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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

N,N-Di­methyl-4-[5-(5-methyl-1-phenyl-1H-pyrazol-4-yl)-1,3,4-oxa­diazol-2-yl]aniline

aCollege of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China
*Correspondence e-mail: mosqito_001@163.com

(Received 15 November 2007; accepted 17 December 2007; online 4 January 2008)

In the mol­ecule of the title compound, C20H19N5O, the pyrazole and oxadiazole rings are not completely conjugated, the dihedral angle between them being 7.97 (6)°. The pyrazole and oxadiazole rings form dihedral angles of 42.74 (6) and 4.35 (5)° with the attached phenyl and benzene rings, respectively.

Related literature

For related literature, see: Ashton et al. (1993[Ashton, W. T., Hutchins, S. M., Greenlee, W. J., Doss, G. A., Chang, R. S. L., Lotti, V. J., Faust, K. A., Chen, T. B., Zingaro, G. J., Kivlighn, S. D. & Siegl, P. K. S. (1993). J. Med. Chem. 36, 3595-3605.]); Charles et al. (2004[Charles, Q., Huang, K. M. & Wilcoxen, D. E. (2004). Bioorg. Med. Chem. Lett. 14, 3943-3947.]); Coswami et al. (1984[Coswami, B. N., Kataky, J. C. S. & Baruash, J. N. (1984). J. Heterocycl. Chem. 21, 205-208.]); Wang et al. (2006[Wang, S.-W., Wen, L.-R. & Miao, Y.-F. (2006). Acta Cryst. E62, o3471-o3472.]).

[Scheme 1]

Experimental

Crystal data
  • C20H19N5O

  • Mr = 345.40

  • Monoclinic, P 21 /c

  • a = 17.746 (7) Å

  • b = 6.942 (3) Å

  • c = 14.474 (6) Å

  • β = 99.738 (5)°

  • V = 1757.6 (12) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 293 (2) K

  • 0.28 × 0.20 × 0.08 mm

Data collection
  • Bruker APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.976, Tmax = 0.993

  • 9198 measured reflections

  • 3096 independent reflections

  • 2212 reflections with I > 2σ(I)

  • Rint = 0.025

Refinement
  • R[F2 > 2σ(F2)] = 0.039

  • wR(F2) = 0.108

  • S = 1.04

  • 3096 reflections

  • 238 parameters

  • H-atom parameters constrained

  • Δρmax = 0.19 e Å−3

  • Δρmin = −0.19 e Å−3

Data collection: APEX2 (Bruker, 2000[Bruker (2000). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1999[Bruker (1999). SAINT and SHELXTL. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); molecular graphics: SHELXTL (Bruker, 1999[Bruker (1999). SAINT and SHELXTL. Bruker AXS Inc., Madison, Wisconsin, USA.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

In recent years, 1,3,4-oxadiazole derivatives have been extensively studied due to their broad biological activities, such as herbicidal, insecticidal and fungicidal activities (Coswami et al., 1984). Pyrazoles, as an important class of compounds in medicinal chemistry, constitute the basic framework of drugs in many pharmacological and medicinal applications (Ashton et al., 1993). Bis-heterocycles with high bioactivity have been reported in literature (Charles et al., 2004). In a continuation of our study on structure-activity relationship (Wang et al., 2006), we report here the crystal structure of the title compound (Fig.1), which was synthesized from N'-(4-(dimethylamino)benzylidene)-5-methyl-1-phenyl-1H-pyrazole-4 -carbohydrazide.

Most bond lengths and angles in the title compound are as expected for this type of compounds. The N4—C12 bond length (1.290 (2) Å) in the oxadiazole ring is shorter than the N2—C9 bond length (1.311 (2) Å) in the pyrazole ring, while the N3—N4 bond length (1.4140 (19) Å) is longer than the N1—N2 bond distance (1.3701 (18) Å). This could be ascribed to the strong electron withdrawing effect of the oxygen atom in the oxadiazole ring. In addition, because of the conjugated effect among oxygen and the two C=N bonds, the C—O bond lengths are shorter than the normal C—O single bond (1.42–1.46 Å). The pyrazole and oxadiazole rings are not completely conjugated, the dihedral angle between them being 7.97 (6)°. The dihedral angles formed by the pyrazole and oxadiazole rings with the attached phenyl and benzene rings are 42.74 (6) and 4.35 (5)° respectively.

Related literature top

For related literature, see: Ashton et al. (1993); Charles et al. (2004); Coswami et al. (1984); Wang et al. (2006).

