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Acta Crystallogr Sect E Struct Rep Online. 2010 November 1; 66(Pt 11): o2799–o2800.
Published online 2010 October 13. doi:  10.1107/S1600536810040067
PMCID: PMC3009212

3-Ethyl-6-[3-(4-fluoro­phen­yl)-1H-pyrazol-4-yl]-1,2,4-triazolo[3,4-b][1,3,4]thia­diazole

Abstract

In the title compound, C14H11FN6S, the 1,2,4-triazolo[3,4-b][1,3,4]thia­diazole ring system is essentially planar [maximum deviation = 0.022 (3) Å] and is inclined at dihedral angles of 15.00 (18) and 52.82 (16)° with respect to the pyrazole and phenyl rings. In the crystal, mol­ecules are linked into two-dimensional networks parallel to (100) via inter­molecular N—H(...)N and weak C—H(...)N hydrogen bonds. The crystal packing is further consolidated by weak π–π stacking inter­actions, with a centroid–centroid distance of 3.590 (2) Å. The crystal studied was an inversion twin with a 0.37 (13):0.63 (13) domain ratio.

Related literature

For general background to and the biological activity of heterocycles bearing a triazole or 1,3,4-thia­diazole group, see: Farghaly (2004 [triangle]); Czarnocka et al. (1991 [triangle]); Unangst et al. (1992 [triangle]); Dhanya et al. (2009 [triangle]); Farghaly et al. (2006 [triangle]); Omar & Aboulwafa (1986 [triangle]). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 [triangle]). For standard bond-length data, see: Allen et al. (1987 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-o2799-scheme1.jpg

Experimental

Crystal data

  • C14H11FN6S
  • M r = 314.35
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-66-o2799-efi1.jpg
  • a = 35.053 (2) Å
  • b = 3.8463 (2) Å
  • c = 9.9482 (6) Å
  • V = 1341.26 (13) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.26 mm−1
  • T = 100 K
  • 0.64 × 0.27 × 0.09 mm

Data collection

  • Bruker SMART APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2009 [triangle]) T min = 0.852, T max = 0.978
  • 6132 measured reflections
  • 2884 independent reflections
  • 2814 reflections with I > 2σ(I)
  • R int = 0.030

Refinement

  • R[F 2 > 2σ(F 2)] = 0.055
  • wR(F 2) = 0.123
  • S = 1.21
  • 2884 reflections
  • 205 parameters
  • 1 restraint
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.45 e Å−3
  • Δρmin = −0.43 e Å−3
  • Absolute structure: Flack (1983 [triangle]), 1283 Friedel pairs
  • Flack parameter: 0.37 (13)

Data collection: APEX2 (Bruker, 2009 [triangle]); cell refinement: SAINT (Bruker, 2009 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810040067/lh5142sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810040067/lh5142Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors thank Universiti Sains Malaysia (USM) for the Research University Grant (No. 1001/PFIZIK/811160). CKQ also thanks USM for the award of a USM fellowship. AMI is thankful to Head of the Chemistry Department and the Director of the National Institute of Technology-Karnataka, India, for providing research facilities.

supplementary crystallographic information

Comment

The recent literature is enriched with progressive findings about the synthesis and pharmacological activity of fused heterocycles. Heterocycles bearing a triazole or 1,3,4-thiadiazole moiety are reported to show biological properties such as antibacterial (Farghaly, 2004), anti aggregatory agent (Czarnocka et al., 1991), anti-inflammatory (Unangst et al., 1992) and anticancer (Dhanya et al., 2009) activities. In addition, the N-bridged heterocycles derived from 1,2,4-triazoles have applications in the field of medicine, agriculture and industry (Farghaly et al., 2006). 1,3,4-Thiadiazoles exhibit broad spectrum of biological activities, possibly due to the presence of toxophoric N-C-S moiety (Omar & Aboulwafa, 1986). Keeping in view of the biological importance, the title compound was synthesized to study its crystal structure.

The title molecule (Fig. 1) consists of a fluorophenyl ring (F1/C1-C6), a pyrazole ring (N1/N2/C7/C8/C9) and a 3-ethyl-[1,2,4]triazolo[3,4-b] [1,3,4]thiadiazole moiety (S1/N3-N6/C10-C14). The [1,2,4]triazolo[3,4-b] [1,3,4]thiadiazole ring system is essentially planar (maximum deviation = 0.022 (3) Å for atom N4) and is inclined at angles of 15.00 (18) and 52.82 (16)° with respect to the pyrazole and phenyl rings. Bond lengths (Allen et al., 1987) and angles are within normal ranges.

