organic compounds
6-(3-Chlorophenyl)imidazo[2,1-b][1,3,4]thiadiazole
aDepartment of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India, bDepartment of Chemistry, Keene State College, 229 Main Street, Keene, NH 03435-2001, USA, and cDepartment of Studies in Chemistry, Mangalore University, Mangalagangotri 574 199, India
*Correspondence e-mail: jjasinski@keene.edu
In the title compound, C10H8ClN3S, the dihedral angle between the mean planes of the benzene and imidazo[2,1-b][1,3,4]thiadiazole rings is 6.0 (9)°. In the crystal, molecules are assembled by the formation of centrosymmetric dimers by π-stacking of the thiadiazole and benzene rings of neighboring molecules [centroid–centroid distance = 3.6938 (11) Å] along [010].
Related literature
For related imidazothiadiazole derivatives and their pharmacological potential, see: Palagiano et al. (1995). For related structures, see: Banu et al. (2011a,b); Fun et al. (2011a,b). For standard bond lengths, see Allen et al. (1987).
Experimental
Crystal data
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Data collection: CrysAlis PRO (Agilent, 2012); cell CrysAlis PRO; data reduction: CrysAlis RED (Agilent, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536812049793/im2414sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536812049793/im2414Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536812049793/im2414Isup3.cml
A solution of 1,3,4-thiadiazol-2-amine (500 mg, 4.9 mmol) and 2-bromo-1-(3-chlorophenyl)ethanone (1.1 g, 4.9 mmol) in DMF (10 mL) was placed in a microwave pyrex tube which was introduced into a Biotage Initiator-microwave reactor fitted with a rotational system. Microwave irradiation was performed for 10 minutes at 373 K, then the mixture was cooled to ambient temperature. The reaction mass was poured into ice, the precipitated solid was filtered and dried. The single crystal was grown from a solution in ethyl acetate by slow evaporation of the solvent (yield: 97%; (m.p.: 437–440 K).
All H atoms were placed in their calculated positions and then refined using the riding model with C—H lengths of 0.93Å. Isotropic displacement parameters for hydrogen atoms were set to 1.18-1.21 (CH) times Ueq of the parent atom.
Many imidazothiadiazole derivatives have been reported to possess diverse medicinal properties such as anthelmintic, antimicrobial, anti-inflammatory, antipyretic, analgesic properties and many other activities of therapeutic significance (Palagiano et al., 1995). The crystal structures of some imidazothiadiazole molecules, viz., 6-(4-bromophenyl)-2-(4-fluorobenzyl)imidazo[2,1-b][1,3,4] thiadiazole, 3-{[6-(4-Chlorophenyl)imidazo[2,1-b][1,3,4]thiadiazol-2-yl] methyl}-1,2-benzoxazole (Banu et al., 2011a,b), 2-isobutyl-6-(4-methoxyphenyl)imidazo[2,1-b][1,3,4]thiadiazole and 6-(4-chlorophenyl)-2-isobutylimidazo[2,1-b][1,3,4]thiadiazole (Fun et al., 2011a,b) have been reported.
In the title compound, C10H8N3SCl, the dihedral angle between the mean planes of the benzene and imidazo[2,1b][1,3,4]thiadiazole rings is 6.0 (9)° (Fig. 1). Bond lengths are in normal ranges (Allen et al., 1987). In the crystal, molecules are assembled by the formation of centrosymmetric dimers by π-stacking of thiadiazole and benzene rings of neighboring molecules (centroid–centroid distance = 3.6938 (11) Å) along [010] (Fig. 2). Additional weak π-stacking interactions involving nearby benzene rings (centroid-centroid distance = 3.7739 (11) Å) are also observed.
For related imidazothiadiazole derivatives and their pharmacological potential, see: Palagiano et al. (1995). For related structures, see: Banu et al. (2011a,b); Fun et al. (2011a,b). For standard bond lengths, see Allen et al. (1987).
