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

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ISSN: 2056-9890

4-Methyl-2-oxo-2,3-di­hydro-1-benzo­pyran-7-yl benzene­sulfonate

aSchool of Chemical Engineering, Huaihai Institute of Technology, Lianyungang 222005, People's Republic of China, bCollege of Chemistry and Chemical Engineering, Liaocheng University, Shandong 252059, People's Republic of China, and cSchool of Mathematics and Science, Huaihai Institute of Technology, Lianyungang 222005, People's Republic of China
*Correspondence e-mail: yangshuping@hhit.edu.cn

(Received 30 September 2008; accepted 5 October 2008; online 9 October 2008)

The title compound, C16H12O5S, is a derivative of coumarin. The dihedral angle between the coumarin ring system and the phenyl ring is 65.9 (1)°. In the crystal structure, mol­ecules are linked by weak C—H⋯O hydrogen bonding to form molecular ribbons.

Related literature

For general background, see: Xie et al. (2001[Xie, L., Takeuchi, Y., Cosentino, L. M., McPhail, A. T. & Lee, K. H. (2001). J. Med. Chem. 44, 664-671.]); Tanitame et al. (2004[Tanitame, A., Oyamada, Y., Ofuji, K., Kyoya, Y., Suzuki, K., Ito, H., Kawasaki, M., Nagai, K., Wachi, M. & Yamagishi, J. (2004). J. Med. Chem. 47, 3693-3696.]); Shao et al. (1997[Shao, X., Ekstrand, D. H. L., Bhikhabhai, R., Kallander, C. F. R. & Gronowitz, J. S. (1997). Antivir. Chem. Chemother. 8, 149-159.]); Rendenbach-Müller et al. (1994[Rendenbach-Müller, B., Schelcker, R., Traut, M. & Weifenbach, H. (1994). Bioorg. Med. Chem. Lett. 4, 1195-1198.]); Pochet et al. (1996[Pochet, L., Doucet, C., Schynts, M., Thierry, N., Boggeto, N., Pirotte, B., Jiang, K. Y., Masereel, B., Tulio, P. D., Delarge, J. & Reboud-Ravaux, M. (1996). J. Med. Chem. 39, 2579-2585.]); Yang et al. (2007[Yang, S.-P., Han, L.-J. & Wang, D.-Q. (2007). Acta Cryst. E63, o135-o137.], 2006[Yang, S.-P., Han, L.-J., Wang, D.-Q. & Xia, H.-T. (2006). Acta Cryst. E62, o4350-o4352.]). For a related structure, see: Yang et al. (2007[Yang, S.-P., Han, L.-J. & Wang, D.-Q. (2007). Acta Cryst. E63, o135-o137.]).

[Scheme 1]

Experimental

Crystal data
  • C16H12O5S

  • Mr = 316.32

  • Orthorhombic, P b c n

  • a = 23.319 (3) Å

  • b = 9.0865 (12) Å

  • c = 13.7280 (17) Å

  • V = 2908.8 (6) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.24 mm−1

  • T = 298 (2) K

  • 0.48 × 0.35 × 0.23 mm

Data collection
  • Siemens SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.892, Tmax = 0.946

  • 11238 measured reflections

  • 2557 independent reflections

  • 1340 reflections with I > 2σ(I)

  • Rint = 0.077

Refinement
  • R[F2 > 2σ(F2)] = 0.049

  • wR(F2) = 0.164

  • S = 1.09

  • 2557 reflections

  • 200 parameters

  • H-atom parameters constrained

  • Δρmax = 0.21 e Å−3

  • Δρmin = −0.27 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C6—H6⋯O4i 0.93 2.43 3.325 (4) 163
C8—H8⋯O2ii 0.93 2.48 3.293 (5) 145
Symmetry codes: (i) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, z]; (ii) x, y-1, z.

Data collection: SMART (Siemens, 1996[Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Siemens, 1996[Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

Coumarin derivatives exhibit a wide variety of pharmacological activities including anti-HIV (Xie et al., 2001), antibacterial (Tanitame et al., 2004), antioxidant (Shao et al., 1997), antithrombotic (Rendenbach-Müller et al., 1994) and antiinflammatory (Pochet et al., 1996) activities. We have recently reported the crystal structures of some coumarin derivatives (Yang et al., 2007, 2006). As part of our study of the crystal structures of coumarin derivatives, we report here the crystal structure of the title coumarin derivative.

