2',4'-Dihydr­oxy-5',6'-dimethoxy­chalcone

The title compound, C₁₇H₁₆O₅, an (E)-1-(4,6-dihydroxy-2,3-dimeth­oxy­phen­yl)-3-phenyl­prop-2-en-1-one, was isolated from a plant of genus Cryptocarya costata. The mol­ecule adopts a trans configuration with respect to the positions of the benzene ring and the dihydroxy­dimethoxy­benzaldehyde fragment about the olefinic C=C double bond. The mol­ecules are linked by inter­molecular hydrogen bonds to form ribbons extending parallel to the b axis.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.053
• wR factor = 0.130
• Data-to-parameter ratio = 13.8

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S1. Comment

A number of chalcones containing hydroxyl groups at C(2'), C(2',4') or C(2',4) have been known to be potential as therapeutic agents against infections with methicilin-resistant Staphylococcus aureus strains (Alcaraz et al., 2000). Therefore, some chalcone derivatives have been successfully synthesized including 2',4'-dihydroxy-5',6'-dimethoxychalcone (I) (Bhaskar & Seshadri, 1974). However, only a few structures of naturally occurring chalcones isolated from plants have been reported. Some examples are 2',6'-dihydroxy-4,4'-dimethoxychalcone (II) from the plant Pityrogramma chrysophylla (Nilsson, 1961; Schmalle et al., 1990), Flemiculosin (III) from the leaves of Flemingia fruticolose (Bhattacharyya et al., 1999) and (E)-1-(2-hydroxy-3-(4-dimethoxyphenyl)prop-2-en-one (IV) (Krishna et al., 2005). In the course of our study on the secondary metabolites from Cryptocarya sp. growing in Indonesia, suitable crystals of (I) for X-ray investigation were obtained.

As in most substituted chalcones, the molecule of the title compound (I) is not planar. The substituted benzene ring (C1'-C6')/O2/O3/O4/O5 is essentially planar with maximum deviation of 0.054 (2) Å for atom O2 from the least square plane. It is inclined by 28.22 (10)° to the propenylbenzene fragment [C1–C9] (maximum deviation 0.022 (2) Å at atom C8). The O–Me bonds, O2–C10 and O3–C11, are perpendicular to the benzene C1'–C6' plane with torsion angles C10–O2–C6'–C5' and C11–O3–C5'–C6' of 88.5 (3) and 65.93 (3)°, respectively. The carbonyl group, C9═O1, is in a cis configuration with respect to the olefenic C7═C8 double bond, a typical chalcone compound.

The bond lengths and angles of the molecule are in normal ranges (Table 1) and in agreement with all the analogues with slight variation on the C═O bond length. The C9═O1 bond length is slightly shorter than that in (II) and (IV) [1.264 (3) and 1.2538 (17) Å, respectively]. The presence of five intramolecular hydrogen bonds viz. O4–H4B···O3, O5–H5B···O1, C7–H7A···O1, C8–H8A···O2 and C11–H11C···O2 (Table 2) may contribute to the stability and planarity of the molecule. In the structure, the molecules are linked by intermolecular hydrogen bonds (symmetry codes as given in Table 2) forming ribbons extended parallel to b axis (Fig. 2).

S2. Experimental

Barks from the tree Cryptocarya costata Bl. were collected from The National Garden of Leralindu, Central Sulawesi, Indonesia. The voucher specimen (E-377L) was deposited at the herbarium of Faculty of Sciences, University of Tadulako, Central Sulawesi. The powdered dried tree barks (2.5 kg) of C. costata were macerated with methanol at room temperature for 24 h. The mixture was filtered and the methanol filtrate was evaporated under reduced pressure to give a concentrated methanol extract. To the extract distilled water was added, and the aqueous methanol extract was partitioned into CHCl₃ and ethyl acetate to give CHCl₃ (140 g) and ethyl acetate (40 g) soluble fractions. A portion (20 g) of the CHCl₃ fraction was fractionated using column vacuum chromatography (silica gel, eluted with n-hexane–ethyl acetate = 9:1–1:1) to give six major fractions A—F. Repeated purification of fraction C (230 g) by radial chromatography (n-hexane–EtOAc = 7:3) gave compound (I). Recrystallization from methanol afforded yellow crystals (50 g) with melting point 440–442 K.