Experimental top

A mixture of N'-(4-(dimethylamino)benzylidene)-5-methyl-1-phenyl-1H-pyrazole -4-carbohydrazide (0.694 g, 2 mmol), obtained according to a previously reported procedure (Wang et al., 2006), iodosobenzene diacetate (0.644 g, 2 mmol) and anhydrous ethanol (50 ml) was stirred in a 100 ml flask at room temperature for 2 h. The solid product formed was then filtered and washed with anhydrous ethanol. Single crystals of the title compound suitable for X-ray analysis were obtained by slow evaporation of an ethanol solution (m.p. 488 K).

Refinement top

All H atoms were placed in calculated positions, with C—H = 0.93–0.96 A%, and included in the final cycles of refinement using a riding model, with Uiso(H) = 1.2 Ueq(C) or 1.5 Ueq(C) for methyl groups.

Computing details top

Data collection: APEX2 (Bruker, 2000); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1999); software used to prepare material for publication: SHELXTL (Bruker, 1999).

Figures top
[Figure 1] Fig. 1. View of the title compound with 35% probability ellipsoid.
N,N-Dimethyl-4-[5-(5-methyl-1-phenyl-1H-pyrazol-4-yl)-1,3,4-oxadiazol- 2-yl]aniline top
Crystal data top
C20H19N5OF(000) = 728
Mr = 345.40Dx = 1.305 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2162 reflections
a = 17.746 (7) Åθ = 2.3–23.1°
b = 6.942 (3) ŵ = 0.09 mm1
c = 14.474 (6) ÅT = 293 K
β = 99.738 (5)°Plate, colourless
V = 1757.6 (12) Å30.28 × 0.20 × 0.08 mm
Z = 4
Data collection top
Bruker APEXII CCD area-detector
diffractometer
3096 independent reflections
Radiation source: fine-focus sealed tube2212 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.025
ϕ and ω scansθmax = 25.0°, θmin = 2.3°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 2120
Tmin = 0.976, Tmax = 0.993k = 78
9198 measured reflectionsl = 1517
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)] = 0.039Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.108H-atom parameters constrained
S = 1.04 w = 1/[σ2(Fo2) + (0.0598P)2 + 0.1148P]
where P = (Fo2 + 2Fc2)/3
3096 reflections(Δ/σ)max = 0.001
238 parametersΔρmax = 0.19 e Å3
0 restraintsΔρmin = 0.19 e Å3
Crystal data top
C20H19N5OV = 1757.6 (12) Å3
Mr = 345.40Z = 4
Monoclinic, P21/cMo Kα radiation
a = 17.746 (7) ŵ = 0.09 mm1
b = 6.942 (3) ÅT = 293 K
c = 14.474 (6) Å0.28 × 0.20 × 0.08 mm
β = 99.738 (5)°
Data collection top
Bruker APEXII CCD area-detector
diffractometer
3096 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
2212 reflections with I > 2σ(I)
Tmin = 0.976, Tmax = 0.993Rint = 0.025
9198 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0390 restraints
wR(F2) = 0.108H-atom parameters constrained
S = 1.04Δρmax = 0.19 e Å3
3096 reflectionsΔρmin = 0.19 e Å3
238 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
O10.23457 (6)0.46275 (15)0.97159 (7)0.0441 (3)
N10.36081 (7)0.98159 (18)0.95277 (9)0.0419 (3)
N20.35181 (8)1.0599 (2)1.03710 (9)0.0519 (4)
N30.22892 (9)0.5614 (2)1.11520 (10)0.0546 (4)
N40.18766 (9)0.3870 (2)1.09869 (10)0.0554 (4)
N50.07036 (9)0.3315 (2)0.82215 (11)0.0683 (5)
C10.46094 (10)1.2036 (2)0.92564 (13)0.0560 (5)
H10.48141.19980.98920.067*
C20.49418 (11)1.3160 (3)0.86493 (16)0.0666 (6)
H20.53751.38820.88780.080*
C30.46404 (12)1.3224 (3)0.77106 (16)0.0659 (6)