The molecular structure is shown in Fig. 1. The dihedral angle between the coumarin ring system and the phenyl ring is 65.9 (1)°. The terminal SO bond distances of 1.411 (3) and 1.421 (3) Å agree with 1.4207 (19) and 1.4331 (19) Å found in a related compound, 4-methyl-7-phenylsulfonamido-2H-1-benzopyran-2-one (Yang et al., 2007).

In the crystal the molecules are linked by weak C—H···O hydrogen bonding to form the ribbon structure (Table 1 and Fig. 2).

Related literature top

For general background, see: Xie et al. (2001); Tanitame et al. (2004); Shao et al. (1997); Rendenbach-Müller et al. (1994); Pochet et al. (1996); Yang et al. (2007, 2006). For a related structure, see: Yang et al. (2007).

Experimental top

To an anhydrous pyridine solution (10 ml) of 7-hydroxy-4-methyl-coumarin (1.76 g, 10 mmol), a solution of phenylsulfonyl chloride (11 mmol) was slowly added at 278–283 K with stirring for 30 min. The reaction mixture was stirred continuously for 12 h at room temperature and then poured into ice–water (200 ml). The solid obtained was filtered off, washed with water and dried at room temperature. Colorless crystals of the title compound suitable for X-ray structure analysis were obtained by evaporation of an ethanol solution over a period of one week.

Refinement top

H atoms were placed in calculated positions with C—H = 0.93 Å (aromatic) and 0.96 Å (methyl), and refined in riding mode with Uiso(H) = 1.2Ueq(C) (aromatic) and Uiso(H) = 1.5Ueq(C) (methyl).