Data collection: CrysAlis PRO (Agilent, 2012); cell
CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis RED (Agilent, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C10H6ClN3S | F(000) = 480 |
Mr = 235.70 | Dx = 1.676 Mg m−3 |
Monoclinic, P21/n | Cu Kα radiation, λ = 1.54184 Å |
Hall symbol: -P 2yn | Cell parameters from 2788 reflections |
a = 5.43804 (19) Å | θ = 3.2–72.4° |
b = 12.4222 (4) Å | µ = 5.37 mm−1 |
c = 14.1684 (4) Å | T = 173 K |
β = 100.269 (3)° | Chunk, colorless |
V = 941.77 (5) Å3 | 0.26 × 0.12 × 0.06 mm |
Z = 4 |
Agilent Xcalibur (Eos, Gemini) diffractometer | 1846 independent reflections |
Radiation source: Enhance (Cu) X-ray Source | 1650 reflections with I > 2σ(I)) |
Graphite monochromator | Rint = 0.046 |
Detector resolution: 16.0416 pixels mm-1 | θmax = 72.5°, θmin = 4.8° |
ω scans | h = −6→6 |
Absorption correction: multi-scan (CrysAlis PRO and CrysAlis RED; Agilent, 2012) | k = −12→15 |
Tmin = 0.691, Tmax = 1.000 | l = −17→13 |
5495 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.036 | H-atom parameters constrained |
wR(F2) = 0.100 | w = 1/[σ2(Fo2) + (0.0559P)2 + 0.2711P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max = 0.001 |
1846 reflections | Δρmax = 0.36 e Å−3 |
137 parameters | Δρmin = −0.23 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0028 (5) |
C10H6ClN3S | V = 941.77 (5) Å3 |
Mr = 235.70 | Z = 4 |
Monoclinic, P21/n | Cu Kα radiation |
a = 5.43804 (19) Å | µ = 5.37 mm−1 |
b = 12.4222 (4) Å | T = 173 K |
c = 14.1684 (4) Å | 0.26 × 0.12 × 0.06 mm |
β = 100.269 (3)° |
Agilent Xcalibur (Eos, Gemini) diffractometer | 1846 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO and CrysAlis RED; Agilent, 2012) | 1650 reflections with I > 2σ(I)) |
Tmin = 0.691, Tmax = 1.000 | Rint = 0.046 |
5495 measured reflections |
R[F2 > 2σ(F2)] = 0.036 | 0 restraints |
wR(F2) = 0.100 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.36 e Å−3 |
1846 reflections | Δρmin = −0.23 e Å−3 |
137 parameters |
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 > 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. |
x | y | z | Uiso*/Ueq | ||
Cl1 | 0.35900 (10) | 0.10200 (4) | 0.67741 (4) | 0.02949 (18) | |
S1 | 0.39725 (10) | 0.62878 (4) | 0.24567 (3) | 0.02652 (18) | |
N1 | 0.0469 (3) | 0.61595 (14) | 0.34925 (13) | 0.0253 (4) | |
N2 | 0.2006 (3) | 0.52794 (13) | 0.36757 (12) | 0.0199 (4) | |
N3 | 0.5314 (3) | 0.43233 (13) | 0.34504 (12) | 0.0222 (4) | |
C1 | 0.1320 (4) | 0.67447 (17) | 0.28675 (15) | 0.0261 (4) | |
H1 | 0.0545 | 0.7386 | 0.2645 | 0.031* | |
C2 | 0.3979 (4) | 0.51895 (15) | 0.32099 (13) | 0.0208 (4) | |
C3 | 0.2043 (4) | 0.44025 (16) | 0.42652 (14) | 0.0217 (4) | |
H3 | 0.0929 | 0.4235 | 0.4671 | 0.026* | |
C4 | 0.4101 (4) | 0.38271 (15) | 0.41207 (13) | 0.0190 (4) | |
C5 | 0.5067 (3) | 0.28278 (15) | 0.46084 (13) | 0.0192 (4) | |
C6 | 0.3963 (3) | 0.24196 (15) | 0.53512 (14) | 0.0205 (4) | |
H6 | 0.2605 | 0.2769 | 0.5531 | 0.025* | |
C7 | 0.4911 (4) | 0.14891 (16) | 0.58176 (13) | 0.0213 (4) | |
C8 | 0.6921 (4) | 0.09440 (16) | 0.55644 (16) | 0.0258 (4) | |
H8 | 0.7526 | 0.0317 | 0.5881 | 0.031* | |
