0.10 mm−1 |
β = 86.895 (3)° | T = 223 K |
γ = 67.288 (3)° | Block, yellow |
V = 804.06 (9) Å3 | 0.19 × 0.10 × 0.05 mm |
Bruker PHOTON 100 CMOS diffractometer | 2036 reflections with I > 2σ(I) |
φ and ω scans | Rint = 0.108 |
Absorption correction: multi-scan (SADABS; Bruker, 2012) | θmax = 28.3°, θmin = 2.5° |
Tmin = 0.693, Tmax = 0.746 | h = −10→10 |
22094 measured reflections | k = −12→12 |
4000 independent reflections | l = −16→16 |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.056 | H-atom parameters constrained |
wR(F2) = 0.133 | w = 1/[σ2(Fo2) + (0.0466P)2 + 0.238P] where P = (Fo2 + 2Fc2)/3 |
S = 1.02 | (Δ/σ)max = 0.001 |
4000 reflections | Δρmax = 0.23 e Å−3 |
228 parameters | Δρmin = −0.23 e Å−3 |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.1945 (3) | 0.3234 (2) | 0.87676 (18) | 0.0298 (5) | |
C2 | 0.3261 (3) | 0.2885 (3) | 0.79292 (18) | 0.0314 (5) | |
H2 | 0.4178 | 0.3295 | 0.7853 | 0.038* | |
C3 | 0.3232 (3) | 0.2003 (2) | 0.72571 (18) | 0.0282 (5) | |
O1 | 0.19798 (18) | 0.13238 (17) | 0.73275 (12) | 0.0306 (4) | |
C4 | 0.0659 (3) | 0.1606 (2) | 0.81089 (17) | 0.0264 (5) | |
C5 | −0.0605 (3) | 0.0921 (3) | 0.81328 (19) | 0.0331 (5) | |
H5 | −0.0537 | 0.0295 | 0.7645 | 0.040* | |
C6 | −0.1957 (3) | 0.1172 (3) | 0.88803 (19) | 0.0334 (5) | |
H6 | −0.2813 | 0.0703 | 0.8910 | 0.040* | |
C7 | −0.2078 (3) | 0.2119 (3) | 0.95984 (18) | 0.0305 (5) | |
C8 | −0.0830 (3) | 0.2807 (3) | 0.95611 (18) | 0.0294 (5) | |
H8 | −0.0917 | 0.3453 | 1.0037 | 0.035* | |
C9 | 0.0575 (3) | 0.2545 (2) | 0.88118 (17) | 0.0250 (5) | |
O2 | 0.1948 (2) | 0.4058 (2) | 0.93853 (14) | 0.0459 (5) | |
C10 | 0.4467 (3) | 0.1712 (2) | 0.63266 (18) | 0.0276 (5) | |
C11 | 0.4075 (3) | 0.2897 (3) | 0.52793 (19) | 0.0344 (5) | |
C12 | 0.5218 (3) | 0.2689 (3) | 0.43725 (19) | 0.0397 (6) | |
H12 | 0.4944 | 0.3505 | 0.3660 | 0.048* | |
C13 | 0.6723 (3) | 0.1296 (3) | 0.4537 (2) | 0.0383 (6) | |
H13 | 0.7474 | 0.1161 | 0.3926 | 0.046* | |
C14 | 0.7191 (3) | 0.0050 (3) | 0.55912 (19) | 0.0309 (5) | |
C15 | 0.8762 (3) | −0.1391 (3) | 0.5769 (2) | 0.0404 (6) | |
H15 | 0.9523 | −0.1534 | 0.5163 | 0.049* | |
C16 | 0.9197 (3) | −0.2574 (3) | 0.6798 (2) | 0.0450 (6) | |
H16 | 1.0260 | −0.3517 | 0.6902 | 0.054* | |
C17 | 0.8055 (3) | −0.2389 (3) | 0.7707 (2) | 0.0393 (6) | |
H17 | 0.8351 | −0.3214 | 0.8416 | 0.047* | |
C18 | 0.6521 (3) | −0.1019 (3) | 0.75662 (19) | 0.0318 (5) | |
H18 | 0.5771 | −0.0911 | 0.8181 | 0.038* | |
C19 | 0.6037 (3) | 0.0250 (2) | 0.65053 (18) | 0.0274 (5) | |