H30.48691.39840.73070.079*
C40.40026 (11)1.2166 (2)0.73698 (13)0.0560 (5)
H40.38021.21990.67330.067*
C50.36550 (9)1.1050 (2)0.79661 (11)0.0465 (4)
H50.32141.03610.77360.056*
C60.39648 (9)1.0964 (2)0.89030 (11)0.0412 (4)
C70.32987 (9)0.8024 (2)0.93957 (10)0.0400 (4)
C80.29830 (9)0.7646 (2)1.01870 (10)0.0420 (4)
C90.31435 (10)0.9277 (2)1.07553 (12)0.0516 (4)
H90.30000.94081.13410.062*
C100.33531 (11)0.6795 (3)0.85662 (12)0.0558 (5)
H10A0.29110.69980.80940.084*
H10B0.33790.54650.87500.084*
H10C0.38050.71300.83190.084*
C110.25474 (9)0.5991 (2)1.03925 (11)0.0428 (4)
C120.19272 (9)0.3352 (2)1.01439 (11)0.0427 (4)
C130.16085 (9)0.1674 (2)0.96261 (11)0.0430 (4)
C140.17535 (9)0.1234 (2)0.87380 (12)0.0471 (4)
H140.20540.20630.84500.057*
C150.14621 (9)0.0402 (3)0.82743 (12)0.0501 (4)
H150.15730.06630.76810.060*
C160.10020 (9)0.1681 (2)0.86788 (12)0.0484 (4)
C170.08488 (10)0.1211 (3)0.95697 (12)0.0539 (5)
H170.05400.20200.98560.065*
C180.11459 (10)0.0419 (3)1.00279 (12)0.0519 (4)
H180.10360.06911.06200.062*
C190.09588 (13)0.4001 (3)0.73912 (15)0.0736 (6)
H19A0.08940.30050.69240.110*
H19B0.06640.51090.71550.110*
H19C0.14890.43490.75390.110*
C200.02076 (12)0.4574 (3)0.86451 (16)0.0731 (6)
H20A0.04800.50610.92280.110*
H20B0.00470.56310.82300.110*
H20C0.02330.38660.87580.110*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0498 (6)0.0455 (6)0.0386 (6)0.0029 (5)0.0125 (5)0.0024 (5)
N10.0463 (8)0.0422 (8)0.0365 (8)0.0030 (6)0.0049 (6)0.0006 (6)
N20.0677 (9)0.0506 (8)0.0369 (8)0.0056 (7)0.0077 (7)0.0051 (6)
N30.0693 (10)0.0535 (9)0.0438 (9)0.0081 (8)0.0180 (7)0.0004 (7)
N40.0689 (10)0.0561 (9)0.0450 (9)0.0106 (8)0.0205 (7)0.0011 (7)
N50.0716 (11)0.0739 (11)0.0617 (10)0.0230 (9)0.0175 (8)0.0193 (8)
C10.0505 (10)0.0482 (10)0.0648 (12)0.0017 (8)0.0034 (9)0.0090 (9)
C20.0499 (11)0.0521 (11)0.0978 (17)0.0068 (9)0.0128 (11)0.0138 (11)
C30.0708 (14)0.0469 (11)0.0880 (16)0.0084 (10)0.0362 (12)0.0188 (10)
C40.0711 (13)0.0479 (10)0.0527 (11)0.0103 (9)0.0217 (9)0.0107 (8)
C50.0489 (10)0.0443 (9)0.0468 (10)0.0035 (8)0.0094 (8)0.0035 (8)
C60.0415 (9)0.0371 (9)0.0453 (10)0.0027 (7)0.0079 (7)0.0052 (7)
C70.0410 (9)0.0387 (9)0.0395 (9)0.0031 (7)0.0045 (7)0.0005 (7)
C80.0458 (9)0.0429 (9)0.0367 (9)0.0017 (7)0.0054 (7)0.0032 (7)
C90.0653 (11)0.0541 (11)0.0359 (9)0.0042 (9)0.0102 (8)0.0012 (8)
C100.0702 (12)0.0481 (10)0.0536 (11)0.0042 (9)0.0239 (9)0.0066 (8)
C110.0469 (9)0.0444 (9)0.0367 (9)0.0044 (7)0.0060 (7)0.0023 (7)
C120.0431 (9)0.0465 (9)0.0405 (9)0.0017 (7)0.0124 (7)0.0081 (7)
C130.0439 (9)0.0466 (9)0.0396 (9)0.0023 (7)0.0103 (7)0.0043 (7)
C140.0442 (9)0.0541 (10)0.0457 (10)0.0002 (8)0.0148 (7)0.0077 (8)
C150.0495 (10)0.0626 (11)0.0399 (10)0.0008 (9)0.0127 (8)0.0014 (8)
C160.0435 (9)0.0570 (10)0.0440 (10)0.0014 (8)0.0052 (7)0.0016 (8)
C170.0548 (10)0.0601 (11)0.0494 (11)0.0138 (9)0.0163 (8)0.0006 (9)
C180.0590 (11)0.0586 (11)0.0418 (10)0.0081 (9)0.0192 (8)0.0008 (8)
C190.0827 (14)0.0702 (13)0.0685 (14)0.0006 (11)0.0145 (11)0.0198 (11)
C200.0697 (13)0.0660 (13)0.0822 (15)0.0179 (11)0.0089 (11)0.0085 (11)
Geometric parameters (Å, º) top
O1—C111.3656 (19)C7—C101.489 (2)
O1—C121.3694 (18)C8—C91.400 (2)
N1—C71.360 (2)C8—C111.443 (2)
N1—N21.3701 (18)C9—H90.9300
N1—C61.431 (2)C10—H10A0.9600
N2—C91.311 (2)C10—H10B0.9600
