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ISSN: 2056-9890

5-Fluoro-2-(4-fluoro­phen­yl)-3-methyl­sulfinyl-1-benzo­furan

aDepartment of Chemistry, Dongeui University, San 24 Kaya-dong Busanjin-gu, Busan 614-714, Republic of Korea, and bDepartment of Chemistry, Pukyong National University, 599-1 Daeyeon 3-dong, Nam-gu, Busan 608-737, Republic of Korea
*Correspondence e-mail: uklee@pknu.ac.kr

(Received 25 September 2009; accepted 28 September 2009; online 3 October 2009)

In the title compound, C15H10F2O2S, the O atom and the methyl group of the methyl­sulfinyl substituent lie on opposite sides of the plane through the benzofuran fragment. The 4-fluoro­phenyl ring is rotated out of the benzofuran plane by a dihedral angle of 28.09 (3)°. The crystal structure is stabilized by weak inter­molecular C—H⋯O and C—H⋯F hydrogen bonds.

Related literature

For the crystal structures of similar 5-fluoro-2-(4-halophen­yl)-3-methyl­sulfinyl-1-benzofuran derivatives, see: Choi et al. (2009a[Choi, H. D., Seo, P. J., Son, B. W. & Lee, U. (2009a). Acta Cryst. E65, o2084.],b[Choi, H. D., Seo, P. J., Son, B. W. & Lee, U. (2009b). Acta Cryst. E65, o2115.]). For the biological activity of benzofuran compounds, see: Howlett et al. (1999[Howlett, D. R., Perry, A. E., Godfrey, F., Swatton, J. E., Jennings, K. H., Spitzfaden, C., Wadsworth, H., Wood, S. J. & Markwell, R. E. (1999). Biochem. J. 340, 283-289.]); Twyman & Allsop (1999[Twyman, L. J. & Allsop, D. (1999). Tetrahedron Lett. 40, 9383-9384.]). For natural products with benzofuran rings, see: Akgul & Anil (2003[Akgul, Y. Y. & Anil, H. (2003). Phytochemistry, 63, 939-943.]); Soekamto et al. (2003[Soekamto, N. H., Achmad, S. A., Ghisalberti, E. L., Hakim, E. H. & Syah, Y. M. (2003). Phytochemistry, 64, 831-834.]).

[Scheme 1]

Experimental

Crystal data
  • C15H10F2O2S

  • Mr = 292.29

  • Triclinic, [P \overline 1]

  • a = 7.9275 (3) Å

  • b = 8.2069 (3) Å

  • c = 10.6822 (4) Å

  • α = 97.033 (2)°

  • β = 91.516 (2)°

  • γ = 113.533 (2)°

  • V = 630.22 (4) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.28 mm−1

  • T = 172 K

  • 0.44 × 0.23 × 0.12 mm

Data collection
  • Bruker SMART APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.888, Tmax = 0.968

  • 10883 measured reflections

  • 2900 independent reflections

  • 2661 reflections with I > 2σ(I)

  • Rint = 0.021

Refinement
  • R[F2 > 2σ(F2)] = 0.030

  • wR(F2) = 0.084

  • S = 1.06

  • 2900 reflections

  • 182 parameters

  • H-atom parameters constrained

  • Δρmax = 0.34 e Å−3

  • Δρmin = −0.30 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C14—H14⋯O2i 0.95 2.54 3.4025 (17) 151
C15—H15C⋯F2ii 0.98 2.52 3.2235 (16) 129
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) x, y, z+1.

Data collection: APEX2 (Bruker, 2009[Bruker (2009). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). SADABS, 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: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and DIAMOND (Brandenburg, 1998[Brandenburg, K. (1998). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

Benzofuran ring systems have received considerable attention in view of a wide range of biological activities (Howlett et al., 1999; Twyman & Allsop, 1999) and these compounds are ubiquitous in nature (Akgul & Anil, 2003; Soekamto et al., 2003). As a part of our ongoing studies of the effect of side chain substituents on the solid state structures of 5-fluoro-2-(4-halophenyl)-3-methylsulfinyl-1-benzofuran analogues (Choi et al., 2009a,b), we report the crystal structure of the title compound (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.004 (1) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle formed by the plane of the benzofuran ring and the 4-fluorophenyl ring is 28.09 (3)°. The crystal packing (Fig. 2) is stabilized by weak non-classical intermolecular C–H···O and C–H···F hydrogen bonds; the first between the 4-fluorophenyl H atom and the oxygen of the SO unit, with a C14–H14···O2i, the second between the methyl H atom and the fluorine of the 4-fluorophenyl ring, with a C15–H15C···F2ii, respectively (Table 1).