C9 | 0.8008 (4) | 0.13562 (16) | 0.48276 (15) | 0.0254 (4) | |
H9 | 0.9360 | 0.1001 | 0.4650 | 0.030* | |
C10 | 0.7107 (4) | 0.22930 (15) | 0.43499 (14) | 0.0219 (4) | |
H10 | 0.7861 | 0.2563 | 0.3860 | 0.026* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0325 (3) | 0.0305 (3) | 0.0269 (3) | 0.00059 (19) | 0.0091 (2) | 0.00925 (19) |
S1 | 0.0346 (3) | 0.0247 (3) | 0.0222 (3) | 0.00174 (19) | 0.0104 (2) | 0.00440 (18) |
N1 | 0.0239 (9) | 0.0224 (8) | 0.0297 (9) | 0.0063 (6) | 0.0050 (7) | 0.0021 (7) |
N2 | 0.0198 (8) | 0.0193 (8) | 0.0212 (8) | 0.0029 (6) | 0.0052 (6) | −0.0002 (6) |
N3 | 0.0228 (8) | 0.0234 (8) | 0.0221 (8) | 0.0031 (7) | 0.0087 (7) | 0.0004 (6) |
C1 | 0.0292 (11) | 0.0235 (10) | 0.0246 (10) | 0.0033 (8) | 0.0019 (8) | 0.0003 (8) |
C2 | 0.0243 (10) | 0.0224 (9) | 0.0167 (9) | −0.0007 (7) | 0.0069 (7) | −0.0006 (7) |
C3 | 0.0237 (10) | 0.0215 (9) | 0.0220 (9) | 0.0030 (7) | 0.0096 (8) | 0.0032 (7) |
C4 | 0.0195 (10) | 0.0208 (9) | 0.0166 (9) | 0.0000 (7) | 0.0027 (7) | −0.0023 (7) |
C5 | 0.0190 (9) | 0.0200 (9) | 0.0181 (9) | −0.0005 (7) | 0.0021 (7) | −0.0034 (7) |
C6 | 0.0194 (9) | 0.0220 (9) | 0.0203 (9) | 0.0013 (7) | 0.0045 (7) | −0.0021 (7) |
C7 | 0.0212 (10) | 0.0228 (9) | 0.0197 (9) | −0.0031 (8) | 0.0035 (8) | 0.0002 (7) |
C8 | 0.0256 (10) | 0.0220 (10) | 0.0289 (11) | 0.0044 (8) | 0.0023 (9) | 0.0022 (8) |
C9 | 0.0220 (10) | 0.0258 (10) | 0.0292 (10) | 0.0043 (8) | 0.0069 (8) | −0.0028 (8) |
C10 | 0.0229 (10) | 0.0221 (9) | 0.0214 (9) | −0.0003 (8) | 0.0063 (8) | −0.0023 (7) |
Cl1—C7 | 1.7432 (19) | C4—C5 | 1.471 (3) |
S1—C2 | 1.7318 (19) | C5—C6 | 1.397 (3) |
S1—C1 | 1.744 (2) | C5—C10 | 1.397 (3) |
N1—C1 | 1.293 (3) | C6—C7 | 1.385 (3) |
N1—N2 | 1.373 (2) | C6—H6 | 0.9300 |
N2—C2 | 1.361 (3) | C7—C8 | 1.386 (3) |
N2—C3 | 1.371 (2) | C8—C9 | 1.386 (3) |
N3—C2 | 1.309 (2) | C8—H8 | 0.9300 |
N3—C4 | 1.393 (2) | C9—C10 | 1.391 (3) |
C1—H1 | 0.9300 | C9—H9 | 0.9300 |
C3—C4 | 1.373 (3) | C10—H10 | 0.9300 |
C3—H3 | 0.9300 | ||
C2—S1—C1 | 87.81 (9) | C6—C5—C10 | 119.54 (18) |
C1—N1—N2 | 107.27 (17) | C6—C5—C4 | 119.66 (17) |
C2—N2—C3 | 107.63 (16) | C10—C5—C4 | 120.79 (18) |
C2—N2—N1 | 118.68 (16) | C7—C6—C5 | 119.29 (17) |
C3—N2—N1 | 133.69 (17) | C7—C6—H6 | 120.4 |
C2—N3—C4 | 103.49 (15) | C5—C6—H6 | 120.4 |
N1—C1—S1 | 117.63 (16) | C6—C7—C8 | 121.87 (18) |
N1—C1—H1 | 121.2 | C6—C7—Cl1 | 118.69 (15) |
S1—C1—H1 | 121.2 | C8—C7—Cl1 | 119.41 (16) |
N3—C2—N2 | 112.95 (17) | C9—C8—C7 | 118.44 (19) |
N3—C2—S1 | 138.46 (15) | C9—C8—H8 | 120.8 |
N2—C2—S1 | 108.59 (14) | C7—C8—H8 | 120.8 |
N2—C3—C4 | 104.29 (16) | C8—C9—C10 | 121.00 (19) |
N2—C3—H3 | 127.9 | C8—C9—H9 | 119.5 |
C4—C3—H3 | 127.9 | C10—C9—H9 | 119.5 |
C3—C4—N3 | 111.64 (16) | C9—C10—C5 | 119.86 (18) |
C3—C4—C5 | 126.96 (18) | C9—C10—H10 | 120.1 |
N3—C4—C5 | 121.37 (17) | C5—C10—H10 | 120.1 |
C1—N1—N2—C2 | 0.2 (2) | C2—N3—C4—C3 | 0.4 (2) |
C1—N1—N2—C3 | 179.7 (2) | C2—N3—C4—C5 | −177.68 (17) |
N2—N1—C1—S1 | 0.3 (2) | C3—C4—C5—C6 | −4.9 (3) |
C2—S1—C1—N1 | −0.45 (17) | N3—C4—C5—C6 | 172.90 (17) |
C4—N3—C2—N2 | −0.1 (2) | C3—C4—C5—C10 | 176.33 (19) |
