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

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ISSN: 2056-9890

8-Iodo-5,7-dimeth­­oxy-4-methyl-2H-chromen-2-one

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 7 February 2011; accepted 28 February 2011; online 5 March 2011)

In the title compound, C12H11IO4, the C and O atoms of both meth­oxy groups lie very close to the mean plane of the six C atoms of the benzene ring. The O and C atoms of the group lying closest to the I atom are 0.012 (3) and 0.022 (4) Å, respectively, out of the mean plane. For the other meth­oxy group, the corresponding distances are 0.020 (3) and 0.078 (4) Å. In the crystal, there are only very weak inter­molecular C—H⋯O hydrogen bonds and O⋯I contacts [3.080 (2) Å]. The mol­ecules are approximately parallel to (100), forming a layered structure.

Related literature

For 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.]). For a similar structure, see: Pereira Silva et al. (2010[Pereira Silva, P. S., Parveen, M., Khanam, Z., Ali, A. & Ramos Silva, M. (2010). Acta Cryst. E66, o988.]).

[Scheme 1]

Experimental

Crystal data
  • C12H11IO4

  • Mr = 346.11

  • Triclinic, [P \overline 1]

  • a = 7.1103 (7) Å

  • b = 9.5825 (10) Å

  • c = 9.9866 (9) Å

  • α = 109.645 (5)°

  • β = 94.734 (5)°

  • γ = 104.060 (5)°

  • V = 611.50 (10) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 2.62 mm−1

  • T = 293 K

  • 0.30 × 0.18 × 0.13 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 = 0.511, Tmax = 0.712

  • 17329 measured reflections

  • 2970 independent reflections

  • 2701 reflections with I > 2σ(I)

  • Rint = 0.025

Refinement
  • R[F2 > 2σ(F2)] = 0.021

  • wR(F2) = 0.090

  • S = 1.28

  • 2970 reflections

  • 157 parameters

  • H-atom parameters constrained

  • Δρmax = 0.75 e Å−3

  • Δρmin = −0.59 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C6—H6⋯O2i 0.93 2.56 3.460 (4) 163
C13—H13C⋯O2i 0.96 2.51 3.211 (5) 130
Symmetry code: (i) x, y-1, 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: Mercury (Macrae et al., 2006[Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453-457.]); software used to prepare material for publication: SHELXL97.

Supporting information


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, there are also 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 0.0059 Å; the O1—C2—C3—C4—C10—C9 ring shows a larger deviation from planarity, with an r.m.s. deviation of 0.0279 Å. The angle between these two planes is 2.85 (5)°.

The C2 atom of the carbonyl group has a distorted trigonal geometry with O2—C2—O1 [116.5 (3)°] and O2—C2—C3 [127.3 (23)°] deviating significantly from the ideal sp2 value of 120°.

The methoxy groups are almost in the same plane as the aromatic ring, as indicated by the torsion angles C12—O3—C5—C6 [1.8 (4)°] and C13—O4—C7—C6 [0.3 (4)°]. This contrasts with the geometry of 6,8-diiodo-5,7-dimethoxy-4-methylcoumarin (Pereira Silva et al., 2010), where the methoxy groups are considerably out of this plane.

The iodine atom is approximately in the plane of the benzene ring and the methyl group is only slightly out of the pyrone ring plane.

In the crystal, the molecules are linked by very weak C—H···O hydrogen bonds and O···I contacts [3.080 (2) Å.]. There are no classic hydrogen bonds. The molecules are approximately parallel to (100), forming a layered structure (Fig. 2).

Related literature top

For 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). For a similar structure, see: Pereira Silva et al. (2010).