Related literature top

For the crystal structures of similar 5-fluoro-2-(4-halophenyl)-3-methylsulfinyl-1-benzofuran derivatives, see: Choi et al. (2009a,b). For the biological activity of benzofuran compounds, see: Howlett et al. (1999); Twyman & Allsop (1999). For natural products with benzofuran rings, see: Akgul & Anil (2003); Soekamto et al. (2003).

Experimental top

77% 3-Chloroperoxybenzoic acid (359 mg, 1.6 mmol) was added in small portions to a stirred solution of 5-fluoro-2-(4-fluorophenyl)-3-methylsulfanyl-1-benzofuran (414 mg, 1.5 mmol) in dichloromethane (30 mL) at 273 K. After being stirred at room temperature for 3h, the mixture was washed with saturated sodium bicarbonate solution and the organic layer was separated, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was purified by column chromatography (hexane-ethyl acetate, 1:1 v/v) to afford the title compound as a colorless solid [yield 80%, m.p. 437-438 K; Rf = 0.54 (hexane-ethyl acetate, 1:1 v/v)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in chloroforrm at room temperature.

Refinement top

All H atoms were geometrically positioned and refined using a riding model, with C–H = 0.95 Å for the aryl and 0.98 Å for the methyl H atoms, and with Uiso(H) = 1.2Ueq(C) for the aryl H atoms and 1.5Ueq(C) for methyl H atoms.

Structure description top

Benzofuran ring systems have received considerable attention in view of a wide range of biological activities (Howlett et al., 1999; Twyman & Allsop, 1999) and these compounds are ubiquitous in nature (Akgul & Anil, 2003; Soekamto et al., 2003). As a part of our ongoing studies of the effect of side chain substituents on the solid state structures of 5-fluoro-2-(4-halophenyl)-3-methylsulfinyl-1-benzofuran analogues (Choi et al., 2009a,b), we report the crystal structure of the title compound (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.004 (1) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle formed by the plane of the benzofuran ring and the 4-fluorophenyl ring is 28.09 (3)°. The crystal packing (Fig. 2) is stabilized by weak non-classical intermolecular C–H···O and C–H···F hydrogen bonds; the first between the 4-fluorophenyl H atom and the oxygen of the SO unit, with a C14–H14···O2i, the second between the methyl H atom and the fluorine of the 4-fluorophenyl ring, with a C15–H15C···F2ii, respectively (Table 1).

