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

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ISSN: 2056-9890

2-Iso­butyl-6-(4-meth­­oxy­phen­yl)imidazo[2,1-b][1,3,4]thia­diazole

aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bDepartment of Chemistry, Mangalore University, Mangalore, Karnataka, India, and cSt. Philomena's College, Puttur, Dakshina Kannada, Karnataka, India
*Correspondence e-mail: hkfun@usm.my

(Received 17 December 2010; accepted 18 December 2010; online 8 January 2011)

In the title compound, C15H17N3OS, the dihedral angle between the statistically planar imidazo[2,1-b][1,3,4]thia­dia­zole fused-ring system (r.m.s. deviation = 0.002 Å) and the methyoxbenzene ring is 4.52 (6)°. In the crystal, mol­ecules are arranged into columns and stacked down the a axis. The crystal structure is stabilized by weak C—H⋯π and ππ inter­actions [centroid–centroid separations = 3.6053 (8) and 3.7088 (7) Å].

Related literature

For a related structure and background references to imidazo[2,1-b]-1,3,4-thia­diazole derivatives, see: Fun et al. (2011[Fun, H.-K., Hemamalini, M., Prasad, D. J., Castelino, P. A. & Anitha, V. V. (2011). Acta Cryst. E67, o254.]).

[Scheme 1]

Experimental

Crystal data
  • C15H17N3OS

  • Mr = 287.38

  • Triclinic, [P \overline 1]

  • a = 5.7139 (1) Å

  • b = 10.1795 (1) Å

  • c = 12.9689 (2) Å

  • α = 85.174 (1)°

  • β = 85.164 (1)°

  • γ = 80.690 (1)°

  • V = 739.84 (2) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.22 mm−1

  • T = 296 K

  • 0.43 × 0.31 × 0.17 mm

Data collection
  • Bruker SMART APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.911, Tmax = 0.964

  • 23503 measured reflections

  • 6213 independent reflections

  • 3805 reflections with I > 2σ(I)

  • Rint = 0.028

Refinement
  • R[F2 > 2σ(F2)] = 0.053

  • wR(F2) = 0.163

  • S = 1.03

  • 6213 reflections

  • 181 parameters

  • H-atom parameters constrained

  • Δρmax = 0.30 e Å−3

  • Δρmin = −0.28 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

Cg3 is the centroid of the C1–C6 benzene ring.

D—H⋯A D—H H⋯A DA D—H⋯A
C11—H11ACg3i 0.97 2.60 3.5063 (16) 155
Symmetry code: (i) -x+2, -y+2, -z+1.

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS 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 and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

As part of our ongoing synthetic and structural studies of imidazo[2,1-b]-1,3,4-thiadiazole derivatives (Fun et al., 2011), we now report the structure of the title compound, (I).

The mean plane through the imidazo[2,1-b]-1,3,4-thiadiazole ring and the methoxyphenyl moiety is essentially planar with the maximum deviation of 0.045 Å for atom C2 (Fig. 1). The isobutyl is twisted away from this mean plane with torsion angles of C9–C11–C12–C13 = 64.3 (2)° and C9–C11–C12–C14 = -172.81 (17)°. In the crystal structure, the molecules are arranged into columns and stacked down a axis (Fig. 2). The molecules are stabilized by the weak Cg1···Cg2i = 3.7088 (7) Å, Cg2···Cg2i = 3.6053 (8) Å and C11–H11A···Cg3i interactions [Cg1, Cg2 and Cg3 are centroids of S1/C9/N1/N2/C10, N2/C8/C7/N3/C10 and C–C6 ring respectively; (i) 2 - x, 2 - y, 1 - z].

Related literature top

For a related structure and background references to imidazo[2,1-b]-1,3,4-thiadiazole derivatives, see: Fun et al. (2011).

Experimental top

5-Isobutyl-1,3,4-thiadiazol-2-amine (1 molar equivalent) and 4-methoxyphenacylbromide (1 molar equivalent) are refluxed with ethanol for 4 h. The solvent was then distilled and the reaction mass was poured onto the crushed ice. The resulting solid that separated out was filtered and dried. The compound was re-crystallized using ethanol and DMF mixture to yield colourless blocks of (I). M.P.: 118–122°C.