In the solid state, (Fig. 2), the molecules are linked into two-dimensional networks parallel to (100) via intermolecular N2–H1N2···N6i, C9–H9A···N5ii and C13–H13B···N1iii hydrogen bonds (see Table 1 for symmetry codes). Short intermolecular distances [3.590 (2) Å] between symmetry-related S1/N3/N4/C10/C11 (centroid Cg1) and N4-N6/C11/C12 (centroid Cg2) rings [symmetry code: X, 1+Y, Z] indicate the existence of π–π stacking interactions.

Experimental

An equimolar mixture of 4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol (0.145 g, 0.001 mol) and 3-(4-fluorophenyl)-1H-pyrazole-4-carboxylic acid (0.207 g, 0.001 mol) was dissolved in 5 ml of dry phosphorous oxychloride. The resulted solution was further heated under reflux for 7 h. Excess phosphorous oxychloride was then distilled off and the mixture was gradually poured onto crushed ice with stirring. The mixture was allowed to stand overnight and the solid was separated. The separated solid was filtered, washed thoroughly with cold water, 20% NaHCO3 solution and recrystallised from a mixture of dioxane and ethanol. Yield: 73.4 %. M.p.: 479-481 K.

Refinement

H1N2 was located in a difference Fourier map and allowed to refined freely. The remaining H atoms were positioned geometrically and refined using a riding model with C–H = 0.93-0.97 Å and Uiso(H) = 1.2 or 1.5 Ueq(C). A rotating-group model was applied for the methyl group. The crystal studied was an inversion twin with a 0.37 (13) : 0.63 (13) domain ratio. The reported Flack parameter was obtained by TWIN/BASF procedure in SHELXL (Sheldrick, 2008).

Figures

Fig. 1.
The molecular structure of the title compound showing 50% probability displacement ellipsoids for non-H atoms and the atom-numbering scheme.
Fig. 2.
Part of the crystal structure of the title compound, viewed along the b axis. H atoms not involved in hydrogen bonds (dashed lines) have been omitted for clarity.

Crystal data

C14H11FN6SF(000) = 648
Mr = 314.35Dx = 1.557 Mg m3
Orthorhombic, Pca21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2acCell parameters from 4113 reflections
a = 35.053 (2) Åθ = 2.3–30.0°
b = 3.8463 (2) ŵ = 0.26 mm1
c = 9.9482 (6) ÅT = 100 K
V = 1341.26 (13) Å3Plate, colourless
Z = 40.64 × 0.27 × 0.09 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer2884 independent reflections
Radiation source: fine-focus sealed tube2814 reflections with I > 2σ(I)
graphiteRint = 0.030
[var phi] and ω scansθmax = 27.5°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2009)h = −45→38
Tmin = 0.852, Tmax = 0.978k = −4→4
6132 measured reflectionsl = −12→12

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.055H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.123w = 1/[σ2(Fo2) + (0.0155P)2 + 3.5431P] where P = (Fo2 + 2Fc2)/3
S = 1.21(Δ/σ)max < 0.001
2884 reflectionsΔρmax = 0.45 e Å3
205 parametersΔρmin = −0.43 e Å3
1 restraintAbsolute structure: Flack (1983), 1283 Friedel pairs
Primary atom site location: structure-invariant direct methodsFlack parameter: 0.37 (13)

Special details

Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.
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)