For the crystal structures of similar 5-fluoro-2-(4-halophenyl)-3-methylsulfinyl-1-benzofuran derivatives, see: Choi et al. (2009a,b). For the biological activity of benzofuran compounds, see: Howlett et al. (1999); Twyman & Allsop (1999). For natural products with benzofuran rings, see: Akgul & Anil (2003); Soekamto et al. (2003).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as a small spheres of arbitrary radius.
[Figure 2] Fig. 2. C–H···O and C–H···F hydrogen bonds (dotted lines) in the crystal structure of the title compound. [Symmetry codes: (i) - x + 1, - y + 1, - z + 1; (ii) x, y, z + 1 (iii) x, y, z - 1.]
5-Fluoro-2-(4-fluorophenyl)-3-methylsulfinyl-1-benzofuran top
Crystal data top
C15H10F2O2SZ = 2
Mr = 292.29F(000) = 300
Triclinic, P1Dx = 1.540 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.9275 (3) ÅCell parameters from 8044 reflections
b = 8.2069 (3) Åθ = 2.7–27.5°
c = 10.6822 (4) ŵ = 0.28 mm1
α = 97.033 (2)°T = 172 K
β = 91.516 (2)°Block, colorless
γ = 113.533 (2)°0.44 × 0.23 × 0.12 mm
V = 630.22 (4) Å3
Data collection top
Bruker SMART APEXII CCD
diffractometer
2900 independent reflections
Radiation source: Rotating Anode2661 reflections with I > 2σ(I)
HELIOS monochromatorRint = 0.021
Detector resolution: 10.0 pixels mm-1θmax = 27.5°, θmin = 1.9°
φ and ω scansh = 1010
Absorption correction: multi-scan
(APEX2; Bruker, 2009)
k = 1010
Tmin = 0.888, Tmax = 0.968l = 1313
10883 measured reflections
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)] = 0.030Hydrogen site location: difference Fourier map
wR(F2) = 0.084H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0414P)2 + 0.2389P]
where P = (Fo2 + 2Fc2)/3
2900 reflections(Δ/σ)max = 0.001
182 parametersΔρmax = 0.34 e Å3
0 restraintsΔρmin = 0.30 e Å3
Crystal data top
C15H10F2O2Sγ = 113.533 (2)°
Mr = 292.29V = 630.22 (4) Å3
Triclinic, P1Z = 2
a = 7.9275 (3) ÅMo Kα radiation
b = 8.2069 (3) ŵ = 0.28 mm1
c = 10.6822 (4) ÅT = 172 K
α = 97.033 (2)°0.44 × 0.23 × 0.12 mm
β = 91.516 (2)°
Data collection top
Bruker SMART APEXII CCD
diffractometer
2900 independent reflections
Absorption correction: multi-scan
(APEX2; Bruker, 2009)
2661 reflections with I > 2σ(I)
Tmin = 0.888, Tmax = 0.968Rint = 0.021
10883 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0300 restraints
wR(F2) = 0.084H-atom parameters constrained
S = 1.06Δρmax = 0.34 e Å3
2900 reflectionsΔρmin = 0.30 e Å3
182 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 > 2sigma(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
S0.17610 (4)0.19867 (4)0.58632 (3)0.02317 (10)
F10.56623 (14)0.77195 (13)0.99398 (8)0.0443 (2)
F20.04941 (15)0.22620 (14)0.02234 (8)0.0495 (3)
O10.33749 (13)0.69196 (11)0.49937 (8)0.0246 (2)
O20.31172 (14)0.17318 (13)0.67238 (10)0.0348 (2)
C10.25777 (17)0.43064 (16)0.57768 (11)0.0217 (2)
C20.35892 (17)0.57414 (16)0.67846 (12)0.0230 (2)
C30.41294 (19)0.58468 (18)0.80585 (12)0.0272 (3)
H30.38430.48070.84590.033*
C40.5103 (2)0.7554 (2)0.86950 (13)0.0312 (3)
C50.5563 (2)0.91200 (19)0.81591 (14)0.0327 (3)
H50.62391.02550.86560.039*
C60.50286 (19)0.90178 (18)0.68960 (14)0.0291 (3)
H60.53161.00620.65000.035*
C70.40540 (17)0.73123 (17)0.62445 (12)0.0239 (3)
C80.24884 (17)0.50769 (16)0.47293 (12)0.0222 (2)
C90.16701 (17)0.43530 (17)0.34357 (11)0.0223 (2)
C100.01310 (18)0.27185 (18)0.31677 (12)0.0258 (3)
H100.04250.20970.38430.031*
C110.05978 (19)0.19894 (19)0.19358 (13)0.0299 (3)
H110.16220.08610.17510.036*
C120.0214 (2)0.2958 (2)0.09877 (12)0.0316 (3)
C130.1700 (2)0.45994 (19)0.12075 (13)0.0311 (3)
H130.22030.52380.05280.037*
C140.24436 (19)0.52965 (17)0.24403 (12)0.0259 (3)
H140.34810.64170.26120.031*
C150.01622 (19)0.18188 (19)0.67642 (13)0.0295 (3)
H15A0.07410.06080.69940.044*
H15B0.10650.20560.62570.044*
H15C0.02680.27010.75350.044*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S0.02566 (18)0.01834 (16)0.02506 (16)0.00839 (13)0.00392 (12)0.00302 (11)