O3 | 0.2527 (2) | 0.4243 (2) | 0.51847 (14) | 0.0512 (5) | |
C20 | 0.2052 (4) | 0.5532 (3) | 0.4130 (2) | 0.0562 (8) | |
H20A | 0.2967 | 0.5996 | 0.3997 | 0.084* | |
H20B | 0.0881 | 0.6361 | 0.4172 | 0.084* | |
H20C | 0.1986 | 0.5117 | 0.3502 | 0.084* | |
O4 | −0.3469 (2) | 0.22502 (19) | 1.03115 (14) | 0.0433 (4) | |
C21 | −0.3570 (3) | 0.3119 (3) | 1.1107 (2) | 0.0519 (7) | |
H21A | −0.2475 | 0.2575 | 1.1619 | 0.078* | |
H21B | −0.4619 | 0.3159 | 1.1553 | 0.078* | |
H21C | −0.3683 | 0.4213 | 1.0690 | 0.078* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0296 (11) | 0.0288 (12) | 0.0336 (13) | −0.0125 (10) | 0.0065 (10) | −0.0123 (11) |
C2 | 0.0271 (11) | 0.0381 (13) | 0.0366 (13) | −0.0178 (10) | 0.0085 (10) | −0.0161 (11) |
C3 | 0.0260 (11) | 0.0274 (12) | 0.0289 (12) | −0.0092 (9) | 0.0023 (9) | −0.0072 (10) |
O1 | 0.0307 (8) | 0.0356 (9) | 0.0316 (9) | −0.0161 (7) | 0.0077 (6) | −0.0154 (7) |
C4 | 0.0256 (11) | 0.0265 (11) | 0.0253 (12) | −0.0090 (9) | 0.0039 (9) | −0.0070 (10) |
C5 | 0.0354 (12) | 0.0337 (13) | 0.0358 (14) | −0.0157 (10) | 0.0036 (10) | −0.0153 (11) |
C6 | 0.0307 (12) | 0.0347 (13) | 0.0402 (14) | −0.0183 (10) | 0.0024 (10) | −0.0113 (11) |
C7 | 0.0263 (11) | 0.0321 (12) | 0.0333 (13) | −0.0140 (10) | 0.0072 (9) | −0.0077 (11) |
C8 | 0.0310 (11) | 0.0297 (12) | 0.0287 (12) | −0.0122 (10) | 0.0047 (9) | −0.0105 (10) |
C9 | 0.0267 (11) | 0.0228 (11) | 0.0220 (11) | −0.0081 (9) | 0.0017 (9) | −0.0038 (9) |
O2 | 0.0468 (10) | 0.0592 (11) | 0.0583 (11) | −0.0333 (9) | 0.0239 (8) | −0.0413 (10) |
C10 | 0.0274 (11) | 0.0293 (12) | 0.0279 (12) | −0.0111 (9) | 0.0049 (9) | −0.0115 (10) |
C11 | 0.0327 (12) | 0.0334 (13) | 0.0339 (14) | −0.0087 (10) | 0.0031 (10) | −0.0115 (11) |
C12 | 0.0460 (14) | 0.0421 (15) | 0.0271 (13) | −0.0162 (12) | 0.0066 (11) | −0.0069 (11) |
C13 | 0.0379 (13) | 0.0499 (15) | 0.0323 (14) | −0.0190 (12) | 0.0138 (10) | −0.0190 (12) |
C14 | 0.0288 (11) | 0.0360 (13) | 0.0332 (13) | −0.0146 (10) | 0.0054 (10) | −0.0158 (11) |
C15 | 0.0330 (12) | 0.0447 (15) | 0.0479 (16) | −0.0129 (11) | 0.0119 (11) | −0.0246 (14) |
C16 | 0.0336 (13) | 0.0376 (14) | 0.0581 (18) | −0.0040 (11) | 0.0010 (12) | −0.0191 (14) |
C17 | 0.0396 (13) | 0.0332 (13) | 0.0430 (15) | −0.0131 (11) | −0.0044 (11) | −0.0084 (12) |
C18 | 0.0329 (12) | 0.0349 (13) | 0.0332 (13) | −0.0167 (10) | 0.0033 (10) | −0.0137 (11) |
C19 | 0.0281 (11) | 0.0316 (12) | 0.0288 (12) | −0.0158 (10) | 0.0032 (9) | −0.0128 (10) |
