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Acta Cryst. (2011). E67, o184-o185    [ doi:10.1107/S1600536810052359 ]

2-[6-(4-Chlorophenyl)imidazo[2,1-b][1,3]thiazol-2-yl]-N'-[(E)-4-methoxybenzylidene]acetohydrazide

M. Akkurt, N. U. Güzeldemirci, B. Karaman and O. Büyükgüngör

Abstract top

In the imidazo[2,1-b][1,3]thiazole group of the title compound, C21H17ClN4O2S, the dihedral angle between the thiazole and imidazole rings is 1.9 (2)°. The mean plane of this group makes dihedral angles of 5.5 (2) and 39.9 (2)° with the benzene rings of the chlorophenyl and methoxyphenyl groups, respectively. The dihedral angle between these two benzene rings is 34.4 (2)°. In the crystal, molecules are connected to each other by intermolecular N-H...O hydrogen bonds along the b axis, generating a C(4) chain. Weak C-H...[pi] interactions also occur.

Comment top

Imidazo[2,1-b][1,3]thiazole derivatives have demonstrated a broad range of biological activities, including immunomodulatory (Hanson et al., 1991), antibacterial (Juspin et al., 2010), antiviral (Barradas, et al.., 2008), antitumoral (Andreani et al., 2005) and antiinflammatory (Shilcrat et al., 1991).

As part of our on-going research aiming on the synthesis of imidazo[2,1-b]thiazoles (Gürsoy & Ulusoy Güzeldemirci, 2007; Ulusoy Güzeldemirci & Küçükbasmacı, 2010) and their crystal structures (Akkurt et al., 2007, 2008), we report here the crystal structure of the title compound (I).

In the title molecule of (I), (Fig. 1), the bond lengths and bond angles are normal (Allen et al., 1987). The imidazo[2,1-b][1,3]thiazole group is essantially planar with a dihedral angle of 1.9 (2) ° between the thiazole and imidazole rings makes a dihedral angle of 2.99 (15)°.

The mean plane of the imidazo[2,1-b][1,3]thiazole group makes dihedral angles of 5.5 (2) and 39.9 (2) ° with the benzene rings of the chlorophenyl and methoxyphenyl groups, respectively. The dihedral angle between these two phenyl rings is 34.4 (2) °.

Molecules are connected to each other by intermolecular N—H···O hydrogen bonds along the b axis, generating a C(4) chain (Table 1, Fig. 2). In the crystal structure, a weak C—H···π interaction occurs.

Related literature top

For the biological activity of imidazo[2,1-b][1,3]thiazole derivatives, see: Andreani et al. (2005); Barradas et al. (2008); Hanson et al. (1991); Juspin et al. (2010); Shilcrat et al. (1991). For details of the synthesis, see: Gürsoy & Ulusoy Güzeldemirci (2007); Ulusoy Güzeldemirci & Küçükbasmacı (2010). For related structures, see: Akkurt et al. (2007, 2008). For bond-length data, see: Allen et al. (1987).

Experimental top

[6-(4-Chlorophenyl)imidazo[2,1-b]thiazol-3-yl]acetic acid hydrazide (0.005 mol) and 4-methoxybenzaldehyde (0.005 mol) were heated in 100 ml ethanol for 5 h. The precipitate obtained was purified by washing with hot ethanol. Yield: 88%. M.p.: 511.5–512.6 K. IR [ν, cm-1, KBr]: 3212, 3138 (N—H), 1660 (C=O). Analysis calculated for C21H17ClN4O2S: C 59.36, H 4.03, N 13.19%. Found: C 59.25, H 3.94, N 13.18%.