N3—C111.287 (2)C10—H10C0.9600
N3—N41.4140 (19)C12—C131.447 (2)
N4—C121.290 (2)C13—C141.387 (2)
N5—C161.374 (2)C13—C181.390 (2)
N5—C191.435 (2)C14—C151.375 (2)
N5—C201.448 (2)C14—H140.9300
C1—C21.380 (3)C15—C161.400 (2)
C1—C61.388 (2)C15—H150.9300
C1—H10.9300C16—C171.401 (2)
C2—C31.374 (3)C17—C181.371 (2)
C2—H20.9300C17—H170.9300
C3—C41.369 (3)C18—H180.9300
C3—H30.9300C19—H19A0.9600
C4—C51.380 (2)C19—H19B0.9600
C4—H40.9300C19—H19C0.9600
C5—C61.376 (2)C20—H20A0.9600
C5—H50.9300C20—H20B0.9600
C7—C81.383 (2)C20—H20C0.9600
C11—O1—C12102.73 (12)C7—C10—H10C109.5
C7—N1—N2112.53 (13)H10A—C10—H10C109.5
C7—N1—C6129.20 (13)H10B—C10—H10C109.5
N2—N1—C6118.20 (13)N3—C11—O1112.53 (14)
C9—N2—N1104.12 (13)N3—C11—C8128.20 (15)
C11—N3—N4106.20 (14)O1—C11—C8119.24 (13)
C12—N4—N3106.35 (13)N4—C12—O1112.19 (14)
C16—N5—C19121.80 (16)N4—C12—C13129.10 (15)
C16—N5—C20120.45 (16)O1—C12—C13118.71 (14)
C19—N5—C20117.04 (16)C14—C13—C18117.70 (15)
C2—C1—C6118.87 (18)C14—C13—C12122.67 (15)
C2—C1—H1120.6C18—C13—C12119.63 (15)
C6—C1—H1120.6C15—C14—C13121.40 (15)
C3—C2—C1120.74 (19)C15—C14—H14119.3
C3—C2—H2119.6C13—C14—H14119.3
C1—C2—H2119.6C14—C15—C16121.18 (16)
C4—C3—C2119.91 (18)C14—C15—H15119.4
C4—C3—H3120.0C16—C15—H15119.4
C2—C3—H3120.0N5—C16—C15121.80 (16)
C3—C4—C5120.35 (18)N5—C16—C17121.12 (16)
C3—C4—H4119.8C15—C16—C17117.07 (16)
C5—C4—H4119.8C18—C17—C16121.26 (16)
C6—C5—C4119.63 (17)C18—C17—H17119.4
C6—C5—H5120.2C16—C17—H17119.4
C4—C5—H5120.2C17—C18—C13121.39 (16)
C5—C6—C1120.47 (15)C17—C18—H18119.3
C5—C6—N1120.09 (14)C13—C18—H18119.3
C1—C6—N1119.40 (15)N5—C19—H19A109.5
N1—C7—C8105.52 (13)N5—C19—H19B109.5
N1—C7—C10123.88 (14)H19A—C19—H19B109.5
C8—C7—C10130.53 (15)N5—C19—H19C109.5
C7—C8—C9105.22 (14)H19A—C19—H19C109.5
C7—C8—C11128.89 (14)H19B—C19—H19C109.5
C9—C8—C11125.83 (15)N5—C20—H20A109.5
N2—C9—C8112.60 (15)N5—C20—H20B109.5
N2—C9—H9123.7H20A—C20—H20B109.5
C8—C9—H9123.7N5—C20—H20C109.5
C7—C10—H10A109.5H20A—C20—H20C109.5
C7—C10—H10B109.5H20B—C20—H20C109.5
H10A—C10—H10B109.5
C7—N1—N2—C90.54 (17)C12—O1—C11—N30.19 (16)
C6—N1—N2—C9176.53 (13)C12—O1—C11—C8178.00 (13)
C11—N3—N4—C120.29 (18)C7—C8—C11—N3176.18 (16)
C6—C1—C2—C30.1 (3)C9—C8—C11—N37.0 (3)
C1—C2—C3—C40.1 (3)C7—C8—C11—O15.9 (2)
C2—C3—C4—C50.7 (3)C9—C8—C11—O1170.91 (15)
C3—C4—C5—C61.7 (2)N3—N4—C12—O10.18 (18)
C4—C5—C6—C12.0 (2)N3—N4—C12—C13179.99 (15)
C4—C5—C6—N1179.85 (14)C11—O1—C12—N40.01 (16)
C2—C1—C6—C51.2 (3)C11—O1—C12—C13179.84 (13)
C2—C1—C6—N1179.07 (16)N4—C12—C13—C14175.58 (17)
C7—N1—C6—C541.8 (2)O1—C12—C13—C144.6 (2)
N2—N1—C6—C5134.74 (15)N4—C12—C13—C183.4 (3)
C7—N1—C6—C1140.34 (17)O1—C12—C13—C18176.37 (14)
N2—N1—C6—C143.1 (2)C18—C13—C14—C151.1 (2)
N2—N1—C7—C80.98 (17)C12—C13—C14—C15177.95 (15)
C6—N1—C7—C8175.69 (14)C13—C14—C15—C160.5 (2)
N2—N1—C7—C10176.36 (14)C19—N5—C16—C1512.1 (3)
C6—N1—C7—C107.0 (2)C20—N5—C16—C15177.81 (17)
N1—C7—C8—C90.98 (16)C19—N5—C16—C17168.77 (18)
C10—C7—C8—C9176.12 (17)C20—N5—C16—C171.3 (3)
N1—C7—C8—C11176.38 (15)C14—C15—C16—N5179.64 (16)
C10—C7—C8—C116.5 (3)C14—C15—C16—C170.5 (2)
N1—N2—C9—C80.13 (19)N5—C16—C17—C18180.00 (17)
C7—C8—C9—N20.72 (19)C15—C16—C17—C180.8 (3)
C11—C8—C9—N2176.75 (14)C16—C17—C18—C130.2 (3)
N4—N3—C11—O10.30 (18)C14—C13—C18—C170.7 (2)
N4—N3—C11—C8177.69 (15)C12—C13—C18—C17178.34 (16)