xyzUiso*/Ueq
S10.47232 (2)0.8682 (2)0.07220 (9)0.01492 (19)
F10.23063 (7)0.4421 (7)0.0128 (3)0.0271 (6)
N10.38932 (9)0.3394 (9)−0.2794 (3)0.0178 (7)
N20.42751 (9)0.3714 (10)−0.2988 (3)0.0180 (7)
N30.40306 (9)0.6762 (8)0.1424 (3)0.0143 (7)
N40.42034 (9)0.8422 (8)0.2497 (3)0.0136 (6)
N50.46852 (9)1.1284 (9)0.3395 (3)0.0178 (7)
N60.43819 (9)1.1004 (9)0.4319 (3)0.0162 (7)
C10.33272 (11)0.3145 (10)0.0202 (4)0.0157 (7)
H1A0.35130.22680.07750.019*
C20.29475 (10)0.3088 (9)0.0598 (4)0.0160 (7)
H2A0.28760.21480.14210.019*
C30.26802 (11)0.4463 (11)−0.0264 (4)0.0185 (8)
C40.27725 (12)0.5778 (11)−0.1507 (4)0.0207 (9)
H4A0.25840.6626−0.20790.025*
C50.31518 (12)0.5807 (12)−0.1884 (4)0.0204 (9)
H5A0.32200.6721−0.27160.024*
C60.34334 (10)0.4494 (10)−0.1041 (4)0.0133 (7)
C70.38318 (11)0.4419 (10)−0.1510 (4)0.0136 (7)
C80.41873 (10)0.5305 (9)−0.0900 (4)0.0111 (7)
C90.44590 (11)0.4807 (10)−0.1900 (4)0.0146 (8)
H9A0.47200.5171−0.18210.017*
C100.42692 (10)0.6731 (10)0.0422 (3)0.0147 (8)
C110.45625 (11)0.9692 (10)0.2316 (3)0.0118 (7)
C120.40957 (10)0.9339 (9)0.3769 (4)0.0123 (7)
C130.37264 (10)0.8435 (11)0.4415 (4)0.0153 (7)
H13A0.37100.96200.52730.018*
H13B0.37220.59540.45890.018*
C140.33739 (11)0.9399 (10)0.3566 (4)0.0166 (8)
H14A0.31470.89620.40770.025*
H14B0.33700.80170.27630.025*
H14C0.33851.18170.33310.025*
H1N20.4397 (12)0.306 (13)−0.389 (4)0.024 (13)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
S10.0157 (4)0.0175 (4)0.0115 (4)−0.0014 (4)0.0014 (4)−0.0018 (4)
F10.0180 (12)0.0346 (15)0.0287 (13)0.0023 (11)0.0020 (10)0.0012 (12)
N10.0195 (17)0.0204 (17)0.0136 (16)0.0036 (14)−0.0003 (12)−0.0017 (14)
N20.0194 (16)0.0230 (18)0.0117 (14)0.0023 (15)0.0022 (13)−0.0031 (14)
N30.0209 (16)0.0097 (16)0.0123 (15)0.0002 (13)−0.0036 (13)−0.0057 (13)
N40.0165 (15)0.0151 (15)0.0093 (13)0.0011 (13)−0.0026 (12)−0.0019 (14)
N50.0173 (16)0.0198 (18)0.0163 (16)0.0012 (14)0.0005 (13)−0.0056 (14)
N60.0165 (15)0.0197 (18)0.0124 (14)−0.0003 (14)−0.0001 (12)−0.0019 (14)
C10.0189 (18)0.0148 (18)0.0133 (16)0.0005 (15)−0.0039 (14)−0.0022 (15)
C20.0217 (17)0.0153 (18)0.0108 (17)−0.0031 (14)0.0016 (16)−0.0029 (17)
C30.0142 (18)0.021 (2)0.0204 (19)0.0006 (16)−0.0016 (16)−0.0025 (17)
C40.023 (2)0.024 (2)0.0146 (19)0.0035 (18)−0.0070 (15)−0.0009 (17)
C50.025 (2)0.021 (2)0.0151 (18)−0.0004 (18)0.0005 (16)−0.0035 (16)
C60.0158 (17)0.0099 (17)0.0142 (18)−0.0005 (14)0.0006 (14)−0.0048 (14)
C70.0198 (18)0.0101 (18)0.0108 (17)0.0018 (14)−0.0018 (14)0.0002 (15)
C80.0152 (17)0.0080 (17)0.0102 (16)0.0012 (13)−0.0007 (13)−0.0005 (14)
C90.0199 (19)0.013 (2)0.0105 (16)−0.0015 (15)−0.0011 (15)−0.0013 (14)
C100.0151 (17)0.0125 (17)0.017 (2)0.0032 (14)−0.0025 (13)−0.0007 (15)
C110.0173 (17)0.0112 (17)0.0069 (16)0.0003 (14)−0.0004 (13)−0.0031 (14)
C120.0177 (17)0.0082 (17)0.0109 (16)0.0005 (14)−0.0037 (13)−0.0009 (14)
C130.0194 (18)0.0132 (18)0.0132 (17)−0.0046 (15)0.0008 (14)0.0001 (15)
C140.0169 (18)0.0162 (19)0.0166 (18)−0.0017 (15)0.0017 (15)−0.0019 (16)

Geometric parameters (Å, °)