Refinement top

All H atoms were placed in geometrically idealized positions and refined using a riding model, with N—H = 0.86 Å and C—H = 0.93, 0.97 and 0.96 Å for aromatic, methylene and methyl H, respectively, and Uiso(H) = 1.5Ueq(C) for methyl H, and Uiso(H) =1.2Ueq(C,N) for all other H atoms.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. View of the title molecule, with the atom numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 30% probability level.
[Figure 2] Fig. 2. Partial view of the crystal packing showing the N—H···O, C—H···N hydrogen bonding interactions and C—H···π interactions of (I) in the unit cell. All H atoms not involved in hydrogen bonding are omitted for clarity. Cg1 is the centroid of ring N1/N2/C7—C9. [Symmetry code: (a) x, 1 + y, z].
2-[6-(4-Chlorophenyl)imidazo[2,1-b][1,3]thiazol-2-yl]- N'-[(E)-4-methoxybenzylidene]acetohydrazide top
Crystal data top
C21H17ClN4O2SF(000) = 880
Mr = 424.91Dx = 1.439 Mg m−3
Orthorhombic, Pca21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2acCell parameters from 15357 reflections
a = 13.4591 (6) Åθ = 1.3–25.1°
b = 4.7834 (3) ŵ = 0.33 mm−1
c = 30.4674 (14) ÅT = 296 K
V = 1961.50 (18) Å3Prism, colourless
Z = 40.38 × 0.26 × 0.13 mm
Data collection top
Stoe IPDS 2
diffractometer		3304 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus2754 reflections with I > 2σ(I)
plane graphiteRint = 0.092
Detector resolution: 6.67 pixels mm-1θmax = 24.6°, θmin = 1.3°
ω scansh = −15→15
Absorption correction: integration
(X-RED32; Stoe & Cie, 2002)		k = −5→5
Tmin = 0.890, Tmax = 0.961l = −35→35
10765 measured reflections
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.059 w = 1/[σ2(Fo2) + (0.1136P)2]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.164(Δ/σ)max = 0.001
S = 1.01Δρmax = 0.20 e Å−3
3304 reflectionsΔρmin = −0.20 e Å−3
265 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), FC*=KFC[1+0.001XFC2Λ3/SIN(2Θ)]-1/4
1 restraintExtinction coefficient: 0.010 (2)
Primary atom site location: structure-invariant direct methodsAbsolute structure: Flack (1983), 1611 Friedel pairs
Secondary atom site location: difference Fourier mapFlack parameter: 0.15 (11)
Crystal data top
C21H17ClN4O2SV = 1961.50 (18) Å3
Mr = 424.91Z = 4
Orthorhombic, Pca21Mo Kα radiation
a = 13.4591 (6) ŵ = 0.33 mm−1
b = 4.7834 (3) ÅT = 296 K
c = 30.4674 (14) Å0.38 × 0.26 × 0.13 mm
Data collection top
Stoe IPDS 2
diffractometer		3304 independent reflections
Absorption correction: integration
(X-RED32; Stoe & Cie, 2002)		2754 reflections with I > 2σ(I)
Tmin = 0.890, Tmax = 0.961Rint = 0.092
10765 measured reflectionsθmax = 24.6°
Refinement top
R[F2 > 2σ(F2)] = 0.059H-atom parameters constrained
wR(F2) = 0.164Δρmax = 0.20 e Å−3
S = 1.01Δρmin = −0.20 e Å−3
3304 reflectionsAbsolute structure: Flack (1983), 1611 Friedel pairs
265 parametersFlack parameter: 0.15 (11)
1 restraint
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating -R-factor-obs 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