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 h. The reaction mixture was poured into water and residual iodine was removed by washing with sodium thiosulfate. On treatment with sodium thiosulfate we obtained a precipitate which was filtered and crystallized with CHCl3—MeOH as white crystals (300 mg, m.p. 490 K). This precipitate was identified as 6,8-Diiodo-5,7-dimethoxy-4-methylcoumarin (Pereira Silva et al., 2010). The mother liquor showed the mixture of one major spot along with some minor impurity, which was removed by preparative thin layer chromatography (benzene:acetone; 3:2). The pure compound thus obtained was crystallized with CHCl3—MeOH as shining crystals of (I) (50 mg, m.p. 523 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: Mercury (Macrae et al., 2006); 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 (I), viewed down the a axis.
8-Iodo-5,7-dimethoxy-4-methyl-2H-chromen-2-one top
Crystal data top
C12H11IO4Z = 2
Mr = 346.11F(000) = 336
Triclinic, P1Dx = 1.880 Mg m3
Hall symbol: -P 1Melting point: 523 K
a = 7.1103 (7) ÅMo Kα radiation, λ = 0.71073 Å
b = 9.5825 (10) ÅCell parameters from 5373 reflections
c = 9.9866 (9) Åθ = 2.6–28.2°
α = 109.645 (5)°µ = 2.62 mm1
β = 94.734 (5)°T = 293 K
γ = 104.060 (5)°Irregular block, light pink
V = 611.50 (10) Å30.30 × 0.18 × 0.13 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer
2970 independent reflections
Radiation source: fine-focus sealed tube2701 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.025
ϕ and ω scansθmax = 28.3°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
h = 99
Tmin = 0.511, Tmax = 0.712k = 1212
17329 measured reflectionsl = 1313
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)] = 0.021Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.090H-atom parameters constrained
S = 1.28 w = 1/[σ2(Fo2) + (0.0503P)2 + 0.1088P]
where P = (Fo2 + 2Fc2)/3
2970 reflections(Δ/σ)max = 0.001
157 parametersΔρmax = 0.75 e Å3
0 restraintsΔρmin = 0.59 e Å3
Crystal data top
C12H11IO4γ = 104.060 (5)°
Mr = 346.11V = 611.50 (10) Å3
Triclinic, P1Z = 2
a = 7.1103 (7) ÅMo Kα radiation
b = 9.5825 (10) ŵ = 2.62 mm1
c = 9.9866 (9) ÅT = 293 K
α = 109.645 (5)°0.30 × 0.18 × 0.13 mm
β = 94.734 (5)°
Data collection top
Bruker APEXII CCD area-detector
diffractometer
2970 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
2701 reflections with I > 2σ(I)
Tmin = 0.511, Tmax = 0.712Rint = 0.025
17329 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0210 restraints
wR(F2) = 0.090H-atom parameters constrained
S = 1.28Δρmax = 0.75 e Å3
2970 reflectionsΔρmin = 0.59 e Å3
157 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
I10.85918 (3)0.28855 (2)0.398380 (19)0.04982 (11)
O10.7959 (3)0.3031 (2)0.0951 (2)0.0420 (4)
