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

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6-Phenyl­oxane-2,4-dione

aMund-Lagowski Department of Chemistry & Biochemistry, Bradley University, Peoria, IL 61625, USA, bDepartment of Chemistry, University of Iowa, Iowa City, IA 52242, USA, and cCB 4160, Department of Chemistry, Illinois State University, Normal, IL 61790, USA
*Correspondence e-mail: eflint@fsmail.bradley.edu

(Received 30 November 2012; accepted 4 December 2012; online 12 December 2012)

The title compound, C11H10O3, is a phenyl-subsituted dihydro­pyran­dione in which the heterocycle adopts a boat conformation with the phenyl substituent canted 72.14 (5)° relative to the mean plane of the heterocycle.

Related literature

For the crystal structure of methyl 4-methyl-3,5-dioxo-1-phenyl-2-oxaspiro­[5.5]-4-carboxyl­ate, see: Kirillov et al. (2010[Kirillov, N. F., Melekhin, V. S. & Aliev, Z. G. (2010). J. Struct. Chem, 51, 996-997.]) and of trans-5,6-diphenyl­perhydro­pyran-2,4-dione, see: de Souza et al. (2009[Souza, L. C. de, Imbroisi, D. de O., De Simone, C. A., Pereira, M. A. & Malta, V. R. S. (2009). Acta Cryst. E65, o250.]). For the synthesis, see: Andersh et al. (2008[Andersh, B., Gereg, J., Amanuel, M. & Stanley, C. (2008). Synth. Commun. 38, 482-488.]). For the biological activity of the title compound and its derivatives, see: Aguiar Amaral et al. (2005[Aguiar Amaral, P., Bergold, A. M. & Eifler-Lima, V. L. (2005). J. Pharm. Pharm. Sci. 8, 69-75.]); Souza et al. (2004[Souza, L. C., Soares de Araujo, A., Sant'Ana, A. E. G. & Oliveira Imbroisi, D. (2004). Bioorg. Med. Chem. 12, 865-869.]); Tait et al. (1997[Tait, B. D., Hagen, S., Domagala, J., Ellsworth, E. L., Gajda, C., Hamilton, H. W., Vara Prasad, J. V. N., Ferguson, D., Graham, N., Hupe, D., Nouhan, C., Tummino, P. J., Humblet, C., Lunney, E. A., Pavlovsky, A., Rubin, J., Gracheck, S. J., Baldwin, E. T., Bhat, T. N., Erickson, J. W., Gulnik, S. V. & Liu, B. (1997). J. Med. Chem. 40, 3782-3791.]); Wang et al. (1999[Wang, Y., Li, Z., Li, J., Li, S. & Zhang, S. (1999). Gaodeng Xuexiao Huaxue Xuebao, 20, 1559-1563.]). For a description of the Cambridge Structural Database, see: Allen (2002[Allen, F. H. (2002). Acta Cryst. B58, 380-388.]). A geometry check was performed using Mogul, see: Bruno et al. (2004[Bruno, I. J., Cole, J. C., Kessler, M., Luo, J., Motherwell, W. D. S., Purkis, L. H., Smith, B. R., Taylor, R., Cooper, R. I., Harris, S. E. & Orpen, A. G. (2004). J. Chem. Inf. Comput. Sci. 44, 2133-2144.]). For puckering parameters, see: Cremer & Pople (1975[Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.]).

[Scheme 1]

Experimental

Crystal data
  • C11H10O3

  • Mr = 190.19

  • Orthorhombic, P b c a

  • a = 16.9888 (6) Å

  • b = 5.4501 (2) Å

  • c = 19.7350 (8) Å

  • V = 1827.28 (12) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 100 K

  • 0.17 × 0.14 × 0.03 mm

Data collection
  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2008[Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.662, Tmax = 0.746

  • 17960 measured reflections

  • 1804 independent reflections

  • 1322 reflections with I > 2σ(I)

  • Rint = 0.071

Refinement
  • R[F2 > 2σ(F2)] = 0.047

  • wR(F2) = 0.114

  • S = 1.06

  • 1804 reflections

  • 127 parameters

  • H-atom parameters constrained

  • Δρmax = 0.29 e Å−3

  • Δρmin = −0.25 e Å−3

Data collection: APEX2 (Bruker, 2008[Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: APEX2 and SAINT (Bruker, 2008[Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007[Palatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786-790.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]) and Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]); software used to prepare material for publication: WinGX (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]), PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Comment top

The title compound has a diverse array of biological effects, including reducing sensitivity to pain (Aguiar Amaral et al., 2005) and killing mollusks (Souza et al., 2004). Derivatives of this compound have anti-fungal properties (Wang et al., 1999) and are effective HIV protease inhibitors (Tait et al., 1997).