Refinement top

All hydrogen atoms were positioned geometrically [C–H = 0.93–0.98 Å] and refined using a riding model, with Uiso(H) = 1.2 or 1.5Ueq(C).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); 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) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) with 30% probability ellipsoids for non-H atoms.
[Figure 2] Fig. 2. The crystal packing of (I), viewed down the a axis, showing molecules stacked down a axis.
2-Isobutyl-6-(4-methoxyphenyl)imidazo[2,1-b][1,3,4]thiadiazole top
Crystal data top
C15H17N3OSZ = 2
Mr = 287.38F(000) = 304
Triclinic, P1Dx = 1.290 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 5.7139 (1) ÅCell parameters from 6150 reflections
b = 10.1795 (1) Åθ = 2.5–30.1°
c = 12.9689 (2) ŵ = 0.22 mm1
α = 85.174 (1)°T = 296 K
β = 85.164 (1)°Block, colourless
γ = 80.690 (1)°0.43 × 0.31 × 0.17 mm
V = 739.84 (2) Å3
Data collection top
Bruker SMART APEXII CCD
diffractometer
6213 independent reflections
Radiation source: fine-focus sealed tube3805 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.028
ϕ and ω scansθmax = 34.5°, θmin = 1.6°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
h = 99
Tmin = 0.911, Tmax = 0.964k = 1616
23503 measured reflectionsl = 2020
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)] = 0.053Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.163H-atom parameters constrained
S = 1.03 w = 1/[σ2(Fo2) + (0.0765P)2 + 0.0748P]
where P = (Fo2 + 2Fc2)/3
6213 reflections(Δ/σ)max < 0.001
181 parametersΔρmax = 0.30 e Å3
0 restraintsΔρmin = 0.28 e Å3
Crystal data top
C15H17N3OSγ = 80.690 (1)°
Mr = 287.38V = 739.84 (2) Å3
Triclinic, P1Z = 2
a = 5.7139 (1) ÅMo Kα radiation
b = 10.1795 (1) ŵ = 0.22 mm1
c = 12.9689 (2) ÅT = 296 K
α = 85.174 (1)°0.43 × 0.31 × 0.17 mm
β = 85.164 (1)°
Data collection top
Bruker SMART APEXII CCD
diffractometer
6213 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
3805 reflections with I > 2σ(I)
Tmin = 0.911, Tmax = 0.964Rint = 0.028
23503 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0530 restraints
wR(F2) = 0.163H-atom parameters constrained
S = 1.03Δρmax = 0.30 e Å3
6213 reflectionsΔρmin = 0.28 e Å3
181 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
S11.14439 (6)1.02701 (4)0.26563 (3)0.05911 (14)
O11.1085 (2)0.33486 (12)0.78317 (9)0.0741 (3)
N10.7031 (2)1.05243 (12)0.33719 (9)0.0523 (3)
N20.82991 (18)0.94641 (11)0.39100 (8)0.0448 (2)
N31.16801 (18)0.81311 (11)0.42311 (8)0.0470 (2)
C11.2380 (2)0.58244 (13)0.57132 (10)0.0459 (3)
H1A1.36370.60300.52580.055*
C21.2769 (3)0.47212 (13)0.64264 (10)0.0498 (3)
H2A1.42610.41990.64420.060*
C31.0917 (3)0.44125 (14)0.71078 (10)0.0515 (3)
C40.8704 (3)0.52078 (17)0.70788 (12)0.0620 (4)
H4A0.74560.50080.75420.074*
C50.8345 (2)0.62946 (16)0.63658 (12)0.0541 (3)
H5A0.68520.68170.63540.065*
C61.0186 (2)0.66223 (12)0.56621 (9)0.0405 (2)
C70.9808 (2)0.77580 (12)0.48936 (9)0.0397 (2)
C80.7710 (2)0.85747 (13)0.47028 (10)0.0497 (3)
H8A0.62170.85330.50380.060*
C90.8461 (2)1.10357 (13)0.26920 (10)0.0473 (3)
C101.0665 (2)0.91576 (13)0.36590 (9)0.0441 (3)
C110.7678 (3)1.22647 (14)0.20133 (11)0.0571 (4)
H11A0.83701.29920.22400.069*
H11B0.59651.24930.21230.069*
C120.8305 (3)1.21810 (16)0.08633 (11)0.0642 (4)
H12A1.00261.19050.07540.077*
C130.7083 (6)1.1178 (2)0.04179 (17)0.1097 (9)
H13A0.74821.03220.07830.165*
H13B0.75941.11190.03030.165*
H13C0.53931.14550.04890.165*
C140.7663 (6)1.3557 (2)0.03141 (17)0.1117 (9)
H14A0.84611.41830.06070.167*
H14B0.59751.38360.04000.167*
H14C0.81481.35220.04110.167*
C151.3354 (4)0.25718 (19)0.79377 (16)0.0840 (6)
H15A1.32330.18630.84670.126*
H15B1.44360.31250.81270.126*
H15C1.39310.22000.72910.126*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.04595 (19)0.0694 (3)0.0549 (2)0.00092 (16)0.00022 (14)0.01745 (17)
O10.0866 (8)0.0673 (7)0.0650 (7)0.0162 (6)0.0051 (6)0.0229 (5)
N10.0439 (6)0.0567 (7)0.0504 (6)0.0074 (5)0.0069 (5)0.0047 (5)
N20.0364 (5)0.0504 (6)0.0438 (5)0.0022 (4)0.0044 (4)0.0022 (4)
