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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 4| April 2010| Page o988
doi:10.1107/S1600536810011360

6,8-Di­iodo-5,7-dimeth­­oxy-4-methyl­coumarin

P. S. Pereira Silva,a Mehtab Parveen,b Zakia Khanam,b Akhtar Alib and M. Ramos Silvaa*

aCEMDRX, Physics Department, University of Coimbra, P-3004-516 Coimbra, Portugal, and bDepartment of Chemistry, Aligarh Muslim University, Aligarh 202 002, India
*Correspondence e-mail: psidonio@pollux.fis.uc.pt

(Received 24 March 2010; accepted 25 March 2010; online 31 March 2010)

In the title compound, C12H10I2O4, the meth­oxy groups are twisted considerably with respect to the plane of the aromatic ring [CH3—O—C—C torsion angles = −85.9 (3) and −92.8 (3)°]. In the crystal, mol­ecules are linked by weak C—H⋯O hydrogen bonds and O⋯I contacts [3.194 (2) Å].

Related literature

For the medicinal applications of coumarin derivatives, see: Lin et al. (2006[Lin, C. M., Huang, S. T., Lee, F. W., Sawkuo, H. & Lin, M. H. (2006). Bioorg. Med. Chem. 14, 4402-4409.]); Massimo et al. (2003[Massimo, C., Francesco, E., Federica, M., Carla, M. M., Prieto, G. S. & Carlos, R. J. (2003). Aust. J. Chem. 56, 59-60.]); Tyagi et al. (2003[Tyagi, A. K., Raj, H. G., Vohra, P., Gupta, G., Kumari, R., Kumar, P. & Gupta, R. K. (2003). Eur. J. Med. Chem. 40, 413-420.]); Nawrot-Modranka et al. (2006[Nawrot-Modranka, J., Nawrot, E. & Graczyk, J. (2006). Eur. J. Med. Chem. 41, 1301-1309.]); Sardari et al. (1999[Sardari, S., Mori, Y., Horita, K., Micetich, R. G., Nishibe, S. & Daneshtalab, M. (1999). Bioorg. Med. Chem. 7, 1933-1940.]); Huang et al. (2005[Huang, L., Yuon, X., Yu, D., Lee, K. H. & Chin, H. C. (2005). Virology, 332, 623-628.]); Elinos-Baez et al. (2005[Elinos-Baez, C. M., Leon, F. & Santos, E. (2005). Cell Biol. Int. 29, 703-708.]). For the synthesis of the title compound, see: Ali & Ilyas (1986[Ali, S. M. & Ilyas, M. (1986). J. Org. Chem. 51, 5415-5417.]).

[Scheme 1]

Experimental

Crystal data

  • C12H10I2O4

  • Mr = 472.00

  • Monoclinic, P 21 /c

  • a = 10.8681 (2) Å

  • b = 9.1179 (2) Å

  • c = 17.2315 (3) Å

  • β = 125.395 (1)°

  • V = 1391.95 (5) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 4.52 mm−1

  • T = 293 K

  • 0.30 × 0.24 × 0.16 mm
Data collection

  • Bruker APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2003[Sheldrick, G. M. (2003). SADABS. University of Göttingen, Germany.]) Tmin = 0.396, Tmax = 0.485

  • 27048 measured reflections

  • 3928 independent reflections

  • 3453 reflections with I > 2σ(I)

  • Rint = 0.022
Refinement

  • R[F2 > 2σ(F2)] = 0.023

  • wR(F2) = 0.055

  • S = 1.06

  • 3928 reflections

  • 166 parameters

  • H-atom parameters constrained

  • Δρmax = 0.71 e Å−3

  • Δρmin = −0.96 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
C3—H3⋯O2i 0.93 2.53 3.460 (3) 175
Symmetry code: (i) -x, -y, -z.