The molecular structure (Fig. 1.) is the singular moiety in the asymmetric unit. A Mogul (Bruno et al., 2004) geometry check showed all non-H bond angles and distances to be normal. Ring puckering analysis of the dihydropyrandione ring using PLATON (Spek, 2009; Cremer & Pople, 1975) indicates Φ = 297.5 (2)° and θ = 84.76 (18)° for the O3—C1—C2—C3—C4—C5 ring. These parameters are consistent with a formal conformational assignment close to an idealized BC2,C5 boat with C2 at the bow and C5 at the stern. The plane of the phenyl ring attached to C5 may be described as a rudder canted 72.14 (5)° relative to the mean plane of the six core atoms of the heterocycle. The 106.6 (2)° C6—C5—O3 bond angle compared to the 112.8 (2)° C6—C5—C4 bond angle indicates a small steer to said rudder; however, whether it is to port or starboard depends upon which enantiomer is considered.

Based upon a CSD search (Allen, 2002), two structures containing similar lactone ring motifs have been reported in the crystallographic literature. These include the spiro compound methyl 4-methyl-3,5-dioxo-1-phenyl-2-oxaspiro[5.5]-4-carboxylate with CSD refcode IRITIN (Kirillov et al., 2010) and trans-5,6-diphenylperhydropyran-2,4-dione with CSD refcode PONVAQ (de Souza et al., 2009). In all three cases the pyran rings adopt the boat conformation.

Related literature top

For the crystal structure of methyl 4-methyl-3,5-dioxo-1-phenyl-2-oxaspiro[5.5]-4-carboxylate, see: Kirillov et al. (2010). For the crystal structure of trans-5,6-diphenylperhydropyran-2,4-dione, see: de Souza et al. (2009). For the synthesis, see: Andersh et al. (2008). For the biological activity of the title compound and its derivatives, see: Aguiar Amaral et al. (2005); Souza et al. (2004); Tait et al. (1997); Wang et al. (1999). For a description of the Cambridge Structural Database, see: Allen (2002). A geometry check was performed using Mogul, see: Bruno et al. (2004). For puckering parameters, see: Cremer & Pople (1975).

Experimental top

The title compound 6-(phenyl)-dihydro-2H-pyran-2,4-(3H)-dione, (also named 5-phenyl-3-oxo-delta-lactone), was prepared by the literature method (Andersh et al., 2008). Benzaldehyde (2 mmol), ethanol (2 ml), ethylacetoacetate (2 mmol), and potassium carbonate (4 mmol) were heated overnight under nitrogen at 318 K. The solution was diluted with ethylacetate, treated with 1 M HCl, and the combined organic layer extracts were dried, filtered, concentrated, and purified by flash chromatography.

Crystals suitable for X-Ray analysis were grown by vapor diffusion of pentane into a concentrated solution of the lactone in dichloromethane.

Refinement top

All non-H atoms were refined anisotropically. All H atoms were included in the refinement in the riding-model approximation (C–H = 0.95, 0.99, and 1.00 Å for Ar–H, CH2, and CH; Uiso(H) = 1.2Ueq(C).

Structure description top

The title compound has a diverse array of biological effects, including reducing sensitivity to pain (Aguiar Amaral et al., 2005) and killing mollusks (Souza et al., 2004). Derivatives of this compound have anti-fungal properties (Wang et al., 1999) and are effective HIV protease inhibitors (Tait et al., 1997).

The molecular structure (Fig. 1.) is the singular moiety in the asymmetric unit. A Mogul (Bruno et al., 2004) geometry check showed all non-H bond angles and distances to be normal. Ring puckering analysis of the dihydropyrandione ring using PLATON (Spek, 2009; Cremer & Pople, 1975) indicates Φ = 297.5 (2)° and θ = 84.76 (18)° for the O3—C1—C2—C3—C4—C5 ring. These parameters are consistent with a formal conformational assignment close to an idealized BC2,C5 boat with C2 at the bow and C5 at the stern. The plane of the phenyl ring attached to C5 may be described as a rudder canted 72.14 (5)° relative to the mean plane of the six core atoms of the heterocycle. The 106.6 (2)° C6—C5—O3 bond angle compared to the 112.8 (2)° C6—C5—C4 bond angle indicates a small steer to said rudder; however, whether it is to port or starboard depends upon which enantiomer is considered.