O3 | 0.0486 (10) | 0.0410 (10) | 0.0371 (10) | 0.0043 (8) | 0.0052 (8) | −0.0035 (8) |
C20 | 0.0662 (18) | 0.0378 (15) | 0.0396 (16) | −0.0009 (13) | −0.0063 (13) | −0.0010 (13) |
O4 | 0.0384 (9) | 0.0541 (11) | 0.0532 (11) | −0.0287 (8) | 0.0218 (8) | −0.0272 (9) |
C21 | 0.0562 (16) | 0.0625 (18) | 0.0593 (18) | −0.0370 (14) | 0.0330 (14) | −0.0361 (15) |
C1—O2 | 1.232 (2) | C12—C13 | 1.360 (3) |
C1—C2 | 1.442 (3) | C12—H12 | 0.9400 |
C1—C9 | 1.463 (3) | C13—C14 | 1.405 (3) |
C2—C3 | 1.335 (3) | C13—H13 | 0.9400 |
C2—H2 | 0.9400 | C14—C15 | 1.413 (3) |
C3—O1 | 1.366 (2) | C14—C19 | 1.419 (3) |
C3—C10 | 1.482 (3) | C15—C16 | 1.358 (3) |
O1—C4 | 1.386 (2) | C15—H15 | 0.9400 |
C4—C9 | 1.385 (3) | C16—C17 | 1.407 (3) |
C4—C5 | 1.387 (3) | C16—H16 | 0.9400 |
C5—C6 | 1.372 (3) | C17—C18 | 1.363 (3) |
C5—H5 | 0.9400 | C17—H17 | 0.9400 |
C6—C7 | 1.399 (3) | C18—C19 | 1.421 (3) |
C6—H6 | 0.9400 | C18—H18 | 0.9400 |
C7—O4 | 1.365 (2) | O3—C20 | 1.425 (3) |
C7—C8 | 1.375 (3) | C20—H20A | 0.9700 |
C8—C9 | 1.403 (3) | C20—H20B | 0.9700 |
C8—H8 | 0.9400 | C20—H20C | 0.9700 |
C10—C11 | 1.375 (3) | O4—C21 | 1.425 (3) |
C10—C19 | 1.423 (3) | C21—H21A | 0.9700 |
C11—O3 | 1.364 (2) | C21—H21B | 0.9700 |
C11—C12 | 1.408 (3) | C21—H21C | 0.9700 |
O2—C1—C2 | 123.39 (19) | C11—C12—H12 | 120.3 |
O2—C1—C9 | 122.48 (18) | C12—C13—C14 | 122.2 (2) |
C2—C1—C9 | 114.13 (18) | C12—C13—H13 | 118.9 |
C3—C2—C1 | 122.8 (2) | C14—C13—H13 | 118.9 |
C3—C2—H2 | 118.6 | C13—C14—C15 | 122.3 (2) |
C1—C2—H2 | 118.6 | C13—C14—C19 | 118.63 (19) |
C2—C3—O1 | 122.70 (18) | C15—C14—C19 | 119.0 (2) |
C2—C3—C10 | 124.79 (19) | C16—C15—C14 | 121.4 (2) |
O1—C3—C10 | 112.45 (17) | C16—C15—H15 | 119.3 |
C3—O1—C4 | 118.21 (15) | C14—C15—H15 | 119.3 |
C9—C4—O1 | 122.29 (18) | C15—C16—C17 | 119.9 (2) |
C9—C4—C5 | 121.54 (18) | C15—C16—H16 | 120.0 |
O1—C4—C5 | 116.16 (18) | C17—C16—H16 | 120.0 |
C6—C5—C4 | 118.83 (19) | C18—C17—C16 | 120.4 (2) |
C6—C5—H5 | 120.6 | C18—C17—H17 | 119.8 |
C4—C5—H5 | 120.6 | C16—C17—H17 | 119.8 |
C5—C6—C7 | 120.9 (2) | C17—C18—C19 | 121.1 (2) |
C5—C6—H6 | 119.6 | C17—C18—H18 | 119.5 |
C7—C6—H6 | 119.6 | C19—C18—H18 | 119.5 |
O4—C7—C8 | 125.22 (19) | C14—C19—C18 | 118.15 (19) |
O4—C7—C6 | 114.82 (18) | C14—C19—C10 | 118.8 (2) |
C8—C7—C6 | 119.94 (19) | C18—C19—C10 | 123.00 (18) |
C7—C8—C9 | 119.92 (19) | C11—O3—C20 | 118.98 (18) |
C7—C8—H8 | 120.0 | O3—C20—H20A | 109.5 |
C9—C8—H8 | 120.0 | O3—C20—H20B | 109.5 |
C4—C9—C8 | 118.91 (18) | H20A—C20—H20B | 109.5 |
C4—C9—C1 | 119.84 (17) | O3—C20—H20C | 109.5 |