Data collection: APEX2 (Bruker, 2003[Bruker (2003). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2003[Bruker (2003). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810011360/bt5225sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810011360/bt5225Isup2.hkl

checkCIF report


Comment top

Coumarin is the simplest member of the group of oxygen heterocyclics called benzo-2-pyrone. Coumarins are an important class of compounds due to their presence in natural products as well as their medicinal applications such as anti-inflammatory (Lin et al., 2006), anti-viral (Massimo et al., 2003), antioxidant (Tyagi et al., 2003), antibacterial (Nawrot-Modranka et al., 2006), antifungal (Sardari et al., 1999), anti-HIV (Huang et al., 2005) and as anti-carcinogenic (Elinos-Baez et al., 2005). Besides the wide spectrum of biological applications of coumarin and its derivatives, the chemical literature also embodies their applications as cosmetics, optical brightening agents, and laser dyes. A recent report has revealed the anion sensing ability of some coumarin derivatives. Among various coumarin derivatives, recent pharmacological evaluation of iodocoumarins as cannabinoid receptor antagonists and inverse agonists has been done. Iodocoumarins such as 8-iodo-7-hydroxycoumarin exhibited moderate activity and 8-iodo-5,7-dihydroxycoumarin displayed good antimicrobial properties with MIC values <100 µg/ml. Also, iodocoumarins had been successfully used for the optimization of reaction conditions and kinetic studies in high throughput format. Because of the biological and pharmaceutical importance of iodocoumarins, several protocols for the synthesis have been reported.

In the light of the mentioned above we planned to synthesize iodocoumarins by reaction of 5,7-dimethoxy-4-methylcoumarin with iodine in basic media (Ali & Ilyas, 1986).

In the molecule of the title compound (Fig. 1), the best plane through the aromatic ring shows an r.m.s. deviation of 0.0154 Å; the O1—C2—C3—C4—C10—C9 ring shows a slightly larger deviation from planarity, with an r.m.s. deviation of 0.0189 Å. The angle between these two planes is 4.96 (11)°.

The C2 atom of the carbonyl group has a distorted trigonal geometry with O2—C2—O1 [116.6 (2)°] and O2—C2—C3 [126.5 (2)°] deviating significantly from the ideal sp2 value of 120°.

The methoxy groups are considerably twisted with respect to the plane of the aromatic ring as indicated by the torsion angles C12—O3—C5—C6 [-85.9 (3)°] and C13—O4—C7—C6 [90.7 (3)°]. The iodine atoms are almost in the plane of the benzene ring and the methyl group is slightly out of the pyrone ring plane.

The molecules are linked across an inversion centre by one weak hydrogen bond of the C—H···O type (Fig. 2, Table 2).

Related literature top

For the medicinal applications of coumarin derivatives, see: Lin et al. (2006); Massimo et al. (2003); Tyagi et al. (2003); Nawrot-Modranka et al. (2006); Sardari et al. (1999); Huang et al. (2005); Elinos-Baez et al. (2005). For the synthesis of the title compound, see: Ali & Ilyas (1986).

Experimental top

To a stirred solution of 5,7-dimethoxy-4-methylcoumarin (2.20 g, 10 mmol) in 15-20 ml of methanol containing 8.2 g KOH was dropwise added to a solution of I2 (2.56 g, 10 mmol) over a period of 30 min and stirred at room temperature for about 2 hours. The reaction mixture was poured into water and residual iodine was removed by washing with sodium thiosulphate. On treatment with sodium thiosulphate we obtained a precipitate which was filtered and crystallized with CHCl3—MeOH as white crystals (300 mg, m.p. 490 K).

Refinement top

All H atoms were located in a difference Fourier synthesis, placed in calculated positions and refined as riding on their parent atoms, using SHELXL97 (Sheldrick, 2008) defaults.