N30.0361 (5)0.0551 (6)0.0462 (6)0.0009 (4)0.0031 (4)0.0060 (4)
C10.0453 (6)0.0489 (7)0.0394 (6)0.0004 (5)0.0018 (5)0.0001 (5)
C20.0532 (7)0.0483 (7)0.0440 (6)0.0019 (5)0.0021 (5)0.0004 (5)
C30.0644 (8)0.0468 (7)0.0441 (6)0.0126 (6)0.0077 (6)0.0034 (5)
C40.0531 (8)0.0731 (10)0.0584 (8)0.0177 (7)0.0027 (6)0.0119 (7)
C50.0394 (6)0.0654 (8)0.0546 (7)0.0063 (6)0.0001 (5)0.0060 (6)
C60.0395 (6)0.0448 (6)0.0374 (5)0.0054 (5)0.0040 (4)0.0050 (4)
C70.0372 (5)0.0445 (6)0.0365 (5)0.0023 (4)0.0035 (4)0.0050 (4)
C80.0375 (6)0.0565 (8)0.0505 (7)0.0008 (5)0.0019 (5)0.0051 (6)
C90.0514 (7)0.0489 (7)0.0394 (6)0.0027 (5)0.0096 (5)0.0042 (5)
C100.0364 (6)0.0528 (7)0.0409 (6)0.0022 (5)0.0038 (4)0.0010 (5)
C110.0711 (9)0.0495 (7)0.0465 (7)0.0050 (6)0.0117 (6)0.0006 (5)
C120.0702 (10)0.0673 (9)0.0486 (8)0.0017 (8)0.0023 (7)0.0078 (7)
C130.175 (3)0.0923 (15)0.0672 (12)0.0145 (17)0.0461 (15)0.0119 (11)
C140.164 (3)0.0872 (14)0.0717 (13)0.0059 (16)0.0039 (14)0.0319 (11)
C150.1056 (16)0.0615 (10)0.0816 (12)0.0074 (10)0.0270 (11)0.0232 (9)
Geometric parameters (Å, º) top
S1—C101.7290 (13)C6—C71.4622 (16)
S1—C91.7545 (14)C7—C81.3722 (17)
O1—C31.3690 (16)C8—H8A0.9300
O1—C151.416 (2)C9—C111.4966 (18)
N1—C91.2864 (19)C11—C121.510 (2)
N1—N21.3721 (14)C11—H11A0.9700
N2—C101.3554 (16)C11—H11B0.9700
N2—C81.3689 (16)C12—C131.503 (3)
N3—C101.3133 (15)C12—C141.521 (2)
N3—C71.3957 (16)C12—H12A0.9800
C1—C61.3825 (17)C13—H13A0.9600
C1—C21.3947 (17)C13—H13B0.9600
C1—H1A0.9300C13—H13C0.9600
C2—C31.379 (2)C14—H14A0.9600
C2—H2A0.9300C14—H14B0.9600
C3—C41.388 (2)C14—H14C0.9600
C4—C51.381 (2)C15—H15A0.9600
C4—H4A0.9300C15—H15B0.9600
C5—C61.3967 (18)C15—H15C0.9600
C5—H5A0.9300
C10—S1—C988.40 (6)N3—C10—N2112.76 (11)
C3—O1—C15117.66 (14)N3—C10—S1138.85 (10)
C9—N1—N2108.55 (11)N2—C10—S1108.39 (9)
C10—N2—C8107.69 (10)C9—C11—C12116.36 (12)
C10—N2—N1118.51 (11)C9—C11—H11A108.2
C8—N2—N1133.79 (11)C12—C11—H11A108.2
C10—N3—C7103.73 (10)C9—C11—H11B108.2
C6—C1—C2122.09 (12)C12—C11—H11B108.2
C6—C1—H1A119.0H11A—C11—H11B107.4
C2—C1—H1A119.0C13—C12—C11112.03 (16)
C3—C2—C1119.33 (13)C13—C12—C14110.67 (17)
C3—C2—H2A120.3C11—C12—C14109.10 (15)
C1—C2—H2A120.3C13—C12—H12A108.3
O1—C3—C2124.39 (14)C11—C12—H12A108.3
O1—C3—C4115.99 (14)C14—C12—H12A108.3
C2—C3—C4119.62 (13)C12—C13—H13A109.5
C5—C4—C3120.36 (14)C12—C13—H13B109.5
C5—C4—H4A119.8H13A—C13—H13B109.5
C3—C4—H4A119.8C12—C13—H13C109.5
C4—C5—C6121.14 (14)H13A—C13—H13C109.5
C4—C5—H5A119.4H13B—C13—H13C109.5
C6—C5—H5A119.4C12—C14—H14A109.5
C1—C6—C5117.46 (12)C12—C14—H14B109.5
C1—C6—C7121.12 (11)H14A—C14—H14B109.5
C5—C6—C7121.42 (11)C12—C14—H14C109.5
C8—C7—N3111.03 (11)H14A—C14—H14C109.5
C8—C7—C6127.62 (11)H14B—C14—H14C109.5
N3—C7—C6121.35 (10)O1—C15—H15A109.5
N2—C8—C7104.79 (11)O1—C15—H15B109.5
N2—C8—H8A127.6H15A—C15—H15B109.5
C7—C8—H8A127.6O1—C15—H15C109.5
N1—C9—C11122.38 (13)H15A—C15—H15C109.5
N1—C9—S1116.15 (10)H15B—C15—H15C109.5
C11—C9—S1121.36 (11)
C9—N1—N2—C100.23 (17)C10—N2—C8—C70.06 (15)
C9—N1—N2—C8179.94 (14)N1—N2—C8—C7179.67 (13)
C6—C1—C2—C30.3 (2)N3—C7—C8—N20.03 (15)
C15—O1—C3—C24.8 (2)C6—C7—C8—N2179.34 (11)
C15—O1—C3—C4175.43 (15)N2—N1—C9—C11176.23 (11)
C1—C2—C3—O1179.30 (13)N2—N1—C9—S10.04 (15)
C1—C2—C3—C40.4 (2)C10—S1—C9—N10.10 (12)
O1—C3—C4—C5179.11 (14)C10—S1—C9—C11176.13 (11)
C2—C3—C4—C50.7 (2)C7—N3—C10—N20.14 (15)
C3—C4—C5—C60.2 (2)C7—N3—C10—S1179.92 (13)
C2—C1—C6—C50.7 (2)C8—N2—C10—N30.13 (16)
C2—C1—C6—C7178.73 (12)N1—N2—C10—N3179.65 (11)
C4—C5—C6—C10.5 (2)C8—N2—C10—S1179.92 (9)
C4—C5—C6—C7178.95 (13)N1—N2—C10—S10.31 (15)
C10—N3—C7—C80.10 (14)C9—S1—C10—N3179.73 (16)
C10—N3—C7—C6179.31 (11)C9—S1—C10—N20.21 (10)
C1—C6—C7—C8175.00 (13)N1—C9—C11—C12129.32 (16)
C5—C6—C7—C84.5 (2)S1—C9—C11—C1254.69 (18)
C1—C6—C7—N34.31 (18)C9—C11—C12—C1364.3 (2)
C5—C6—C7—N3176.24 (12)C9—C11—C12—C14172.81 (17)
Hydrogen-bond geometry (Å, º) top
Cg3 is the centroid of the C1–C6 benzene ring.
D—H···AD—HH···AD···AD—H···A
C11—H11A···Cg3i0.972.603.5063 (16)155
Symmetry code: (i) x+2, y+2, z+1.