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 2] Fig. 2. The crystal structure of the title compound, showing the formation of a hydrogen-bonded R33(18) ribbon along [010]. For clarity, H atoms not involving in H-bonding have been omitted. Dashed lines indicate hydrogen bonds [Symmetry codes: (*) 1/2 - x, 1/2 + y, z; (#) 1/2 - x, -1/2 + y, z; (&) x, 1 + y, x; ($) x, -1 + y, z].
4-Methyl-2-oxo-2,3-dihydro-1-benzopyran-7-yl benzenesulfonate top
Crystal data top
C16H12O5SDx = 1.445 Mg m3
Mr = 316.32Melting point: 493 K
Orthorhombic, PbcnMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2n 2abCell parameters from 1900 reflections
a = 23.319 (3) Åθ = 2.4–22.8°
b = 9.0865 (12) ŵ = 0.24 mm1
c = 13.7280 (17) ÅT = 298 K
V = 2908.8 (6) Å3Block, colourless
Z = 80.48 × 0.35 × 0.23 mm
F(000) = 1312
Data collection top
Siemens SMART CCD area-detector
diffractometer
2557 independent reflections
Radiation source: fine-focus sealed tube1340 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.077
ϕ and ω scansθmax = 25.0°, θmin = 1.8°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 2725
Tmin = 0.892, Tmax = 0.946k = 610
11238 measured reflectionsl = 1615
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)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.164H-atom parameters constrained
S = 1.09 w = 1/[σ2(Fo2) + (0.0635P)2 + 1.4P]
where P = (Fo2 + 2Fc2)/3
2557 reflections(Δ/σ)max < 0.001
200 parametersΔρmax = 0.21 e Å3
0 restraintsΔρmin = 0.27 e Å3
Crystal data top
C16H12O5SV = 2908.8 (6) Å3
Mr = 316.32Z = 8
Orthorhombic, PbcnMo Kα radiation
a = 23.319 (3) ŵ = 0.24 mm1
b = 9.0865 (12) ÅT = 298 K
c = 13.7280 (17) Å0.48 × 0.35 × 0.23 mm
Data collection top
Siemens SMART CCD area-detector
diffractometer
2557 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1340 reflections with I > 2σ(I)
Tmin = 0.892, Tmax = 0.946Rint = 0.077
11238 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.164H-atom parameters constrained
S = 1.09Δρmax = 0.21 e Å3
2557 reflectionsΔρmin = 0.27 e Å3
200 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
O10.06623 (10)0.5712 (3)0.1179 (2)0.0475 (7)
O20.01987 (13)0.7814 (3)0.1253 (2)0.0753 (10)
O30.17597 (10)0.1409 (3)0.1092 (2)0.0554 (8)
O40.25437 (12)0.0001 (4)0.0562 (3)0.0813 (11)
O50.15694 (13)0.0921 (3)0.0244 (2)0.0686 (9)
S10.19688 (4)0.02586 (12)0.02911 (9)0.0554 (4)
C10.01573 (17)0.6497 (5)0.1241 (3)0.0511 (11)
C20.03663 (17)0.5658 (5)0.1266 (3)0.0518 (11)
H20.07120.61680.12970.062*
C30.03837 (15)0.4190 (4)0.1249 (3)0.0443 (10)
C40.01530 (14)0.3395 (4)0.1195 (3)0.0402 (9)
C50.06587 (16)0.4202 (4)0.1156 (3)0.0397 (9)
C60.11874 (15)0.3532 (4)0.1088 (3)0.0430 (10)
H60.15210.40880.10470.052*
C70.12071 (15)0.2032 (4)0.1081 (3)0.0431 (10)
C80.07195 (17)0.1177 (4)0.1123 (3)0.0529 (11)
H80.07430.01550.11160.063*
C90.01984 (17)0.1871 (4)0.1176 (3)0.0514 (11)
H90.01340.13060.11990.062*
C100.09430 (15)0.3386 (5)0.1251 (3)0.0669 (13)
H10A0.12510.40790.13170.100*
H10B0.09510.27080.17870.100*
H10C0.09850.28550.06510.100*
C110.19416 (16)0.1231 (4)0.0797 (3)0.0444 (10)
C120.24038 (18)0.2080 (5)0.1072 (4)0.0699 (14)
H120.27210.21630.06650.084*
C130.2393 (3)0.2794 (6)0.1940 (5)0.0937 (18)
H130.27050.33630.21310.112*
C140.1923 (3)0.2683 (6)0.2538 (4)0.0906 (18)
H140.19190.31750.31320.109*
C150.1467 (2)0.1859 (6)0.2267 (4)0.0723 (14)
H150.11490.17950.26750.087*
C160.14680 (18)0.1116 (5)0.1394 (3)0.0583 (12)
H160.11550.05470.12090.070*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0504 (16)0.0403 (16)0.0519 (19)0.0075 (12)0.0003 (14)0.0038 (13)
O20.089 (2)0.0449 (19)0.093 (3)0.0008 (16)0.0127 (19)0.0033 (18)
O30.0567 (16)0.0623 (18)0.0473 (19)0.0100 (14)0.0067 (14)0.0124 (15)
O40.0632 (18)0.099 (3)0.082 (2)0.0411 (17)0.0239 (17)0.0130 (19)