Cl10.54087 (14)1.5430 (3)0.72891 (5)0.1113 (6)
S11.01901 (8)0.7353 (3)0.53219 (5)0.0824 (4)
O10.6911 (2)0.6101 (5)0.46534 (10)0.0706 (10)
O20.1795 (3)0.1793 (9)0.30456 (13)0.0947 (12)
N10.8812 (3)0.9668 (8)0.59159 (12)0.0709 (11)
N20.8350 (2)0.6242 (7)0.54579 (11)0.0612 (10)
N30.6651 (3)0.1742 (7)0.43926 (12)0.0689 (11)
N40.5793 (3)0.2476 (7)0.41650 (13)0.0676 (11)
C10.7215 (3)1.0549 (9)0.62971 (14)0.0647 (12)
C20.7662 (4)1.2522 (10)0.65723 (15)0.0770 (14)
C30.7105 (4)1.3995 (11)0.68731 (17)0.0863 (19)
C40.6104 (4)1.3556 (10)0.69031 (16)0.0800 (19)
C50.5640 (4)1.1665 (12)0.66394 (17)0.0823 (17)
C60.6196 (4)1.0159 (11)0.63367 (15)0.0767 (17)
C70.7810 (3)0.9024 (9)0.59711 (15)0.0653 (12)
C80.7513 (3)0.6957 (8)0.56975 (14)0.0630 (12)
C90.9110 (3)0.7939 (9)0.56040 (15)0.0680 (12)
C100.8635 (3)0.4461 (8)0.51164 (14)0.0620 (12)
C110.9596 (3)0.4809 (10)0.50111 (17)0.0720 (17)
C120.7937 (3)0.2362 (8)0.49197 (16)0.0655 (14)
C130.7124 (3)0.3618 (8)0.46392 (14)0.0596 (11)
C140.5417 (4)0.0495 (10)0.39367 (16)0.0723 (16)
C150.4478 (4)0.0818 (9)0.37059 (15)0.0700 (14)
C160.3780 (4)0.2839 (9)0.38208 (16)0.0730 (16)
C170.2884 (4)0.3090 (11)0.36042 (17)0.0790 (17)
C180.2698 (4)0.1353 (10)0.32490 (17)0.0750 (16)
C190.3377 (4)−0.0638 (10)0.31242 (17)0.0817 (17)
C200.4246 (4)−0.0884 (10)0.33545 (18)0.0783 (17)
C210.1516 (5)−0.0120 (16)0.2706 (2)0.115 (3)
H20.834201.284300.655200.0920*
H30.741101.529000.705600.1030*
H3A0.687700.006500.437400.0830*
H50.495801.138400.666200.0980*
H60.588000.886400.615700.0920*
H80.688100.618200.567500.0760*
H110.991300.378600.479300.0860*
H12A0.763200.130000.515500.0780*
H12B0.831800.106700.474200.0780*
H140.57540−0.119800.391800.0870*
H160.392200.405600.405000.0880*
H170.241400.439600.369500.0950*
H190.32490−0.180200.288600.0980*
H200.46990−0.225400.327100.0940*
H21A0.20130−0.011500.248000.1720*
H21B0.088900.044000.258400.1720*
H21C0.14580−0.196700.282700.1720*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.1479 (14)0.0934 (9)0.0926 (8)0.0296 (9)0.0312 (9)−0.0020 (8)
S10.0569 (5)0.0919 (8)0.0983 (8)−0.0039 (5)0.0019 (6)−0.0118 (7)
O10.0780 (18)0.0475 (13)0.0862 (18)0.0048 (13)−0.0115 (16)0.0021 (14)
O20.086 (2)0.102 (2)0.096 (2)0.004 (2)−0.020 (2)−0.020 (2)
N10.0618 (18)0.076 (2)0.075 (2)0.0001 (17)−0.0067 (18)−0.005 (2)
N20.0554 (17)0.0586 (16)0.0697 (19)−0.0003 (14)−0.0055 (15)0.0055 (15)
N30.075 (2)0.0517 (17)0.080 (2)0.0084 (15)−0.0098 (19)0.0007 (16)
N40.069 (2)0.0569 (17)0.077 (2)0.0017 (15)−0.0060 (17)−0.0023 (17)
C10.068 (2)0.063 (2)0.063 (2)0.0025 (19)−0.0017 (18)0.0064 (18)
C20.093 (3)0.068 (2)0.070 (2)−0.006 (2)−0.004 (2)0.000 (2)
C30.108 (4)0.077 (3)0.074 (3)0.001 (3)−0.007 (3)−0.010 (3)
C40.099 (4)0.070 (3)0.071 (3)0.017 (2)0.009 (3)0.002 (2)
C50.079 (3)0.088 (3)0.080 (3)0.015 (3)0.007 (3)0.003 (3)
C60.074 (3)0.083 (3)0.073 (3)0.006 (2)0.005 (2)0.003 (2)
C70.067 (2)0.062 (2)0.067 (2)0.0017 (18)−0.004 (2)0.007 (2)