S3. Refinement

H atoms were located in the difference map and repositioned geometrically with C–H = 0.93 − 0.96 Å and O–H = 0.86 Å. They were constrained to ride on their parent atoms, with U_iso(H) = 1.2 (1.5 for CH₃ and OH) times U_eq(C,O).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL, PARST (Nardelli, 1995) and PLATON (Spek, 2003).

Figures

	Fig. 1. The molecular structure of the title compound, (I), with the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. The dashed lines indicate the intramolecular O–H···O and C–H···O hydrogen bonds.
	Fig. 2. A packing diagram for (I). The intermolecular C–H···O and O–H···O hydrogen bonding interactions are shown as dashed lines.

2',4'-Dihydroxy-5',6'-dimethoxychalcone

Crystal data

C17H16O5	F(000) = 1264
Mr = 300.30	Dx = 1.353 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 3566 reflections
a = 12.360 (2) Å	θ = 2.0–25.5°
b = 7.1688 (14) Å	µ = 0.10 mm^−1
c = 33.275 (6) Å	T = 298 K
V = 2948.3 (10) Å^3	Block, yellow
Z = 8	0.48 × 0.45 × 0.19 mm

Data collection

Bruker SMART APEX area-detector diffractometer	2747 independent reflections
Radiation source: fine-focus sealed tube	2137 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
Detector resolution: 83.66 pixels mm^-1	θmax = 25.5°, θmin = 2.0°
ω scans	h = −14→14
Absorption correction: multi-scan (SADABS; Bruker, 2000)	k = −8→8
Tmin = 0.953, Tmax = 0.981	l = −33→40
14651 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.130	H-atom parameters constrained
S = 1.11	w = 1/[σ^2(Fo^2) + (0.0545P)^2 + 0.9791P] where P = (Fo^2 + 2Fc^2)/3
2747 reflections	(Δ/σ)max < 0.001
199 parameters	Δρmax = 0.18 e Å^−3
0 restraints	Δρmin = −0.15 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.

