2-Meth­oxy­naphthalene-1,4-dione

Abstract

The title compound, C₁₁H₈O₃, was isolated from Impatiens balsamina plants (balsam, LIB) grown in our laboratory. The two six-membered rings of the naphthalene-1,4-dione unit are coplanar [maximum deviation = 0.009 (1) Å]. The O and C atoms of the meth­oxy substituent also lie close to the naphthalene plane, with deviations of 0.0090 (2) and 0.047 (2) Å, respectively.

Related literature

For background to compounds extracted from Impatiens balsamina, see: Ding et al. (2008 ▶). For the anti­microbial activity of flavonol and naphtho­quinone derivatives, see: Yang et al. (2001 ▶). For their anti-anaphylaxis properties, see: Yoshimi et al. (2003 ▶); Ishiguro et al. (1994 ▶) and for their use as anti-inflammatories, see: Hisae & Kyoko (2002 ▶). For standard bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

• C₁₁H₈O₃

• M _r = 188.17

• Monoclinic,

• a = 3.904 (3) Å

• b = 7.662 (6) Å

• c = 28.81 (2) Å

• β = 93.562 (7)°

• V = 860.1 (12) ų

• Z = 4

• Mo Kα radiation

• μ = 0.11 mm⁻¹

• T = 296 K

• 0.20 × 0.20 × 0.10 mm

Data collection

• Enraf–Nonius CAD-4 diffractometer

• Absorption correction: ψ scan (North et al., 1968 ▶. T _min = 0.979, T _max = 0.989

• 7068 measured reflections

• 2082 independent reflections

• 1458 reflections with I > 2σ(I)

• R _int = 0.032

• 3 standard reflections every 200 reflections intensity decay: 1%

Refinement

• R[F ² > 2σ(F ²)] = 0.056

• wR(F ²) = 0.136

• S = 1.08

• 2082 reflections

• 128 parameters

• H-atom parameters constrained

• Δρ_max = 0.19 e Å⁻³

• Δρ_min = −0.25 e Å⁻³

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

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

supplementary crystallographic information

Comment

Modern chemical and pharmacological studies have identified flavonol and naphthoquinone derivatives, some of which have strong antimicrobial (Yang et al., 2001) anti-anaphylaxis (Yoshimi et al., 2003, Ishiguro et al., 1994) and anti-inflammatory properties (Hisae & Kyoko, 2002). We have purified and identified an active component of the Impatiens balsamina plant (balsam, LIB) which was grown in our laboratory (Ding et al., 2008) and authenticated by Professor Yao Zhensheng (Zhejiang Traditional Chinese Medicinal University). The molecular structure of the title compound is shown in Fig. 1. In the crystal, all bond lengths are within normal ranges (Allen et al., 1987). The C1···C4,C9,C10 and C5···C10 rings of the naphthalene-1,4-dione unit are co-planar, maximum deviation 0.009 (1) Å. The O2 and C11 atoms of the methoxy substituent also lie close to the naphthalene plane with deviations of 0.0090 (2) Å and 0.047 (2) Å respectively.

Experimental

Dried leaves (200 g) of Impatiens balsamina were crushed, soaked with 55% alcohol (1500 ml) for 24 h and then reflux extracted for 40 min (1500 ml\3). Extracts were filtered and vacuum evaporated. In addition, 200 g of dried leaves were directly reflux extracted using chloroform (3000 ml\2). Next these extracts were filtered, combined, vacuum evaporated and the residue dried for further use. A portion of residue was re-chromatographed on silica gel using a petroleum ether-acetone (8:2) system and the isolated product was recrystallized from chloroform to yield the active component as light yellow crystals.

Refinement

H atoms were positioned geometrically and refined using the riding-model approximation, with C—H = 0.93–0.97 Å, O—H = 0.82 Å, and U_iso(H) = 1.2U_eq(C) or U_iso(H) = 1.5U_eq(O).

Figures

Fig. 1.

The molecular structure of the title compounds with atom labels and 50% probability displacement ellipsoids for non-hydrogen atoms.