Experimental details

Crystal data
Chemical formulaC15H17N3OS
Mr287.38
Crystal system, space groupTriclinic, P1
Temperature (K)296
a, b, c (Å)5.7139 (1), 10.1795 (1), 12.9689 (2)
α, β, γ (°)85.174 (1), 85.164 (1), 80.690 (1)
V3)739.84 (2)
Z2
Radiation typeMo Kα
µ (mm1)0.22
Crystal size (mm)0.43 × 0.31 × 0.17
Data collection
DiffractometerBruker SMART APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.911, 0.964
No. of measured, independent and
observed [I > 2σ(I)] reflections
23503, 6213, 3805
Rint0.028
(sin θ/λ)max1)0.797
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.053, 0.163, 1.03
No. of reflections6213
No. of parameters181
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.30, 0.28

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
Cg3 is the centroid of the C1–C6 benzene ring.
D—H···AD—HH···AD···AD—H···A
C11—H11A···Cg3i0.972.603.5063 (16)155
Symmetry code: (i) x+2, y+2, z+1.
 

Footnotes

Thomson Reuters ResearcherID: A-3561-2009.

§Thomson Reuters ResearcherID: A-5523-2009.

Acknowledgements

HKF and CSY thank Universiti Sains Malaysia (USM) for the Research University Grant No. 1001/PFIZIK/811160.

References

First citationBruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFun, H.-K., Hemamalini, M., Prasad, D. J., Castelino, P. A. & Anitha, V. V. (2011). Acta Cryst. E67, o254.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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