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

	x	y	z	Uiso*/Ueq
O1	0.18787 (12)	0.0964 (3)	0.36742 (5)	0.0636 (5)
O2	0.52405 (11)	0.1270 (2)	0.38143 (4)	0.0534 (4)
O3	0.60992 (11)	0.2219 (3)	0.45505 (4)	0.0577 (5)
O4	0.47337 (12)	0.2885 (3)	0.51833 (4)	0.0717 (6)
H4B	0.5396	0.2830	0.5175	0.108*
O5	0.16773 (11)	0.1899 (2)	0.43929 (5)	0.0591 (5)
H5B	0.1488	0.1546	0.4169	0.089*
C2	0.30111 (18)	−0.0632 (3)	0.22705 (7)	0.0536 (6)
H2A	0.2350	−0.1197	0.2325	0.064*
C3	0.3440 (2)	−0.0750 (4)	0.18884 (7)	0.0606 (7)
H3A	0.3075	−0.1414	0.1690	0.073*
C4	0.4400 (2)	0.0106 (3)	0.18010 (7)	0.0576 (6)
H4A	0.4685	0.0039	0.1543	0.069*
C5	0.49407 (19)	0.1066 (3)	0.20968 (7)	0.0552 (6)
H5A	0.5592	0.1654	0.2037	0.066*
C6	0.45255 (17)	0.1165 (3)	0.24799 (7)	0.0494 (5)
H6A	0.4904	0.1809	0.2678	0.059*
C1	0.35465 (16)	0.0314 (3)	0.25750 (6)	0.0428 (5)
C7	0.30642 (17)	0.0404 (3)	0.29747 (6)	0.0457 (5)
H7A	0.2397	−0.0178	0.3005	0.055*
C8	0.34651 (17)	0.1216 (3)	0.32986 (6)	0.0480 (5)
H8A	0.4138	0.1794	0.3283	0.058*
C9	0.28749 (16)	0.1230 (3)	0.36831 (6)	0.0470 (5)
C1'	0.34106 (16)	0.1603 (3)	0.40662 (6)	0.0419 (5)
C6'	0.45453 (15)	0.1668 (3)	0.41239 (6)	0.0419 (5)
C5'	0.49921 (16)	0.2141 (3)	0.44887 (6)	0.0461 (5)
C4'	0.43233 (17)	0.2486 (3)	0.48180 (6)	0.0508 (6)
C3'	0.32199 (16)	0.2408 (4)	0.47744 (6)	0.0523 (6)
H3B	0.2775	0.2660	0.4993	0.063*
C2'	0.27679 (16)	0.1961 (3)	0.44104 (6)	0.0449 (5)
C11	0.66396 (19)	0.3645 (5)	0.43294 (7)	0.0740 (8)
H11A	0.7400	0.3608	0.4388	0.111*
H11B	0.6353	0.4840	0.4404	0.111*
H11C	0.6530	0.3447	0.4047	0.111*
C10	0.5553 (2)	−0.0645 (5)	0.37975 (9)	0.0874 (9)
H10A	0.6037	−0.0833	0.3576	0.131*
H10B	0.4921	−0.1409	0.3762	0.131*
H10C	0.5909	−0.0983	0.4043	0.131*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0402 (9)	0.0979 (14)	0.0527 (10)	−0.0085 (8)	−0.0023 (7)	−0.0049 (9)
O2	0.0430 (8)	0.0768 (12)	0.0403 (8)	0.0004 (8)	0.0073 (6)	−0.0037 (7)
O3	0.0355 (8)	0.0945 (13)	0.0430 (9)	−0.0035 (8)	−0.0019 (6)	0.0104 (8)
O4	0.0476 (9)	0.1305 (17)	0.0369 (8)	−0.0046 (10)	−0.0006 (7)	−0.0042 (9)
O5	0.0349 (8)	0.0897 (13)	0.0526 (9)	0.0000 (8)	0.0037 (7)	−0.0027 (8)
C2	0.0517 (13)	0.0544 (14)	0.0546 (14)	−0.0120 (11)	−0.0028 (10)	−0.0007 (11)
C3	0.0718 (16)	0.0651 (17)	0.0449 (13)	−0.0077 (13)	−0.0078 (11)	−0.0078 (11)
C4	0.0701 (15)	0.0585 (15)	0.0442 (13)	0.0018 (13)	0.0054 (11)	0.0004 (11)
C5	0.0531 (14)	0.0549 (15)	0.0577 (14)	−0.0072 (11)	0.0079 (11)	0.0006 (12)
C6	0.0471 (12)	0.0525 (13)	0.0488 (12)	−0.0054 (10)	−0.0013 (10)	−0.0044 (11)
C1	0.0443 (11)	0.0412 (12)	0.0428 (12)	0.0003 (9)	−0.0024 (9)	0.0017 (9)
C7	0.0415 (11)	0.0471 (13)	0.0483 (13)	−0.0030 (10)	−0.0004 (9)	0.0021 (10)
C8	0.0408 (11)	0.0590 (14)	0.0442 (12)	−0.0056 (10)	−0.0030 (9)	0.0057 (11)
C9	0.0391 (12)	0.0545 (14)	0.0473 (12)	−0.0019 (10)	−0.0014 (9)	0.0019 (10)
C1'	0.0396 (11)	0.0478 (13)	0.0384 (11)	−0.0008 (9)	0.0020 (9)	0.0049 (9)
C6'	0.0387 (11)	0.0526 (13)	0.0343 (10)	0.0017 (9)	0.0049 (8)	0.0061 (9)
C5'	0.0351 (11)	0.0638 (15)	0.0394 (11)	−0.0010 (10)	0.0011 (9)	0.0083 (10)
C4'	0.0465 (12)	0.0708 (16)	0.0351 (11)	−0.0029 (11)	−0.0014 (10)	0.0054 (10)
C3'	0.0428 (12)	0.0748 (16)	0.0393 (12)	0.0001 (11)	0.0091 (9)	0.0015 (11)
C2'	0.0348 (11)	0.0548 (14)	0.0451 (12)	0.0010 (9)	0.0028 (9)	0.0069 (10)
C11	0.0515 (15)	0.116 (2)	0.0543 (15)	−0.0231 (15)	0.0008 (12)	0.0133 (15)
C10	0.080 (2)	0.099 (2)	0.083 (2)	0.0330 (18)	0.0161 (16)	−0.0099 (18)