Crystal data

C11H8O3	F(000) = 392
Mr = 188.17	Dx = 1.453 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -p 2ybc	Cell parameters from 1421 reflections
a = 3.904 (3) Å	θ = 3.0–26.7°
b = 7.662 (6) Å	µ = 0.11 mm−1
c = 28.81 (2) Å	T = 296 K
β = 93.562 (7)°	Block, yellow
V = 860.1 (12) Å3	0.20 × 0.20 × 0.10 mm
Z = 4

Data collection

Enrfa–Nonius CAD-4 diffractometer	1458 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.032
graphite	θmax = 28.3°, θmin = 2.8°
ω/2θ scans	h = −5→5
Absorption correction: ψ scan (North et al., 1968.	k = −10→10
Tmin = 0.979, Tmax = 0.989	l = −38→36
7068 measured reflections	3 standard reflections every 200 reflections
2082 independent reflections	intensity decay: 1%

Refinement

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)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.136	H-atom parameters constrained
S = 1.08	w = 1/[σ2(Fo2) + (0.0386P)2 + 0.5448P] where P = (Fo2 + 2Fc2)/3
2082 reflections	(Δ/σ)max < 0.001
128 parameters	Δρmax = 0.19 e Å−3
0 restraints	Δρmin = −0.25 e Å−3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O2	0.5248 (4)	1.29754 (19)	0.09145 (5)	0.0460 (4)
C10	0.8859 (5)	0.7924 (3)	0.12534 (7)	0.0351 (5)
C1	0.6106 (5)	1.0740 (3)	0.14687 (7)	0.0389 (5)
C9	0.7444 (5)	0.8979 (3)	0.15900 (7)	0.0347 (4)
C2	0.6487 (5)	1.1357 (3)	0.09790 (7)	0.0369 (5)
O3	1.0374 (5)	0.7687 (2)	0.04711 (5)	0.0549 (5)
C5	1.0035 (6)	0.6270 (3)	0.13751 (8)	0.0423 (5)
H5	1.0976	0.5566	0.1153	0.051*
O1	0.4735 (5)	1.1666 (2)	0.17443 (6)	0.0636 (5)
C3	0.7874 (5)	1.0345 (3)	0.06610 (7)	0.0393 (5)
H3	0.8047	1.0774	0.0361	0.047*
C6	0.9824 (6)	0.5657 (3)	0.18238 (8)	0.0483 (6)
H6	1.0607	0.4542	0.1902	0.058*
C4	0.9122 (5)	0.8589 (3)	0.07713 (7)	0.0384 (5)
C7	0.8444 (6)	0.6705 (3)	0.21567 (8)	0.0482 (6)
H7	0.8321	0.6295	0.2459	0.058*
C8	0.7251 (6)	0.8354 (3)	0.20418 (7)	0.0426 (5)
H8	0.6317	0.9049	0.2266	0.051*
C11	0.5484 (6)	1.3721 (3)	0.04595 (8)	0.0508 (6)
H11A	0.7849	1.3784	0.0388	0.076*
H11B	0.4516	1.4874	0.0454	0.076*
H11C	0.4243	1.3005	0.0233	0.076*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O2	0.0583 (10)	0.0385 (8)	0.0422 (8)	0.0075 (7)	0.0122 (7)	−0.0003 (7)
C10	0.0342 (11)	0.0366 (11)	0.0347 (10)	−0.0011 (8)	0.0035 (8)	−0.0051 (8)
C1	0.0426 (12)	0.0375 (11)	0.0379 (11)	−0.0023 (9)	0.0124 (9)	−0.0080 (9)
C9	0.0341 (10)	0.0352 (10)	0.0354 (10)	−0.0059 (8)	0.0057 (8)	−0.0060 (8)
C2	0.0383 (11)	0.0331 (11)	0.0395 (11)	−0.0010 (8)	0.0053 (9)	−0.0030 (8)
O3	0.0747 (12)	0.0500 (10)	0.0418 (9)	0.0127 (9)	0.0185 (8)	−0.0096 (7)
C5	0.0440 (12)	0.0378 (11)	0.0453 (12)	0.0035 (9)	0.0037 (9)	−0.0076 (9)
O1	0.0953 (14)	0.0488 (10)	0.0502 (10)	0.0166 (9)	0.0325 (9)	−0.0034 (8)
C3	0.0444 (12)	0.0416 (11)	0.0324 (10)	0.0007 (9)	0.0070 (9)	−0.0023 (9)
C6	0.0534 (14)	0.0383 (12)	0.0528 (14)	0.0013 (10)	−0.0003 (11)	0.0024 (10)
C4	0.0372 (11)	0.0406 (12)	0.0379 (11)	−0.0007 (9)	0.0076 (9)	−0.0091 (9)
C7	0.0553 (14)	0.0495 (13)	0.0400 (12)	−0.0014 (11)	0.0037 (10)	0.0053 (10)
C8	0.0473 (13)	0.0440 (12)	0.0375 (11)	−0.0036 (10)	0.0102 (9)	−0.0049 (9)
C11	0.0607 (15)	0.0482 (13)	0.0442 (13)	0.0094 (11)	0.0090 (11)	0.0078 (10)