O20.7759 (5)0.4881 (3)0.0176 (3)0.0674 (7)
O30.6758 (4)0.2218 (2)0.2155 (2)0.0476 (5)
O40.7788 (4)0.0678 (3)0.3021 (2)0.0473 (5)
C20.7757 (5)0.3557 (4)0.0158 (4)0.0463 (7)
C30.7564 (5)0.2457 (4)0.1588 (3)0.0448 (6)
H30.75810.28080.23500.054*
C40.7360 (4)0.0940 (3)0.1890 (3)0.0378 (5)
C50.7146 (4)0.1155 (3)0.0803 (3)0.0345 (5)
C60.7277 (4)0.1539 (3)0.0418 (3)0.0357 (5)
H60.71090.25650.03170.043*
C70.7659 (4)0.0396 (3)0.1791 (3)0.0359 (5)
C80.7918 (4)0.1150 (3)0.1944 (3)0.0356 (5)
C90.7759 (4)0.1501 (3)0.0716 (3)0.0335 (5)
C100.7408 (4)0.0401 (3)0.0695 (3)0.0328 (5)
C110.7118 (5)0.0087 (4)0.3441 (3)0.0468 (7)
H11A0.72690.05320.40300.070*
H11B0.58300.08190.37420.070*
H11C0.81000.06300.35450.070*
C120.6410 (6)0.3812 (4)0.2349 (4)0.0552 (8)
H12A0.75770.39600.19320.083*
H12B0.60800.44330.33620.083*
H12C0.53400.41140.18820.083*
C130.7526 (6)0.2253 (4)0.2918 (4)0.0543 (8)
H13A0.61940.28570.24700.081*
H13B0.77900.22720.38690.081*
H13C0.84180.26770.23480.081*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.06807 (17)0.03768 (14)0.03117 (13)0.01100 (10)0.00271 (9)0.00155 (9)
O10.0595 (12)0.0256 (9)0.0397 (11)0.0125 (8)0.0081 (9)0.0105 (8)
O20.110 (2)0.0386 (13)0.0677 (17)0.0334 (14)0.0261 (16)0.0265 (13)
O30.0788 (15)0.0293 (10)0.0298 (10)0.0149 (10)0.0061 (9)0.0062 (8)
O40.0766 (14)0.0390 (11)0.0294 (10)0.0203 (10)0.0069 (9)0.0144 (9)
C20.0567 (16)0.0366 (15)0.0523 (18)0.0160 (12)0.0147 (14)0.0217 (14)
C30.0577 (16)0.0417 (16)0.0433 (16)0.0159 (13)0.0127 (13)0.0239 (13)
C40.0415 (13)0.0402 (14)0.0350 (14)0.0121 (11)0.0082 (10)0.0175 (12)
C50.0409 (12)0.0300 (12)0.0297 (13)0.0109 (10)0.0054 (10)0.0073 (10)
C60.0454 (13)0.0277 (12)0.0340 (13)0.0114 (10)0.0070 (10)0.0112 (10)
C70.0422 (13)0.0351 (13)0.0314 (13)0.0126 (10)0.0052 (10)0.0127 (11)
C80.0429 (13)0.0300 (12)0.0296 (13)0.0100 (10)0.0043 (10)0.0066 (10)
C90.0366 (12)0.0266 (12)0.0346 (13)0.0081 (9)0.0057 (10)0.0086 (10)
C100.0385 (12)0.0294 (12)0.0295 (12)0.0097 (10)0.0059 (9)0.0099 (10)
C110.0625 (17)0.0474 (17)0.0293 (14)0.0130 (14)0.0084 (12)0.0149 (13)
C120.089 (2)0.0292 (14)0.0413 (17)0.0170 (15)0.0137 (16)0.0049 (13)
C130.087 (2)0.0440 (17)0.0436 (17)0.0286 (17)0.0147 (16)0.0233 (15)
Geometric parameters (Å, º) top
I1—C82.078 (3)C6—C71.392 (4)
O1—C21.374 (4)C6—H60.9300
O1—C91.374 (3)C7—C81.401 (4)
O2—C21.198 (4)C8—C91.380 (4)
O3—C51.346 (3)C9—C101.405 (4)
O3—C121.429 (4)C11—H11A0.9600
O4—C71.345 (3)C11—H11B0.9600
O4—C131.441 (4)C11—H11C0.9600
C2—C31.433 (5)C12—H12A0.9600
C3—C41.350 (4)C12—H12B0.9600
C3—H30.9300C12—H12C0.9600
C4—C101.452 (4)C13—H13A0.9600
C4—C111.498 (4)C13—H13B0.9600
C5—C61.389 (4)C13—H13C0.9600
C5—C101.423 (4)
C2—O1—C9122.5 (2)O1—C9—C8115.4 (2)
C5—O3—C12118.9 (2)O1—C9—C10120.7 (2)
C7—O4—C13118.3 (2)C8—C9—C10123.9 (2)