F10.0527 (6)0.0458 (5)0.0260 (4)0.0155 (5)0.0092 (4)0.0068 (4)
F20.0558 (6)0.0565 (6)0.0222 (4)0.0102 (5)0.0081 (4)0.0014 (4)
O10.0261 (5)0.0193 (4)0.0262 (4)0.0072 (4)0.0005 (3)0.0036 (3)
O20.0290 (5)0.0301 (5)0.0493 (6)0.0136 (4)0.0013 (4)0.0148 (4)
C10.0229 (6)0.0194 (6)0.0219 (6)0.0081 (5)0.0023 (5)0.0017 (4)
C20.0217 (6)0.0214 (6)0.0257 (6)0.0093 (5)0.0023 (5)0.0011 (5)
C30.0291 (7)0.0281 (6)0.0249 (6)0.0129 (6)0.0008 (5)0.0010 (5)
C40.0305 (7)0.0354 (7)0.0252 (6)0.0135 (6)0.0028 (5)0.0041 (5)
C50.0275 (7)0.0262 (7)0.0376 (7)0.0078 (6)0.0024 (6)0.0076 (5)
C60.0251 (7)0.0210 (6)0.0381 (7)0.0071 (5)0.0009 (5)0.0007 (5)
C70.0220 (6)0.0234 (6)0.0263 (6)0.0097 (5)0.0014 (5)0.0018 (5)
C80.0205 (6)0.0194 (6)0.0257 (6)0.0073 (5)0.0028 (5)0.0023 (4)
C90.0225 (6)0.0235 (6)0.0228 (6)0.0113 (5)0.0021 (5)0.0033 (5)
C100.0241 (6)0.0280 (6)0.0241 (6)0.0085 (5)0.0028 (5)0.0065 (5)
C110.0252 (7)0.0304 (7)0.0297 (7)0.0074 (6)0.0026 (5)0.0024 (5)
C120.0333 (7)0.0398 (8)0.0208 (6)0.0152 (6)0.0032 (5)0.0016 (5)
C130.0349 (7)0.0351 (7)0.0251 (6)0.0145 (6)0.0061 (5)0.0095 (5)
C140.0266 (6)0.0241 (6)0.0273 (6)0.0100 (5)0.0041 (5)0.0058 (5)
C150.0284 (7)0.0295 (7)0.0318 (7)0.0118 (6)0.0088 (5)0.0077 (5)
Geometric parameters (Å, º) top
S—O21.4897 (10)C6—C71.3820 (18)
S—C11.7646 (12)C6—H60.9500
S—C151.7922 (13)C8—C91.4584 (17)
F1—C41.3636 (15)C9—C101.3966 (18)
F2—C121.3565 (15)C9—C141.4011 (17)
O1—C71.3773 (15)C10—C111.3837 (18)
O1—C81.3773 (15)C10—H100.9500
C1—C81.3645 (17)C11—C121.377 (2)
C1—C21.4417 (17)C11—H110.9500
C2—C71.3946 (17)C12—C131.378 (2)
C2—C31.3977 (17)C13—C141.3835 (19)
C3—C41.3769 (19)C13—H130.9500
C3—H30.9500C14—H140.9500
C4—C51.389 (2)C15—H15A0.9800
C5—C61.386 (2)C15—H15B0.9800
C5—H50.9500C15—H15C0.9800
O2—S—C1107.26 (6)C1—C8—C9133.40 (12)
O2—S—C15106.17 (6)O1—C8—C9115.96 (10)
C1—S—C1597.08 (6)C10—C9—C14119.18 (12)
C7—O1—C8106.55 (9)C10—C9—C8121.02 (11)
C8—C1—C2107.21 (11)C14—C9—C8119.79 (12)
C8—C1—S126.69 (10)C11—C10—C9121.14 (12)
C2—C1—S125.96 (9)C11—C10—H10119.4
C7—C2—C3119.65 (12)C9—C10—H10119.4
C7—C2—C1105.04 (11)C12—C11—C10117.62 (13)
C3—C2—C1135.31 (12)C12—C11—H11121.2
C4—C3—C2115.71 (13)C10—C11—H11121.2
C4—C3—H3122.1F2—C12—C11118.17 (13)
C2—C3—H3122.1F2—C12—C13118.46 (12)
F1—C4—C3117.70 (13)C11—C12—C13123.37 (13)
F1—C4—C5117.60 (12)C12—C13—C14118.51 (12)
C3—C4—C5124.70 (13)C12—C13—H13120.7
C6—C5—C4119.67 (13)C14—C13—H13120.7
C6—C5—H5120.2C13—C14—C9120.14 (12)
C4—C5—H5120.2C13—C14—H14119.9
C7—C6—C5116.25 (13)C9—C14—H14119.9
C7—C6—H6121.9S—C15—H15A109.5
C5—C6—H6121.9S—C15—H15B109.5
O1—C7—C6125.41 (12)H15A—C15—H15B109.5
O1—C7—C2110.56 (11)S—C15—H15C109.5
C6—C7—C2124.02 (12)H15A—C15—H15C109.5
C1—C8—O1110.64 (11)H15B—C15—H15C109.5
O2—S—C1—C8141.63 (11)C1—C2—C7—C6179.46 (12)
C15—S—C1—C8108.95 (12)C2—C1—C8—O10.09 (14)
O2—S—C1—C233.41 (12)S—C1—C8—O1175.89 (9)
C15—S—C1—C276.01 (12)C2—C1—C8—C9179.81 (12)
C8—C1—C2—C70.38 (13)S—C1—C8—C94.0 (2)
S—C1—C2—C7175.46 (9)C7—O1—C8—C10.53 (13)
C8—C1—C2—C3179.48 (14)C7—O1—C8—C9179.39 (10)
S—C1—C2—C34.7 (2)C1—C8—C9—C1028.3 (2)
C7—C2—C3—C40.23 (18)O1—C8—C9—C10151.79 (11)
C1—C2—C3—C4179.61 (13)C1—C8—C9—C14151.07 (14)
C2—C3—C4—F1179.84 (11)O1—C8—C9—C1428.83 (16)
C2—C3—C4—C50.0 (2)C14—C9—C10—C112.31 (19)
F1—C4—C5—C6179.82 (12)C8—C9—C10—C11177.08 (12)
C3—C4—C5—C60.0 (2)C9—C10—C11—C121.9 (2)
C4—C5—C6—C70.2 (2)C10—C11—C12—F2179.66 (12)
C8—O1—C7—C6179.50 (12)C10—C11—C12—C130.0 (2)
C8—O1—C7—C20.78 (13)F2—C12—C13—C14178.91 (12)
C5—C6—C7—O1178.94 (12)C11—C12—C13—C141.4 (2)
C5—C6—C7—C20.4 (2)C12—C13—C14—C91.0 (2)
C3—C2—C7—O1179.17 (11)C10—C9—C14—C130.82 (19)
C1—C2—C7—O10.72 (14)C8—C9—C14—C13178.58 (11)
C3—C2—C7—C60.4 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C14—H14···O2i0.952.543.4025 (17)151
C15—H15C···F2ii0.982.523.2235 (16)129
Symmetry codes: (i) x+1, y+1, z+1; (ii) x, y, z+1.