Based upon a CSD search (Allen, 2002), two structures containing similar lactone ring motifs have been reported in the crystallographic literature. These include the spiro compound methyl 4-methyl-3,5-dioxo-1-phenyl-2-oxaspiro[5.5]-4-carboxylate with CSD refcode IRITIN (Kirillov et al., 2010) and trans-5,6-diphenylperhydropyran-2,4-dione with CSD refcode PONVAQ (de Souza et al., 2009). In all three cases the pyran rings adopt the boat conformation.

For the crystal structure of methyl 4-methyl-3,5-dioxo-1-phenyl-2-oxaspiro[5.5]-4-carboxylate, see: Kirillov et al. (2010). For the crystal structure of trans-5,6-diphenylperhydropyran-2,4-dione, see: de Souza et al. (2009). For the synthesis, see: Andersh et al. (2008). For the biological activity of the title compound and its derivatives, see: Aguiar Amaral et al. (2005); Souza et al. (2004); Tait et al. (1997); Wang et al. (1999). For a description of the Cambridge Structural Database, see: Allen (2002). A geometry check was performed using Mogul, see: Bruno et al. (2004). For puckering parameters, see: Cremer & Pople (1975).

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: APEX2 and SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al., 2008); software used to prepare material for publication: WinGX (Farrugia, 2012), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. The molecular structure of the compound with the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
6-Phenyloxane-2,4-dione top
Crystal data top
C11H10O3F(000) = 800
Mr = 190.19Dx = 1.383 Mg m3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 2535 reflections
a = 16.9888 (6) Åθ = 2.4–23.5°
b = 5.4501 (2) ŵ = 0.10 mm1
c = 19.7350 (8) ÅT = 100 K
V = 1827.28 (12) Å3Prism, colourless
Z = 80.17 × 0.14 × 0.03 mm
Data collection top
Bruker APEXII CCD
diffractometer
1322 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.071
φ and ω scansθmax = 26.0°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
h = 2020
Tmin = 0.662, Tmax = 0.746k = 66
17960 measured reflectionsl = 2424
1804 independent 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)] = 0.047Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.114H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.039P)2 + 1.8272P]
where P = (Fo2 + 2Fc2)/3
1804 reflections(Δ/σ)max < 0.001
127 parametersΔρmax = 0.29 e Å3
0 restraintsΔρmin = 0.25 e Å3
Crystal data top
C11H10O3V = 1827.28 (12) Å3
Mr = 190.19Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 16.9888 (6) ŵ = 0.10 mm1
b = 5.4501 (2) ÅT = 100 K
c = 19.7350 (8) Å0.17 × 0.14 × 0.03 mm
Data collection top
Bruker APEXII CCD
diffractometer
1804 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
1322 reflections with I > 2σ(I)
Tmin = 0.662, Tmax = 0.746Rint = 0.071
17960 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0470 restraints
wR(F2) = 0.114H-atom parameters constrained
S = 1.06Δρmax = 0.29 e Å3
1804 reflectionsΔρmin = 0.25 e Å3
127 parameters
Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
C10.15992 (11)0.2655 (4)0.22819 (11)0.0198 (5)
C20.13487 (12)0.0646 (4)0.27556 (11)0.0208 (5)
H2A0.12030.13760.31980.025*
H2B0.17990.04740.28330.025*
C30.06630 (12)0.0808 (4)0.24883 (12)0.0200 (5)
C40.06699 (12)0.1241 (4)0.17377 (11)0.0203 (5)