O2—C2—O1116.5 (3)C9—C10—C5115.6 (2)
O2—C2—C3127.3 (3)C9—C10—C4118.2 (2)
O1—C2—C3116.3 (2)C5—C10—C4126.3 (2)
C4—C3—C2123.6 (3)C4—C11—H11A109.5
C4—C3—H3118.2C4—C11—H11B109.5
C2—C3—H3118.2H11A—C11—H11B109.5
C3—C4—C10118.2 (3)C4—C11—H11C109.5
C3—C4—C11117.9 (3)H11A—C11—H11C109.5
C10—C4—C11123.9 (3)H11B—C11—H11C109.5
O3—C5—C6122.7 (2)O3—C12—H12A109.5
O3—C5—C10115.8 (2)O3—C12—H12B109.5
C6—C5—C10121.5 (2)H12A—C12—H12B109.5
C5—C6—C7120.3 (2)O3—C12—H12C109.5
C5—C6—H6119.8H12A—C12—H12C109.5
C7—C6—H6119.8H12B—C12—H12C109.5
O4—C7—C6123.8 (2)O4—C13—H13A109.5
O4—C7—C8116.3 (2)O4—C13—H13B109.5
C6—C7—C8119.9 (2)H13A—C13—H13B109.5
C9—C8—C7118.7 (2)O4—C13—H13C109.5
C9—C8—I1120.70 (19)H13A—C13—H13C109.5
C7—C8—I1120.6 (2)H13B—C13—H13C109.5
C9—O1—C2—O2172.5 (3)C2—O1—C9—C8177.2 (3)
C9—O1—C2—C37.4 (4)C2—O1—C9—C102.5 (4)
O2—C2—C3—C4172.5 (4)C7—C8—C9—O1177.7 (2)
O1—C2—C3—C47.4 (5)I1—C8—C9—O13.7 (3)
C2—C3—C4—C102.2 (4)C7—C8—C9—C101.9 (4)
C2—C3—C4—C11178.4 (3)I1—C8—C9—C10176.7 (2)
C12—O3—C5—C61.8 (4)O1—C9—C10—C5177.5 (2)
C12—O3—C5—C10177.9 (3)C8—C9—C10—C52.1 (4)
O3—C5—C6—C7179.2 (3)O1—C9—C10—C43.0 (4)
C10—C5—C6—C70.4 (4)C8—C9—C10—C4177.3 (2)
C13—O4—C7—C60.3 (4)O3—C5—C10—C9178.3 (2)
C13—O4—C7—C8179.8 (3)C6—C5—C10—C91.3 (4)
C5—C6—C7—O4179.3 (3)O3—C5—C10—C42.2 (4)
C5—C6—C7—C80.2 (4)C6—C5—C10—C4178.1 (3)
O4—C7—C8—C9178.6 (2)C3—C4—C10—C93.1 (4)
C6—C7—C8—C90.9 (4)C11—C4—C10—C9176.3 (3)
O4—C7—C8—I12.8 (3)C3—C4—C10—C5177.5 (3)
C6—C7—C8—I1177.7 (2)C11—C4—C10—C53.1 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C6—H6···O2i0.932.563.460 (4)163
C13—H13C···O2i0.962.513.211 (5)130
Symmetry code: (i) x, y1, z.

Experimental details

Crystal data
Chemical formulaC12H11IO4
Mr346.11
Crystal system, space groupTriclinic, P1
Temperature (K)293
a, b, c (Å)7.1103 (7), 9.5825 (10), 9.9866 (9)
α, β, γ (°)109.645 (5), 94.734 (5), 104.060 (5)
V3)611.50 (10)
Z2
Radiation typeMo Kα
µ (mm1)2.62
Crystal size (mm)0.30 × 0.18 × 0.13
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2003)
Tmin, Tmax0.511, 0.712
No. of measured, independent and
observed [I > 2σ(I)] reflections
17329, 2970, 2701
Rint0.025
(sin θ/λ)max1)0.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.021, 0.090, 1.28
No. of reflections2970
No. of parameters157
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.75, 0.59

Computer programs: APEX2 (Bruker, 2003), SAINT (Bruker, 2003), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), Mercury (Macrae et al., 2006).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C6—H6···O2i0.932.563.460 (4)163
C13—H13C···O2i0.962.513.211 (5)130
Symmetry code: (i) x, y1, z.
 

Acknowledgements

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

References

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