Computing details top

Data collection: APEX2 (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A plot of the title compound. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. A packing diagram for the title compound, viewed down the a axis, with the hydrogen bonds depicted by dashed lines.
6,8-diiodo-5,7-dimethoxy-4-methyl-2H-chromen-2-one top
Crystal data top
C12H10I2O4F(000) = 880
Mr = 472.00Dx = 2.252 Mg m−3
Monoclinic, P21/cMelting point: 490 K
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 10.8681 (2) ÅCell parameters from 7934 reflections
b = 9.1179 (2) Åθ = 2.4–29.5°
c = 17.2315 (3) ŵ = 4.52 mm−1
β = 125.395 (1)°T = 293 K
V = 1391.95 (5) Å3Irregular block, pale yellow
Z = 40.30 × 0.24 × 0.16 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer		3928 independent reflections
Radiation source: fine-focus sealed tube3453 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.022
ϕ and ω scansθmax = 29.7°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)		h = −14→15
Tmin = 0.396, Tmax = 0.485k = −12→12
27048 measured reflectionsl = −24→23
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.023Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.055H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0226P)2 + 1.1738P]
where P = (Fo2 + 2Fc2)/3
3928 reflections(Δ/σ)max = 0.001
166 parametersΔρmax = 0.71 e Å−3
0 restraintsΔρmin = −0.96 e Å−3
Crystal data top
C12H10I2O4V = 1391.95 (5) Å3
Mr = 472.00Z = 4
Monoclinic, P21/cMo Kα radiation
a = 10.8681 (2) ŵ = 4.52 mm−1
b = 9.1179 (2) ÅT = 293 K
c = 17.2315 (3) Å0.30 × 0.24 × 0.16 mm
β = 125.395 (1)°
Data collection top
Bruker APEXII CCD area-detector
diffractometer		3928 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)		3453 reflections with I > 2σ(I)
Tmin = 0.396, Tmax = 0.485Rint = 0.022
27048 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0230 restraints
wR(F2) = 0.055H-atom parameters constrained
S = 1.06Δρmax = 0.71 e Å−3
3928 reflectionsΔρmin = −0.96 e Å−3
166 parameters
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.