O50.084 (2)0.0457 (17)0.076 (2)0.0071 (15)0.0033 (18)0.0047 (16)
S10.0583 (7)0.0514 (6)0.0566 (8)0.0129 (5)0.0072 (6)0.0057 (6)
C10.063 (3)0.050 (3)0.041 (3)0.003 (2)0.005 (2)0.003 (2)
C20.050 (2)0.067 (3)0.039 (3)0.007 (2)0.003 (2)0.007 (2)
C30.045 (2)0.056 (3)0.032 (2)0.0075 (19)0.0005 (18)0.008 (2)
C40.045 (2)0.045 (2)0.030 (2)0.0130 (18)0.0001 (18)0.0077 (18)
C50.050 (2)0.037 (2)0.031 (2)0.0074 (18)0.0024 (19)0.0035 (17)
C60.045 (2)0.045 (2)0.039 (2)0.0116 (18)0.0002 (18)0.0040 (19)
C70.050 (2)0.045 (2)0.034 (2)0.0005 (19)0.0018 (19)0.0047 (19)
C80.065 (3)0.037 (2)0.057 (3)0.007 (2)0.003 (2)0.003 (2)
C90.053 (3)0.044 (2)0.057 (3)0.018 (2)0.003 (2)0.006 (2)
C100.047 (2)0.083 (3)0.071 (4)0.016 (2)0.003 (2)0.011 (3)
C110.043 (2)0.043 (2)0.047 (3)0.0069 (19)0.001 (2)0.009 (2)
C120.061 (3)0.083 (3)0.066 (4)0.014 (3)0.003 (3)0.018 (3)
C130.113 (5)0.099 (4)0.069 (4)0.029 (4)0.031 (4)0.004 (4)
C140.146 (6)0.071 (4)0.055 (4)0.016 (4)0.016 (4)0.002 (3)
C150.090 (4)0.073 (3)0.055 (4)0.022 (3)0.015 (3)0.007 (3)
C160.054 (3)0.058 (3)0.063 (3)0.003 (2)0.004 (2)0.005 (2)
Geometric parameters (Å, º) top
O1—C51.373 (4)C7—C81.378 (5)
O1—C11.379 (4)C8—C91.371 (5)
O2—C11.201 (4)C8—H80.9300
O3—C71.407 (4)C9—H90.9300
O3—S11.594 (3)C10—H10A0.9600
O4—S11.411 (3)C10—H10B0.9600
O5—S11.421 (3)C10—H10C0.9600
S1—C111.736 (4)C11—C121.378 (5)
C1—C21.440 (5)C11—C161.379 (5)
C2—C31.334 (5)C12—C131.358 (7)
C2—H20.9300C12—H120.9300
C3—C41.447 (5)C13—C141.372 (7)
C3—C101.495 (5)C13—H130.9300
C4—C91.389 (5)C14—C151.354 (7)
C4—C51.390 (4)C14—H140.9300
C5—C61.378 (5)C15—C161.376 (6)
C6—C71.364 (5)C15—H150.9300
C6—H60.9300C16—H160.9300
C5—O1—C1120.9 (3)C9—C8—H8120.8
C7—O3—S1122.4 (2)C7—C8—H8120.8
O4—S1—O5120.6 (2)C8—C9—C4121.8 (3)
O4—S1—O3102.59 (17)C8—C9—H9119.1
O5—S1—O3109.02 (17)C4—C9—H9119.1
O4—S1—C11110.2 (2)C3—C10—H10A109.5
O5—S1—C11108.70 (19)C3—C10—H10B109.5
O3—S1—C11104.37 (16)H10A—C10—H10B109.5
O2—C1—O1116.6 (4)C3—C10—H10C109.5
O2—C1—C2126.5 (4)H10A—C10—H10C109.5
O1—C1—C2116.9 (3)H10B—C10—H10C109.5
C3—C2—C1123.7 (4)C12—C11—C16120.4 (4)
C3—C2—H2118.2C12—C11—S1119.5 (3)
C1—C2—H2118.2C16—C11—S1120.1 (3)
C2—C3—C4118.3 (3)C13—C12—C11119.5 (5)
C2—C3—C10121.0 (4)C13—C12—H12120.2
C4—C3—C10120.7 (4)C11—C12—H12120.2
C9—C4—C5117.4 (3)C12—C13—C14120.4 (5)
C9—C4—C3124.4 (3)C12—C13—H13119.8
C5—C4—C3118.2 (3)C14—C13—H13119.8
O1—C5—C6115.9 (3)C15—C14—C13120.3 (5)
O1—C5—C4122.1 (3)C15—C14—H14119.9
C6—C5—C4121.9 (3)C13—C14—H14119.9
C7—C6—C5118.2 (3)C14—C15—C16120.5 (5)
C7—C6—H6120.9C14—C15—H15119.7
C5—C6—H6120.9C16—C15—H15119.7
C6—C7—C8122.4 (3)C15—C16—C11118.9 (4)
C6—C7—O3115.6 (3)C15—C16—H16120.6
C8—C7—O3121.9 (3)C11—C16—H16120.6
C9—C8—C7118.3 (4)
C7—O3—S1—O4177.3 (3)C5—C6—C7—O3174.9 (3)
C7—O3—S1—O553.7 (3)S1—O3—C7—C6125.2 (3)
C7—O3—S1—C1162.3 (3)S1—O3—C7—C858.8 (5)
C5—O1—C1—O2179.7 (4)C6—C7—C8—C90.1 (6)
C5—O1—C1—C20.8 (5)O3—C7—C8—C9175.6 (4)
O2—C1—C2—C3179.8 (4)C7—C8—C9—C40.6 (6)
O1—C1—C2—C31.1 (6)C5—C4—C9—C80.2 (6)
C1—C2—C3—C40.4 (6)C3—C4—C9—C8179.9 (4)
C1—C2—C3—C10178.4 (4)O4—S1—C11—C1223.7 (4)
C2—C3—C4—C9179.7 (4)O5—S1—C11—C12157.9 (3)
C10—C3—C4—C92.2 (6)O3—S1—C11—C1285.8 (3)
C2—C3—C4—C50.6 (5)O4—S1—C11—C16154.3 (3)
C10—C3—C4—C5177.5 (4)O5—S1—C11—C1620.0 (4)
C1—O1—C5—C6179.6 (3)O3—S1—C11—C1696.2 (3)
C1—O1—C5—C40.1 (5)C16—C11—C12—C130.6 (6)
C9—C4—C5—O1179.5 (3)S1—C11—C12—C13177.4 (4)
C3—C4—C5—O10.8 (5)C11—C12—C13—C140.5 (8)
C9—C4—C5—C60.8 (6)C12—C13—C14—C150.0 (8)
C3—C4—C5—C6178.9 (3)C13—C14—C15—C160.4 (8)
O1—C5—C6—C7178.8 (3)C14—C15—C16—C110.3 (7)
C4—C5—C6—C71.5 (6)C12—C11—C16—C150.2 (6)
C5—C6—C7—C81.1 (6)S1—C11—C16—C15177.8 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C6—H6···O4i0.932.433.325 (4)163
C8—H8···O2ii0.932.483.293 (5)145
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x, y1, z.