Experimental details

Crystal data
Chemical formulaC20H19N5O
Mr345.40
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)17.746 (7), 6.942 (3), 14.474 (6)
β (°) 99.738 (5)
V3)1757.6 (12)
Z4
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.28 × 0.20 × 0.08
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.976, 0.993
No. of measured, independent and
observed [I > 2σ(I)] reflections
9198, 3096, 2212
Rint0.025
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.039, 0.108, 1.04
No. of reflections3096
No. of parameters238
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.19, 0.19

Computer programs: APEX2 (Bruker, 2000), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1999).

 

Acknowledgements

This project was supported by the National Science Found­ation of China (No. 20572057) and the Natural Science Foundation of Shandong Province (No. Y2006B11)

References

First citationAshton, W. T., Hutchins, S. M., Greenlee, W. J., Doss, G. A., Chang, R. S. L., Lotti, V. J., Faust, K. A., Chen, T. B., Zingaro, G. J., Kivlighn, S. D. & Siegl, P. K. S. (1993). J. Med. Chem. 36, 3595–3605.  CrossRef CAS PubMed Web of Science Google Scholar
First citationBruker (1999). SAINT and SHELXTL. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruker (2000). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationCharles, Q., Huang, K. M. & Wilcoxen, D. E. (2004). Bioorg. Med. Chem. Lett. 14, 3943–3947.  Web of Science PubMed Google Scholar
First citationCoswami, B. N., Kataky, J. C. S. & Baruash, J. N. (1984). J. Heterocycl. Chem. 21, 205–208.  Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.  Google Scholar
First citationWang, S.-W., Wen, L.-R. & Miao, Y.-F. (2006). Acta Cryst. E62, o3471–o3472.  Web of Science CSD CrossRef IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds