6-Meth­oxy-2-(2-meth­oxy­naphthalen-1-yl)-4H-chromen-4-one

Sung, J.

doi:10.1107/S2414314618012774

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 3| Part 9| September 2018| x181277

https://doi.org/10.1107/S2414314618012774

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6-Methoxy-2-(2-methoxynaphthalen-1-yl)-4H-chromen-4-one

Jiha Sung ^a ^*

^aDepartment of Applied Chemistry, Dongduk Women's University, Seoul 136-714, Republic of Korea
^*Correspondence e-mail: dddklab@gmail.com

Edited by J. Simpson, University of Otago, New Zealand (Received 5 September 2018; accepted 10 September 2018; online 14 September 2018)

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 skeletal structure and are a sub-class of the flavonoids. 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. 1). 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 ).

Figure 1
The flavone skeleton and some common naturally occurring flavones.

The 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)°].

Figure 2
The molecular structure of the title compound, showing the atom-labelling scheme, with displacement ellipsoids drawn at the 30% probability level.

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).

Table 1
Hydrogen-bond geometry (Å, °)

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.

Figure 3
A view of an inversion dimer formed by pair of C17—H17⋯O2 hydrogen bonds (dashed lines) in the crystal structure of the title compound. For clarity only those H atoms involved in hydrogen bonding are shown.

Figure 4
A partial view of the crystal structure of the title compound showing double chains of molecules formed along [010]. Intermolecular C—H⋯O hydrogen bonds are shown as dashed lines.

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.

Figure 5
A synthetic scheme for the preparation of the title compound.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₂₁H₁₆O₄
M_r	332.34
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	223
a, b, c (Å)	7.9937 (5), 9.3819 (6), 12.2131 (8)
α, β, γ (°)	72.552 (3), 86.895 (3), 67.288 (3)
V (Å³)	804.06 (9)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	0.10
Crystal size (mm)	0.19 × 0.10 × 0.05

Data collection
Diffractometer	Bruker PHOTON 100 CMOS
Absorption correction	Multi-scan (SADABS; Bruker, 2012 )
T_min, T_max	0.693, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	22094, 4000, 2036
R_int	0.108
(sin θ/λ)_max (Å⁻¹)	0.667

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.056, 0.133, 1.02
No. of reflections	4000
No. of parameters	228
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.23, −0.23
Computer programs: APEX2 and SAINT (Bruker, 2012), SHELXS (Sheldrick, 2008 ), SHELXL2014/7 (Sheldrick, 2015 ), SHELXTL (Sheldrick, 2008) and publCIF (Westrip, 2010 ).

Structural data

CCDC reference: 1866882

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314618012774/sj4189sup1.cif

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

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2012); cell refinement: 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).

6-Methoxy-2-(2-methoxynaphthalen-1-yl)-4H-chromen-4-one top

Crystal data top

C₂₁H₁₆O₄	Z = 2
M_r = 332.34	F(000) = 348
Triclinic, P1	D_x = 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

Data collection top

Bruker PHOTON 100 CMOS diffractometer	2036 reflections with I > 2σ(I)
φ and ω scans	R_int = 0.108
Absorption correction: multi-scan (SADABS; Bruker, 2012)	θ_max = 28.3°, θ_min = 2.5°
T_min = 0.693, T_max = 0.746	h = −10→10
22094 measured reflections	k = −12→12
4000 independent reflections	l = −16→16

Refinement top

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(F_o²) + (0.0466P)² + 0.238P] where P = (F_o² + 2F_c²)/3
S = 1.02	(Δ/σ)_max = 0.001
4000 reflections	Δρ_max = 0.23 e Å⁻³
228 parameters	Δρ_min = −0.23 e Å⁻³

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
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*

Atomic displacement parameters (Å²) top

	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)

Geometric parameters (Å, º) top

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)

Hydrogen-bond geometry (Å, º) top

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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