S1—C111.727 (3)C2—H2A0.9300
S1—C101.784 (4)C3—C41.374 (6)
F1—C31.367 (4)C4—C51.382 (6)
N1—C71.354 (5)C4—H4A0.9300
N1—N21.358 (4)C5—C61.390 (5)
N2—C91.328 (5)C5—H5A0.9300
N2—H1N21.02 (5)C6—C71.473 (5)
N3—C101.301 (5)C7—C81.427 (5)
N3—N41.383 (4)C8—C91.390 (5)
N4—C111.362 (5)C8—C101.453 (5)
N4—C121.367 (5)C9—H9A0.9300
N5—C111.309 (5)C12—C131.486 (5)
N5—N61.409 (4)C13—C141.542 (5)
N6—C121.310 (5)C13—H13A0.9700
C1—C21.388 (5)C13—H13B0.9700
C1—C61.391 (5)C14—H14A0.9600
C1—H1A0.9300C14—H14B0.9600
C2—C31.376 (5)C14—H14C0.9600
C11—S1—C1087.55 (17)N1—C7—C6117.1 (3)
C7—N1—N2105.3 (3)C8—C7—C6133.5 (3)
C9—N2—N1113.0 (3)C9—C8—C7105.1 (3)
C9—N2—H1N2126 (2)C9—C8—C10124.3 (3)
N1—N2—H1N2121 (2)C7—C8—C10130.3 (3)
C10—N3—N4108.3 (3)N2—C9—C8107.1 (3)
C11—N4—C12106.6 (3)N2—C9—H9A126.4
C11—N4—N3117.9 (3)C8—C9—H9A126.4
C12—N4—N3135.4 (3)N3—C10—C8124.7 (3)
C11—N5—N6104.5 (3)N3—C10—S1116.2 (3)
C12—N6—N5110.0 (3)C8—C10—S1119.1 (3)
C2—C1—C6121.0 (4)N5—C11—N4111.3 (3)
C2—C1—H1A119.5N5—C11—S1138.7 (3)
C6—C1—H1A119.5N4—C11—S1110.0 (3)
C3—C2—C1118.0 (4)N6—C12—N4107.5 (3)
C3—C2—H2A121.0N6—C12—C13127.0 (3)
C1—C2—H2A121.0N4—C12—C13125.5 (3)
F1—C3—C4119.1 (4)C12—C13—C14113.9 (3)
F1—C3—C2118.1 (4)C12—C13—H13A108.8
C4—C3—C2122.8 (4)C14—C13—H13A108.8
C3—C4—C5118.3 (4)C12—C13—H13B108.8
C3—C4—H4A120.9C14—C13—H13B108.8
C5—C4—H4A120.9H13A—C13—H13B107.7
C4—C5—C6121.1 (4)C13—C14—H14A109.5
C4—C5—H5A119.5C13—C14—H14B109.5
C6—C5—H5A119.5H14A—C14—H14B109.5
C5—C6—C1118.8 (3)C13—C14—H14C109.5
C5—C6—C7119.3 (3)H14A—C14—H14C109.5
C1—C6—C7121.8 (3)H14B—C14—H14C109.5
N1—C7—C8109.4 (3)
C7—N1—N2—C91.3 (5)C10—C8—C9—N2−175.5 (4)
C10—N3—N4—C111.2 (4)N4—N3—C10—C8−178.0 (3)
C10—N3—N4—C12177.3 (4)N4—N3—C10—S10.7 (4)
C11—N5—N6—C12−0.7 (4)C9—C8—C10—N3−169.9 (4)
C6—C1—C2—C3−1.2 (6)C7—C8—C10—N316.1 (6)
C1—C2—C3—F1−179.7 (3)C9—C8—C10—S111.4 (5)
C1—C2—C3—C42.1 (6)C7—C8—C10—S1−162.5 (3)
F1—C3—C4—C5179.8 (4)C11—S1—C10—N3−1.7 (3)
C2—C3—C4—C5−2.0 (6)C11—S1—C10—C8177.0 (3)
C3—C4—C5—C61.0 (6)N6—N5—C11—N4−0.1 (4)
C4—C5—C6—C1−0.2 (6)N6—N5—C11—S1−179.4 (4)
C4—C5—C6—C7177.0 (4)C12—N4—C11—N50.9 (4)
C2—C1—C6—C50.3 (6)N3—N4—C11—N5178.0 (3)
C2—C1—C6—C7−176.9 (4)C12—N4—C11—S1−179.6 (2)
N2—N1—C7—C8−1.4 (4)N3—N4—C11—S1−2.5 (4)
N2—N1—C7—C6177.2 (3)C10—S1—C11—N5−178.5 (5)
C5—C6—C7—N1−42.4 (5)C10—S1—C11—N42.2 (3)
C1—C6—C7—N1134.7 (4)N5—N6—C12—N41.3 (4)
C5—C6—C7—C8135.7 (4)N5—N6—C12—C13178.5 (4)
C1—C6—C7—C8−47.2 (6)C11—N4—C12—N6−1.3 (4)
N1—C7—C8—C91.1 (4)N3—N4—C12—N6−177.7 (4)
C6—C7—C8—C9−177.2 (4)C11—N4—C12—C13−178.6 (3)
N1—C7—C8—C10175.9 (4)N3—N4—C12—C135.0 (6)
C6—C7—C8—C10−2.4 (7)N6—C12—C13—C14131.2 (4)
N1—N2—C9—C8−0.6 (5)N4—C12—C13—C14−52.0 (5)
C7—C8—C9—N2−0.3 (4)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N2—H1N2···N6i1.03 (4)1.95 (4)2.899 (4)153 (4)
C9—H9A···N5ii0.932.503.368 (5)156
C13—H13A···N1iii0.972.493.419 (5)160

Symmetry codes: (i) x, y−1, z−1; (ii) −x+1, −y+2, z−1/2; (iii) x, y+1, z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: LH5142).

References

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