Experimental details

Crystal data
Chemical formulaC15H10F2O2S
Mr292.29
Crystal system, space groupTriclinic, P1
Temperature (K)172
a, b, c (Å)7.9275 (3), 8.2069 (3), 10.6822 (4)
α, β, γ (°)97.033 (2), 91.516 (2), 113.533 (2)
V3)630.22 (4)
Z2
Radiation typeMo Kα
µ (mm1)0.28
Crystal size (mm)0.44 × 0.23 × 0.12
Data collection
DiffractometerBruker SMART APEXII CCD
Absorption correctionMulti-scan
(APEX2; Bruker, 2009)
Tmin, Tmax0.888, 0.968
No. of measured, independent and
observed [I > 2σ(I)] reflections
10883, 2900, 2661
Rint0.021
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.030, 0.084, 1.06
No. of reflections2900
No. of parameters182
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.34, 0.30

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C14—H14···O2i0.952.543.4025 (17)151.2
C15—H15C···F2ii0.982.523.2235 (16)128.7
Symmetry codes: (i) x+1, y+1, z+1; (ii) x, y, z+1.
 

References

First citationAkgul, Y. Y. & Anil, H. (2003). Phytochemistry, 63, 939–943.  Web of Science CrossRef PubMed CAS Google Scholar
First citationBrandenburg, K. (1998). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationBruker (2009). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationChoi, H. D., Seo, P. J., Son, B. W. & Lee, U. (2009a). Acta Cryst. E65, o2084.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationChoi, H. D., Seo, P. J., Son, B. W. & Lee, U. (2009b). Acta Cryst. E65, o2115.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationHowlett, D. R., Perry, A. E., Godfrey, F., Swatton, J. E., Jennings, K. H., Spitzfaden, C., Wadsworth, H., Wood, S. J. & Markwell, R. E. (1999). Biochem. J. 340, 283–289.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSoekamto, N. H., Achmad, S. A., Ghisalberti, E. L., Hakim, E. H. & Syah, Y. M. (2003). Phytochemistry, 64, 831–834.  Web of Science CrossRef PubMed CAS Google Scholar
First citationTwyman, L. J. & Allsop, D. (1999). Tetrahedron Lett. 40, 9383–9384.  Web of Science CrossRef CAS Google Scholar

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