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 (Å2) top
xyzUiso*/Ueq
I10.51053 (2)0.82363 (2)0.156895 (15)0.05749 (7)
I20.11277 (2)0.593603 (19)0.266073 (13)0.04546 (6)
O10.06827 (19)0.35475 (17)0.12276 (12)0.0353 (3)
O2−0.0507 (2)0.1432 (2)0.07590 (17)0.0548 (5)
O30.39384 (18)0.53122 (19)0.03873 (12)0.0383 (4)
O40.3379 (2)0.79647 (18)0.25451 (12)0.0434 (4)
C80.1966 (3)0.5766 (2)0.18397 (16)0.0317 (4)
C70.2959 (3)0.6823 (2)0.19268 (16)0.0337 (5)
C60.3586 (3)0.6668 (2)0.14197 (17)0.0352 (5)
C50.3273 (2)0.5453 (3)0.08510 (15)0.0318 (4)
C100.2315 (2)0.4324 (2)0.07795 (15)0.0297 (4)
C90.1647 (2)0.4549 (2)0.12598 (15)0.0294 (4)
C40.2056 (3)0.2920 (2)0.03026 (16)0.0352 (5)
C30.1095 (3)0.1972 (3)0.02911 (18)0.0395 (5)
H30.09050.1087−0.00280.047*
C20.0351 (3)0.2248 (3)0.07400 (18)0.0379 (5)
C130.2462 (4)0.9256 (3)0.2126 (2)0.0621 (8)
H13A0.23930.95130.15620.093*
H13B0.29111.00510.25730.093*
H13C0.14700.90660.19640.093*
C120.3139 (3)0.6047 (3)−0.05204 (19)0.0497 (6)
H12A0.21530.5623−0.09360.075*
H12B0.36870.5937−0.07970.075*
H12C0.30440.7070−0.04330.075*
C110.2873 (4)0.2436 (3)−0.0117 (2)0.0582 (8)
H11A0.26070.1440−0.03310.087*
H11B0.39420.25020.03570.087*
H11C0.25920.3057−0.06460.087*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.05881 (12)0.05243 (11)0.06135 (13)−0.02587 (9)0.03486 (10)−0.01030 (8)
I20.05746 (11)0.04523 (10)0.04782 (10)−0.00537 (7)0.03859 (9)−0.01056 (7)
O10.0400 (9)0.0303 (7)0.0438 (9)−0.0055 (6)0.0290 (8)−0.0069 (7)
O20.0650 (13)0.0391 (9)0.0823 (15)−0.0165 (9)0.0552 (12)−0.0145 (10)
O30.0370 (8)0.0458 (9)0.0384 (9)0.0023 (7)0.0255 (8)0.0035 (7)
O40.0572 (11)0.0325 (8)0.0355 (9)−0.0062 (8)0.0239 (8)−0.0092 (7)
C80.0355 (11)0.0304 (10)0.0307 (10)0.0031 (8)0.0200 (9)−0.0015 (8)
C70.0380 (12)0.0277 (10)0.0286 (10)−0.0006 (8)0.0154 (9)−0.0023 (8)
C60.0355 (11)0.0325 (11)0.0330 (11)−0.0057 (9)0.0172 (10)0.0007 (9)
C50.0299 (10)0.0357 (11)0.0291 (10)0.0019 (8)0.0167 (9)0.0032 (8)
C100.0307 (10)0.0294 (10)0.0271 (10)0.0008 (8)0.0157 (9)−0.0008 (8)
C90.0293 (10)0.0280 (9)0.0296 (10)0.0003 (8)0.0162 (9)−0.0005 (8)
C40.0400 (12)0.0334 (11)0.0338 (11)0.0017 (9)0.0224 (10)−0.0036 (9)
C30.0477 (14)0.0299 (11)0.0453 (13)−0.0041 (10)0.0294 (12)−0.0077 (9)
C20.0409 (12)0.0290 (10)0.0453 (13)−0.0031 (9)0.0257 (11)−0.0049 (9)
C130.093 (2)0.0340 (13)0.0625 (19)0.0072 (15)0.0471 (19)−0.0025 (12)
C120.0480 (15)0.0696 (18)0.0379 (13)0.0039 (13)0.0285 (12)0.0077 (12)
C110.078 (2)0.0493 (16)0.077 (2)−0.0089 (15)0.0618 (19)−0.0206 (15)
Geometric parameters (Å, º) top
I1—C62.084 (2)C10—C41.458 (3)
I2—C82.085 (2)C4—C31.347 (3)
O1—C91.367 (3)C4—C111.500 (3)
O1—C21.375 (3)C3—C21.428 (3)
O2—C21.208 (3)C3—H30.9300
O3—C51.359 (3)C13—H13A0.9600
O3—C121.441 (3)C13—H13B0.9600
O4—C71.365 (3)C13—H13C0.9600
O4—C131.438 (3)C12—H12A0.9600
C8—C71.389 (3)C12—H12B0.9600
C8—C91.396 (3)C12—H12C0.9600
C7—C61.392 (3)C11—H11A0.9600
C6—C51.385 (3)C11—H11B0.9600
C5—C101.418 (3)C11—H11C0.9600
C10—C91.397 (3)
C9—O1—C2121.60 (18)C4—C3—C2123.8 (2)
C5—O3—C12113.74 (18)C4—C3—H3118.1
C7—O4—C13114.3 (2)C2—C3—H3118.1
C7—C8—C9118.9 (2)O2—C2—O1116.6 (2)
C7—C8—I2119.53 (16)O2—C2—C3126.5 (2)
C9—C8—I2121.34 (16)O1—C2—C3116.9 (2)
O4—C7—C8120.0 (2)O4—C13—H13A109.5
O4—C7—C6120.2 (2)O4—C13—H13B109.5
C8—C7—C6119.6 (2)H13A—C13—H13B109.5
C5—C6—C7121.1 (2)O4—C13—H13C109.5
C5—C6—I1119.26 (17)H13A—C13—H13C109.5
C7—C6—I1119.58 (16)H13B—C13—H13C109.5
O3—C5—C6119.7 (2)O3—C12—H12A109.5
O3—C5—C10119.6 (2)O3—C12—H12B109.5
C6—C5—C10120.6 (2)H12A—C12—H12B109.5
C9—C10—C5116.74 (19)O3—C12—H12C109.5
C9—C10—C4117.8 (2)H12A—C12—H12C109.5
C5—C10—C4125.4 (2)H12B—C12—H12C109.5
O1—C9—C10121.85 (19)C4—C11—H11A109.5
O1—C9—C8115.25 (19)C4—C11—H11B109.5
C10—C9—C8122.8 (2)H11A—C11—H11B109.5
C3—C4—C10117.8 (2)C4—C11—H11C109.5
C3—C4—C11118.3 (2)H11A—C11—H11C109.5
C10—C4—C11123.7 (2)H11B—C11—H11C109.5
C13—O4—C7—C8−92.8 (3)C2—O1—C9—C101.7 (3)
C13—O4—C7—C690.7 (3)C2—O1—C9—C8−175.3 (2)
C9—C8—C7—O4−175.0 (2)C5—C10—C9—O1178.85 (19)
I2—C8—C7—O4−0.1 (3)C4—C10—C9—O1−5.2 (3)
C9—C8—C7—C61.5 (3)C5—C10—C9—C8−4.3 (3)
I2—C8—C7—C6176.40 (17)C4—C10—C9—C8171.7 (2)
O4—C7—C6—C5174.5 (2)C7—C8—C9—O1178.8 (2)
C8—C7—C6—C5−2.0 (3)I2—C8—C9—O14.0 (3)
O4—C7—C6—I1−2.4 (3)C7—C8—C9—C101.7 (3)
C8—C7—C6—I1−178.96 (17)I2—C8—C9—C10−173.05 (16)
C12—O3—C5—C6−85.9 (3)C9—C10—C4—C35.1 (3)
C12—O3—C5—C1096.7 (3)C5—C10—C4—C3−179.3 (2)
C7—C6—C5—O3−178.0 (2)C9—C10—C4—C11−170.8 (3)
I1—C6—C5—O3−1.1 (3)C5—C10—C4—C114.8 (4)
C7—C6—C5—C10−0.7 (3)C10—C4—C3—C2−1.8 (4)
I1—C6—C5—C10176.25 (16)C11—C4—C3—C2174.3 (3)
O3—C5—C10—C9−178.92 (19)C9—O1—C2—O2179.6 (2)
C6—C5—C10—C93.7 (3)C9—O1—C2—C31.7 (3)
O3—C5—C10—C45.4 (3)C4—C3—C2—O2−179.2 (3)
C6—C5—C10—C4−171.9 (2)C4—C3—C2—O1−1.7 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···O2i0.932.533.460 (3)175
Symmetry code: (i) −x, −y, −z.