Experimental details

Crystal data
Chemical formulaC16H12O5S
Mr316.32
Crystal system, space groupOrthorhombic, Pbcn
Temperature (K)298
a, b, c (Å)23.319 (3), 9.0865 (12), 13.7280 (17)
V3)2908.8 (6)
Z8
Radiation typeMo Kα
µ (mm1)0.24
Crystal size (mm)0.48 × 0.35 × 0.23
Data collection
DiffractometerSiemens SMART CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.892, 0.946
No. of measured, independent and
observed [I > 2σ(I)] reflections
11238, 2557, 1340
Rint0.077
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.049, 0.164, 1.09
No. of reflections2557
No. of parameters200
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.21, 0.27

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C6—H6···O4i0.932.433.325 (4)162.7
C8—H8···O2ii0.932.483.293 (5)145.4
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x, y1, z.
 

Acknowledgements

The authors acknowledge the financial support of the Technology Science Foundation of Huaihai Institute of Technology, China.

References

First citationPochet, L., Doucet, C., Schynts, M., Thierry, N., Boggeto, N., Pirotte, B., Jiang, K. Y., Masereel, B., Tulio, P. D., Delarge, J. & Reboud-Ravaux, M. (1996). J. Med. Chem. 39, 2579–2585.  CrossRef CAS PubMed Web of Science Google Scholar
First citationRendenbach-Müller, B., Schelcker, R., Traut, M. & Weifenbach, H. (1994). Bioorg. Med. Chem. Lett. 4, 1195–1198.  CrossRef Web of Science Google Scholar
First citationShao, X., Ekstrand, D. H. L., Bhikhabhai, R., Kallander, C. F. R. & Gronowitz, J. S. (1997). Antivir. Chem. Chemother. 8, 149–159.  CAS Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSiemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.  Google Scholar
First citationTanitame, A., Oyamada, Y., Ofuji, K., Kyoya, Y., Suzuki, K., Ito, H., Kawasaki, M., Nagai, K., Wachi, M. & Yamagishi, J. (2004). J. Med. Chem. 47, 3693–3696.  Web of Science CrossRef PubMed CAS Google Scholar
First citationXie, L., Takeuchi, Y., Cosentino, L. M., McPhail, A. T. & Lee, K. H. (2001). J. Med. Chem. 44, 664–671.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationYang, S.-P., Han, L.-J. & Wang, D.-Q. (2007). Acta Cryst. E63, o135–o137.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationYang, S.-P., Han, L.-J., Wang, D.-Q. & Xia, H.-T. (2006). Acta Cryst. E62, o4350–o4352.  Web of Science CSD CrossRef IUCr Journals Google Scholar

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