Geometric parameters (Å, º)

O1—C9	1.246 (2)	C1—C7	1.459 (3)
O2—C6'	1.371 (2)	C7—C8	1.321 (3)
O2—C10	1.428 (3)	C7—H7A	0.9300
O3—C5'	1.385 (2)	C8—C9	1.473 (3)
O3—C11	1.426 (3)	C8—H8A	0.9300
O4—C4'	1.348 (2)	C9—C1'	1.461 (3)
O4—H4B	0.8200	C1'—C6'	1.416 (3)
O5—C2'	1.350 (2)	C1'—C2'	1.417 (3)
O5—H5B	0.8200	C6'—C5'	1.376 (3)
C2—C3	1.380 (3)	C5'—C4'	1.395 (3)
C2—C1	1.387 (3)	C4'—C3'	1.373 (3)
C2—H2A	0.9300	C3'—C2'	1.372 (3)
C3—C4	1.367 (3)	C3'—H3B	0.9300
C3—H3A	0.9300	C11—H11A	0.9600
C4—C5	1.375 (3)	C11—H11B	0.9600
C4—H4A	0.9300	C11—H11C	0.9600
C5—C6	1.376 (3)	C10—H10A	0.9600
C5—H5A	0.9300	C10—H10B	0.9600
C6—C1	1.392 (3)	C10—H10C	0.9600
C6—H6A	0.9300
C6'—O2—C10	113.48 (19)	C6'—C1'—C2'	116.09 (18)
C5'—O3—C11	114.54 (18)	C6'—C1'—C9	124.96 (18)
C4'—O4—H4B	109.5	C2'—C1'—C9	118.95 (18)
C2'—O5—H5B	109.5	O2—C6'—C5'	117.55 (17)
C3—C2—C1	121.3 (2)	O2—C6'—C1'	120.79 (18)
C3—C2—H2A	119.3	C5'—C6'—C1'	121.66 (18)
C1—C2—H2A	119.3	C6'—C5'—O3	122.50 (18)
C4—C3—C2	120.1 (2)	C6'—C5'—C4'	119.92 (19)
C4—C3—H3A	119.9	O3—C5'—C4'	117.53 (18)
C2—C3—H3A	119.9	O4—C4'—C3'	118.56 (19)
C3—C4—C5	119.6 (2)	O4—C4'—C5'	121.53 (19)
C3—C4—H4A	120.2	C3'—C4'—C5'	119.9 (2)
C5—C4—H4A	120.2	C2'—C3'—C4'	120.5 (2)
C4—C5—C6	120.5 (2)	C2'—C3'—H3B	119.7
C4—C5—H5A	119.7	C4'—C3'—H3B	119.7
C6—C5—H5A	119.7	O5—C2'—C3'	116.89 (18)
C5—C6—C1	120.8 (2)	O5—C2'—C1'	121.27 (19)
C5—C6—H6A	119.6	C3'—C2'—C1'	121.83 (19)
C1—C6—H6A	119.6	O3—C11—H11A	109.5
C2—C1—C6	117.59 (19)	O3—C11—H11B	109.5
C2—C1—C7	119.51 (19)	H11A—C11—H11B	109.5
C6—C1—C7	122.90 (19)	O3—C11—H11C	109.5
C8—C7—C1	127.6 (2)	H11A—C11—H11C	109.5
C8—C7—H7A	116.2	H11B—C11—H11C	109.5
C1—C7—H7A	116.2	O2—C10—H10A	109.5