Geometric parameters (Å, °)

O2—C2	1.340 (3)	C5—H5	0.9300
O2—C11	1.438 (3)	C3—C4	1.459 (3)
C10—C5	1.386 (3)	C3—H3	0.9300
C10—C9	1.402 (3)	C6—C7	1.385 (3)
C10—C4	1.489 (3)	C6—H6	0.9300
C1—O1	1.213 (2)	C7—C8	1.380 (3)
C1—C9	1.481 (3)	C7—H7	0.9300
C1—C2	1.504 (3)	C8—H8	0.9300
C9—C8	1.394 (3)	C11—H11A	0.9600
C2—C3	1.340 (3)	C11—H11B	0.9600
O3—C4	1.232 (2)	C11—H11C	0.9600
C5—C6	1.383 (3)
C2—O2—C11	116.82 (16)	C5—C6—C7	119.9 (2)
C5—C10—C9	119.40 (19)	C5—C6—H6	120.0
C5—C10—C4	120.52 (18)	C7—C6—H6	120.0
C9—C10—C4	120.07 (19)	O3—C4—C3	120.4 (2)
O1—C1—C9	122.80 (19)	O3—C4—C10	121.1 (2)
O1—C1—C2	120.2 (2)	C3—C4—C10	118.50 (17)
C9—C1—C2	116.96 (16)	C8—C7—C6	120.3 (2)
C8—C9—C10	119.6 (2)	C8—C7—H7	119.8
C8—C9—C1	119.66 (18)	C6—C7—H7	119.8
C10—C9—C1	120.70 (18)	C7—C8—C9	120.1 (2)
O2—C2—C3	126.77 (19)	C7—C8—H8	119.9
O2—C2—C1	111.40 (16)	C9—C8—H8	119.9
C3—C2—C1	121.83 (19)	O2—C11—H11A	109.5
C6—C5—C10	120.6 (2)	O2—C11—H11B	109.5
C6—C5—H5	119.7	H11A—C11—H11B	109.5
C10—C5—H5	119.7	O2—C11—H11C	109.5
C2—C3—C4	121.89 (19)	H11A—C11—H11C	109.5
C2—C3—H3	119.1	H11B—C11—H11C	109.5
C4—C3—H3	119.1
C5—C10—C9—C8	0.2 (3)	C4—C10—C5—C6	179.4 (2)
C4—C10—C9—C8	−179.15 (19)	O2—C2—C3—C4	−179.6 (2)
C5—C10—C9—C1	−178.86 (19)	C1—C2—C3—C4	−0.5 (3)
C4—C10—C9—C1	1.8 (3)	C10—C5—C6—C7	−0.4 (3)
O1—C1—C9—C8	−2.2 (3)	C2—C3—C4—O3	179.7 (2)
C2—C1—C9—C8	178.25 (19)	C2—C3—C4—C10	−0.5 (3)
O1—C1—C9—C10	176.9 (2)	C5—C10—C4—O3	0.2 (3)
C2—C1—C9—C10	−2.7 (3)	C9—C10—C4—O3	179.6 (2)
C11—O2—C2—C3	−1.2 (3)	C5—C10—C4—C3	−179.5 (2)
C11—O2—C2—C1	179.59 (18)	C9—C10—C4—C3	−0.1 (3)
O1—C1—C2—O2	1.7 (3)	C5—C6—C7—C8	0.6 (4)
C9—C1—C2—O2	−178.74 (17)	C6—C7—C8—C9	−0.3 (3)
O1—C1—C2—C3	−177.6 (2)	C10—C9—C8—C7	−0.1 (3)
C9—C1—C2—C3	2.0 (3)	C1—C9—C8—C7	179.0 (2)
C9—C10—C5—C6	0.0 (3)