H4A0.02220.03570.15290.024*
H4B0.05980.30150.16490.024*
C50.14301 (12)0.0391 (4)0.14093 (11)0.0197 (5)
H50.18690.14890.15570.024*
C60.13875 (12)0.0384 (4)0.06490 (11)0.0196 (5)
C70.17318 (12)0.2284 (4)0.02863 (12)0.0240 (5)
H70.20020.35540.0520.029*
C80.16830 (13)0.2336 (4)0.04141 (12)0.0289 (6)
H80.19210.3640.06590.035*
C90.12897 (13)0.0501 (4)0.07580 (12)0.0283 (5)
H90.12570.05420.12380.034*
C100.09416 (13)0.1406 (4)0.03986 (12)0.0284 (6)
H100.06720.26730.06340.034*
C110.09869 (12)0.1464 (4)0.03021 (11)0.0242 (5)
H110.07450.27630.05460.029*
O10.17979 (9)0.4702 (3)0.24675 (8)0.0240 (4)
O20.01417 (8)0.1540 (3)0.28609 (8)0.0237 (4)
O30.16073 (8)0.2144 (3)0.16170 (7)0.0211 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0139 (10)0.0164 (11)0.0290 (13)0.0004 (8)0.0010 (9)0.0005 (10)
C20.0213 (10)0.0181 (11)0.0230 (11)0.0013 (8)0.0009 (9)0.0004 (9)
C30.0190 (10)0.0102 (9)0.0307 (12)0.0038 (8)0.0010 (10)0.0024 (9)
C40.0183 (10)0.0147 (10)0.0279 (12)0.0013 (9)0.0001 (9)0.0002 (9)
C50.0193 (10)0.0125 (10)0.0274 (12)0.0011 (8)0.0004 (9)0.0019 (9)
C60.0151 (10)0.0168 (10)0.0269 (12)0.0038 (8)0.0001 (9)0.0007 (10)
C70.0221 (11)0.0184 (11)0.0314 (13)0.0003 (9)0.0002 (9)0.0002 (10)
C80.0305 (12)0.0234 (12)0.0327 (14)0.0010 (10)0.0030 (10)0.0079 (11)
C90.0332 (13)0.0285 (13)0.0232 (12)0.0066 (10)0.0002 (10)0.0006 (11)
C100.0315 (13)0.0210 (12)0.0326 (14)0.0021 (10)0.0039 (10)0.0030 (11)
C110.0258 (11)0.0179 (11)0.0289 (13)0.0008 (9)0.0017 (10)0.0029 (10)
O10.0257 (8)0.0159 (7)0.0303 (9)0.0028 (6)0.0007 (7)0.0015 (7)
O20.0230 (8)0.0158 (7)0.0324 (9)0.0014 (6)0.0062 (7)0.0014 (7)
O30.0229 (7)0.0152 (7)0.0253 (9)0.0048 (6)0.0002 (6)0.0004 (7)
Geometric parameters (Å, º) top
C1—O11.222 (3)C5—H51
C1—O31.342 (2)C6—C71.388 (3)
C1—C21.501 (3)C6—C111.395 (3)
C2—C31.505 (3)C7—C81.385 (3)
C2—H2A0.99C7—H70.95
C2—H2B0.99C8—C91.381 (3)
C3—O21.218 (2)C8—H80.95
C3—C41.500 (3)C9—C101.391 (3)
C4—C51.517 (3)C9—H90.95
C4—H4A0.99C10—C111.385 (3)
C4—H4B0.99C10—H100.95
C5—O31.472 (2)C11—H110.95
C5—C61.502 (3)
O1—C1—O3118.69 (19)C6—C5—H5109.2
O1—C1—C2123.9 (2)C4—C5—H5109.2
O3—C1—C2117.43 (18)C7—C6—C11119.4 (2)
C1—C2—C3112.66 (18)C7—C6—C5119.53 (19)
C1—C2—H2A109.1C11—C6—C5121.03 (19)
C3—C2—H2A109.1C8—C7—C6120.3 (2)
C1—C2—H2B109.1C8—C7—H7119.8
C3—C2—H2B109.1C6—C7—H7119.8
H2A—C2—H2B107.8C9—C8—C7120.3 (2)
O2—C3—C4123.38 (19)C9—C8—H8119.9
O2—C3—C2121.6 (2)C7—C8—H8119.9
C4—C3—C2115.03 (18)C8—C9—C10119.8 (2)
C3—C4—C5112.35 (17)C8—C9—H9120.1
C3—C4—H4A109.1C10—C9—H9120.1
C5—C4—H4A109.1C11—C10—C9120.2 (2)
C3—C4—H4B109.1C11—C10—H10119.9
C5—C4—H4B109.1C9—C10—H10119.9
H4A—C4—H4B107.9C10—C11—C6120.0 (2)
O3—C5—C6106.59 (17)C10—C11—H11120
O3—C5—C4109.98 (16)C6—C11—H11120
C6—C5—C4112.73 (17)C1—O3—C5117.72 (16)
O3—C5—H5109.2
O1—C1—C2—C3139.8 (2)C11—C6—C7—C80.4 (3)
O3—C1—C2—C340.6 (3)C5—C6—C7—C8178.5 (2)
C1—C2—C3—O2141.94 (19)C6—C7—C8—C90.1 (3)
C1—C2—C3—C437.3 (2)C7—C8—C9—C100.0 (3)
O2—C3—C4—C5173.43 (19)C8—C9—C10—C110.2 (3)
C2—C3—C4—C57.4 (2)C9—C10—C11—C60.5 (3)
C3—C4—C5—O350.7 (2)C7—C6—C11—C100.6 (3)
C3—C4—C5—C6169.46 (17)C5—C6—C11—C10178.68 (19)
O3—C5—C6—C7137.70 (18)O1—C1—O3—C5174.97 (17)
C4—C5—C6—C7101.5 (2)C2—C1—O3—C54.6 (3)
O3—C5—C6—C1144.2 (2)C6—C5—O3—C1173.64 (17)
C4—C5—C6—C1176.5 (2)C4—C5—O3—C151.1 (2)