C8—C9—C1 | 121.25 (18) | H20A—C20—H20C | 109.5 |
C11—C10—C19 | 120.18 (18) | H20B—C20—H20C | 109.5 |
C11—C10—C3 | 118.58 (18) | C7—O4—C21 | 116.54 (17) |
C19—C10—C3 | 121.24 (19) | O4—C21—H21A | 109.5 |
O3—C11—C10 | 115.91 (19) | O4—C21—H21B | 109.5 |
O3—C11—C12 | 123.3 (2) | H21A—C21—H21B | 109.5 |
C10—C11—C12 | 120.79 (19) | O4—C21—H21C | 109.5 |
C13—C12—C11 | 119.4 (2) | H21A—C21—H21C | 109.5 |
C13—C12—H12 | 120.3 | H21B—C21—H21C | 109.5 |
O2—C1—C2—C3 | −179.3 (2) | C19—C10—C11—O3 | 179.00 (18) |
C9—C1—C2—C3 | −0.3 (3) | C3—C10—C11—O3 | −1.5 (3) |
C1—C2—C3—O1 | −1.7 (3) | C19—C10—C11—C12 | −0.3 (3) |
C1—C2—C3—C10 | 175.3 (2) | C3—C10—C11—C12 | 179.1 (2) |
C2—C3—O1—C4 | 1.9 (3) | O3—C11—C12—C13 | −179.1 (2) |
C10—C3—O1—C4 | −175.43 (17) | C10—C11—C12—C13 | 0.2 (3) |
C3—O1—C4—C9 | 0.0 (3) | C11—C12—C13—C14 | −0.5 (3) |
C3—O1—C4—C5 | 178.68 (18) | C12—C13—C14—C15 | −179.3 (2) |
C9—C4—C5—C6 | −0.6 (3) | C12—C13—C14—C19 | 0.9 (3) |
O1—C4—C5—C6 | −179.32 (19) | C13—C14—C15—C16 | 179.5 (2) |
C4—C5—C6—C7 | 0.8 (3) | C19—C14—C15—C16 | −0.7 (3) |
C5—C6—C7—O4 | −179.0 (2) | C14—C15—C16—C17 | 1.0 (4) |
C5—C6—C7—C8 | −0.1 (3) | C15—C16—C17—C18 | −0.7 (4) |
O4—C7—C8—C9 | 178.1 (2) | C16—C17—C18—C19 | 0.0 (3) |
C6—C7—C8—C9 | −0.7 (3) | C13—C14—C19—C18 | 179.83 (19) |
O1—C4—C9—C8 | 178.45 (18) | C15—C14—C19—C18 | 0.1 (3) |
C5—C4—C9—C8 | −0.2 (3) | C13—C14—C19—C10 | −1.0 (3) |
O1—C4—C9—C1 | −1.9 (3) | C15—C14—C19—C10 | 179.25 (19) |
C5—C4—C9—C1 | 179.5 (2) | C17—C18—C19—C14 | 0.3 (3) |
C7—C8—C9—C4 | 0.8 (3) | C17—C18—C19—C10 | −178.8 (2) |
C7—C8—C9—C1 | −178.8 (2) | C11—C10—C19—C14 | 0.7 (3) |
O2—C1—C9—C4 | −179.0 (2) | C3—C10—C19—C14 | −178.74 (19) |
C2—C1—C9—C4 | 2.0 (3) | C11—C10—C19—C18 | 179.9 (2) |
O2—C1—C9—C8 | 0.7 (3) | C3—C10—C19—C18 | 0.4 (3) |
C2—C1—C9—C8 | −178.37 (19) | C10—C11—O3—C20 | 178.9 (2) |
C2—C3—C10—C11 | −80.7 (3) | C12—C11—O3—C20 | −1.8 (3) |
O1—C3—C10—C11 | 96.5 (2) | C8—C7—O4—C21 | −2.7 (3) |
C2—C3—C10—C19 | 98.8 (3) | C6—C7—O4—C21 | 176.17 (19) |
O1—C3—C10—C19 | −84.0 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8···O2i | 0.94 | 2.46 | 3.350 (2) | 157 |
C21—H21C···O2i | 0.97 | 2.49 | 3.266 (3) | 137 |
C17—H17···O2ii | 0.94 | 2.59 | 3.425 (3) | 149 |
Symmetry codes: (i) −x, −y+1, −z+2; (ii) −x+1, −y, −z+2. |
Acknowledgements
This work was supported by a Dongduk Women's University grant.
Funding information
Funding for this research was provided by: Dongduk Women's University.
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