Experimental details

Crystal data
Chemical formulaC12H10I2O4
Mr472.00
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)10.8681 (2), 9.1179 (2), 17.2315 (3)
β (°) 125.395 (1)
V (Å3)1391.95 (5)
Z4
Radiation typeMo Kα
µ (mm−1)4.52
Crystal size (mm)0.30 × 0.24 × 0.16
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2003)
Tmin, Tmax0.396, 0.485
No. of measured, independent and
observed [I > 2σ(I)] reflections		27048, 3928, 3453
Rint0.022
(sin θ/λ)max (Å−1)0.697
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.023, 0.055, 1.06
No. of reflections3928
No. of parameters166
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.71, −0.96

Computer programs: APEX2 (Bruker, 2003), SAINT (Bruker, 2003), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···O2i0.932.533.460 (3)175.1
Symmetry code: (i) −x, −y, −z.
 

Acknowledgements

This work was supported by the Fundação para a Ciência e a Tecnologia (FCT) under scholarship SFRH/BD/38387/2008.

References

First citationAli, S. M. & Ilyas, M. (1986). J. Org. Chem. 51, 5415–5417.  CrossRef CAS Web of Science Google Scholar
 First citationBruker (2003). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationElinos-Baez, C. M., Leon, F. & Santos, E. (2005). Cell Biol. Int. 29, 703–708.  Web of Science CrossRef PubMed CAS Google Scholar
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ISSN: 2056-9890
Volume 66| Part 4| April 2010| Page o988
doi:10.1107/S1600536810011360
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