C4—N3—C2—S1 | 179.75 (18) | N3—C4—C5—C10 | −5.9 (3) |
C3—N2—C2—N3 | −0.2 (2) | C10—C5—C6—C7 | −0.1 (3) |
N1—N2—C2—N3 | 179.44 (17) | C4—C5—C6—C7 | −178.88 (17) |
C3—N2—C2—S1 | 179.87 (13) | C5—C6—C7—C8 | −0.4 (3) |
N1—N2—C2—S1 | −0.5 (2) | C5—C6—C7—Cl1 | 177.50 (14) |
C1—S1—C2—N3 | −179.4 (2) | C6—C7—C8—C9 | 0.5 (3) |
C1—S1—C2—N2 | 0.47 (14) | Cl1—C7—C8—C9 | −177.37 (15) |
C2—N2—C3—C4 | 0.5 (2) | C7—C8—C9—C10 | −0.1 (3) |
N1—N2—C3—C4 | −179.12 (19) | C8—C9—C10—C5 | −0.4 (3) |
N2—C3—C4—N3 | −0.6 (2) | C6—C5—C10—C9 | 0.5 (3) |
N2—C3—C4—C5 | 177.43 (17) | C4—C5—C10—C9 | 179.27 (18) |
Experimental details
Crystal data | |
Chemical formula | C10H6ClN3S |
Mr | 235.70 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 173 |
a, b, c (Å) | 5.43804 (19), 12.4222 (4), 14.1684 (4) |
β (°) | 100.269 (3) |
V (Å3) | 941.77 (5) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 5.37 |
Crystal size (mm) | 0.26 × 0.12 × 0.06 |
Data collection | |
Diffractometer | Agilent Xcalibur (Eos, Gemini) |
Absorption correction | Multi-scan (CrysAlis PRO and CrysAlis RED; Agilent, 2012) |
Tmin, Tmax | 0.691, 1.000 |
No. of measured, independent and observed [I > 2σ(I))] reflections | 5495, 1846, 1650 |
Rint | 0.046 |
(sin θ/λ)max (Å−1) | 0.619 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.036, 0.100, 1.06 |
No. of reflections | 1846 |
No. of parameters | 137 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.36, −0.23 |
Computer programs: CrysAlis PRO (Agilent, 2012), CrysAlis RED (Agilent, 2012), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006), SHELXTL (Sheldrick, 2008).
Acknowledgements
ASP thanks the UOM for research facilities. JPJ acknowledges the NSF–MRI program (grant No. CHE-1039027) for funds to purchase the X-ray diffractometer.
References
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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.
Many imidazothiadiazole derivatives have been reported to possess diverse medicinal properties such as anthelmintic, antimicrobial, anti-inflammatory, antipyretic, analgesic properties and many other activities of therapeutic significance (Palagiano et al., 1995). The crystal structures of some imidazothiadiazole molecules, viz., 6-(4-bromophenyl)-2-(4-fluorobenzyl)imidazo[2,1-b][1,3,4] thiadiazole, 3-{[6-(4-Chlorophenyl)imidazo[2,1-b][1,3,4]thiadiazol-2-yl] methyl}-1,2-benzoxazole (Banu et al., 2011a,b), 2-isobutyl-6-(4-methoxyphenyl)imidazo[2,1-b][1,3,4]thiadiazole and 6-(4-chlorophenyl)-2-isobutylimidazo[2,1-b][1,3,4]thiadiazole (Fun et al., 2011a,b) have been reported.
In the title compound, C10H8N3SCl, the dihedral angle between the mean planes of the benzene and imidazo[2,1b][1,3,4]thiadiazole rings is 6.0 (9)° (Fig. 1). Bond lengths are in normal ranges (Allen et al., 1987). In the crystal, molecules are assembled by the formation of centrosymmetric dimers by π-stacking of thiadiazole and benzene rings of neighboring molecules (centroid–centroid distance = 3.6938 (11) Å) along [010] (Fig. 2). Additional weak π-stacking interactions involving nearby benzene rings (centroid-centroid distance = 3.7739 (11) Å) are also observed.