C7—C8—C9	121.7 (2)	O2—C10—H10B	109.5
C7—C8—H8A	119.1	H10A—C10—H10B	109.5
C9—C8—H8A	119.1	O2—C10—H10C	109.5
O1—C9—C1'	119.76 (19)	H10A—C10—H10C	109.5
O1—C9—C8	117.89 (19)	H10B—C10—H10C	109.5
C1'—C9—C8	122.32 (18)
C1—C2—C3—C4	−1.4 (4)	C2'—C1'—C6'—C5'	−3.1 (3)
C2—C3—C4—C5	0.7 (4)	C9—C1'—C6'—C5'	175.9 (2)
C3—C4—C5—C6	0.3 (4)	O2—C6'—C5'—O3	−0.2 (3)
C4—C5—C6—C1	−0.7 (4)	C1'—C6'—C5'—O3	−179.7 (2)
C3—C2—C1—C6	1.0 (3)	O2—C6'—C5'—C4'	−177.4 (2)
C3—C2—C1—C7	−180.0 (2)	C1'—C6'—C5'—C4'	3.1 (3)
C5—C6—C1—C2	0.0 (3)	C11—O3—C5'—C6'	65.9 (3)
C5—C6—C1—C7	−179.0 (2)	C11—O3—C5'—C4'	−116.8 (2)
C2—C1—C7—C8	179.0 (2)	C6'—C5'—C4'—O4	177.5 (2)
C6—C1—C7—C8	−2.0 (4)	O3—C5'—C4'—O4	0.2 (3)
C1—C7—C8—C9	178.7 (2)	C6'—C5'—C4'—C3'	−2.0 (4)
C7—C8—C9—O1	−20.8 (3)	O3—C5'—C4'—C3'	−179.3 (2)
C7—C8—C9—C1'	161.3 (2)	O4—C4'—C3'—C2'	−178.4 (2)
O1—C9—C1'—C6'	170.7 (2)	C5'—C4'—C3'—C2'	1.1 (4)
C8—C9—C1'—C6'	−11.5 (3)	C4'—C3'—C2'—O5	179.5 (2)
O1—C9—C1'—C2'	−10.3 (3)	C4'—C3'—C2'—C1'	−1.3 (4)
C8—C9—C1'—C2'	167.6 (2)	C6'—C1'—C2'—O5	−178.6 (2)
C10—O2—C6'—C5'	88.5 (3)	C9—C1'—C2'—O5	2.3 (3)
C10—O2—C6'—C1'	−92.0 (3)	C6'—C1'—C2'—C3'	2.3 (3)
C2'—C1'—C6'—O2	177.39 (19)	C9—C1'—C2'—C3'	−176.8 (2)
C9—C1'—C6'—O2	−3.6 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4B···O3	0.82	2.29	2.741 (2)	115
O5—H5B···O1	0.82	1.77	2.496 (2)	147
C7—H7A···O1	0.93	2.46	2.780 (3)	100
C8—H8A···O2	0.93	2.26	2.786 (3)	115
C11—H11C···O2	0.96	2.36	2.971 (3)	121
O4—H4B···O5^i	0.82	2.15	2.790 (2)	135
C3′—H3B···O3^ii	0.93	2.57	3.462 (3)	161
C11—H11B···O4^iii	0.96	2.52	3.420 (4)	156

Symmetry codes: (i) x+1/2, −y+1/2, −z+1; (ii) x−1/2, −y+1/2, −z+1; (iii) −x+1, −y+1, −z+1.