Experimental details

Crystal data
Chemical formulaC11H10O3
Mr190.19
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)100
a, b, c (Å)16.9888 (6), 5.4501 (2), 19.7350 (8)
V3)1827.28 (12)
Z8
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.17 × 0.14 × 0.03
Data collection
DiffractometerBruker APEXII CCD
Absorption correctionMulti-scan
(SADABS; Bruker, 2008)
Tmin, Tmax0.662, 0.746
No. of measured, independent and
observed [I > 2σ(I)] reflections
17960, 1804, 1322
Rint0.071
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.047, 0.114, 1.06
No. of reflections1804
No. of parameters127
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.29, 0.25

Computer programs: APEX2 (Bruker, 2008), APEX2 and SAINT (Bruker, 2008), SAINT (Bruker, 2008), SUPERFLIP (Palatinus & Chapuis, 2007), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al., 2008), WinGX (Farrugia, 2012), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

 

Acknowledgements

The authors thank the NSF–CHE (grant No. 1039689) for funding the X-ray diffractometer.

References

First citationAguiar Amaral, P., Bergold, A. M. & Eifler-Lima, V. L. (2005). J. Pharm. Pharm. Sci. 8, 69–75.  PubMed Google Scholar
First citationAllen, F. H. (2002). Acta Cryst. B58, 380–388.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationAndersh, B., Gereg, J., Amanuel, M. & Stanley, C. (2008). Synth. Commun. 38, 482–488.  Web of Science CrossRef CAS Google Scholar
First citationBruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruno, I. J., Cole, J. C., Kessler, M., Luo, J., Motherwell, W. D. S., Purkis, L. H., Smith, B. R., Taylor, R., Cooper, R. I., Harris, S. E. & Orpen, A. G. (2004). J. Chem. Inf. Comput. Sci. 44, 2133–2144.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationCremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358.  CrossRef CAS Web of Science Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationKirillov, N. F., Melekhin, V. S. & Aliev, Z. G. (2010). J. Struct. Chem, 51, 996–997.  Web of Science CrossRef CAS Google Scholar
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationPalatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786–790.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSouza, L. C. de, Imbroisi, D. de O., De Simone, C. A., Pereira, M. A. & Malta, V. R. S. (2009). Acta Cryst. E65, o250.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSouza, L. C., Soares de Araujo, A., Sant'Ana, A. E. G. & Oliveira Imbroisi, D. (2004). Bioorg. Med. Chem. 12, 865–869.  Web of Science PubMed Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationTait, B. D., Hagen, S., Domagala, J., Ellsworth, E. L., Gajda, C., Hamilton, H. W., Vara Prasad, J. V. N., Ferguson, D., Graham, N., Hupe, D., Nouhan, C., Tummino, P. J., Humblet, C., Lunney, E. A., Pavlovsky, A., Rubin, J., Gracheck, S. J., Baldwin, E. T., Bhat, T. N., Erickson, J. W., Gulnik, S. V. & Liu, B. (1997). J. Med. Chem. 40, 3782–3791.  CrossRef Web of Science Google Scholar
First citationWang, Y., Li, Z., Li, J., Li, S. & Zhang, S. (1999). Gaodeng Xuexiao Huaxue Xuebao, 20, 1559–1563.  CAS Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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