C80.057 (2)0.062 (2)0.070 (2)−0.0038 (18)0.0016 (18)0.0042 (19)
C90.060 (2)0.069 (2)0.075 (2)0.0014 (19)−0.003 (2)0.003 (2)
C100.066 (2)0.055 (2)0.065 (2)0.0055 (17)−0.0037 (19)0.0025 (18)
C110.062 (3)0.072 (3)0.082 (3)0.0067 (19)−0.002 (2)0.000 (2)
C120.068 (2)0.0504 (19)0.078 (3)0.0026 (17)−0.006 (2)0.0034 (18)
C130.066 (2)0.0478 (18)0.065 (2)−0.0003 (16)0.0044 (19)0.0037 (17)
C140.076 (3)0.064 (2)0.077 (3)0.002 (2)−0.001 (2)−0.002 (2)
C150.078 (3)0.061 (2)0.071 (2)−0.001 (2)0.000 (2)0.000 (2)
C160.077 (3)0.068 (2)0.074 (3)−0.002 (2)−0.005 (2)−0.012 (2)
C170.072 (3)0.076 (3)0.089 (3)0.005 (2)−0.003 (2)−0.013 (2)
C180.071 (3)0.080 (3)0.074 (2)−0.006 (2)−0.010 (2)−0.001 (2)
C190.080 (3)0.081 (3)0.084 (3)0.000 (2)−0.009 (2)−0.018 (2)
C200.074 (3)0.068 (3)0.093 (3)0.005 (2)−0.005 (2)−0.013 (2)
C210.113 (5)0.123 (5)0.108 (4)0.001 (4)−0.034 (4)−0.034 (4)
Geometric parameters (Å, °) top
Cl1—C41.750 (5)C12—C131.513 (6)
S1—C91.712 (4)C14—C151.455 (7)
S1—C111.737 (5)C15—C201.381 (7)
O1—C131.223 (5)C15—C161.393 (7)
O2—C181.380 (7)C16—C171.380 (7)
O2—C211.431 (8)C17—C181.387 (7)
N1—C71.394 (6)C18—C191.374 (7)
N1—C91.322 (6)C19—C201.369 (8)
N2—C81.385 (5)C2—H20.9300
N2—C91.380 (5)C3—H30.9300
N2—C101.398 (5)C5—H50.9300
N3—N41.392 (6)C6—H60.9300
N3—C131.332 (5)C8—H80.9300
N4—C141.280 (6)C11—H110.9300
N3—H3A0.8600C12—H12A0.9700
C1—C61.389 (7)C12—H12B0.9700
C1—C71.470 (6)C14—H140.9300
C1—C21.399 (6)C16—H160.9300
C2—C31.378 (7)C17—H170.9300
C3—C41.367 (8)C19—H190.9300
C4—C51.362 (7)C20—H200.9300
C5—C61.389 (7)C21—H21A0.9600
C7—C81.354 (6)C21—H21B0.9600
C10—C121.500 (6)C21—H21C0.9600
C10—C111.343 (6)
C9—S1—C1189.9 (2)C16—C17—C18118.6 (5)
C18—O2—C21117.3 (5)O2—C18—C19124.6 (5)
C7—N1—C9104.0 (4)O2—C18—C17114.7 (5)
C8—N2—C9106.7 (3)C17—C18—C19120.7 (5)
C8—N2—C10140.0 (3)C18—C19—C20119.1 (5)
C9—N2—C10113.3 (3)C15—C20—C19122.7 (5)
N4—N3—C13120.5 (3)C1—C2—H2120.00
N3—N4—C14114.3 (4)C3—C2—H2120.00
C13—N3—H3A120.00C2—C3—H3120.00
N4—N3—H3A120.00C4—C3—H3120.00
C2—C1—C7120.4 (4)C4—C5—H5120.00
C2—C1—C6117.6 (4)C6—C5—H5120.00
C6—C1—C7122.0 (4)C1—C6—H6119.00
C1—C2—C3120.7 (5)C5—C6—H6119.00
C2—C3—C4120.2 (5)N2—C8—H8127.00
C3—C4—C5121.0 (5)C7—C8—H8127.00
Cl1—C4—C5119.5 (4)S1—C11—H11123.00
Cl1—C4—C3119.6 (4)C10—C11—H11123.00
C4—C5—C6119.3 (5)C10—C12—H12A109.00
C1—C6—C5121.3 (5)C10—C12—H12B109.00
N1—C7—C1120.0 (4)C13—C12—H12A109.00
N1—C7—C8111.9 (4)C13—C12—H12B109.00
C1—C7—C8128.2 (4)H12A—C12—H12B108.00
N2—C8—C7105.4 (3)N4—C14—H14119.00
N1—C9—N2112.0 (4)C15—C14—H14119.00
S1—C9—N1136.1 (3)C15—C16—H16119.00
S1—C9—N2111.8 (3)C17—C16—H16119.00
N2—C10—C11111.5 (4)C16—C17—H17121.00
N2—C10—C12122.2 (3)C18—C17—H17121.00
C11—C10—C12126.2 (4)C18—C19—H19120.00
S1—C11—C10113.6 (4)C20—C19—H19120.00
C10—C12—C13114.4 (3)C15—C20—H20119.00
N3—C13—C12113.4 (3)C19—C20—H20119.00
O1—C13—C12122.4 (4)O2—C21—H21A110.00
O1—C13—N3124.2 (4)O2—C21—H21B109.00
N4—C14—C15121.9 (4)O2—C21—H21C109.00
C16—C15—C20116.9 (5)H21A—C21—H21B110.00
C14—C15—C16122.6 (4)H21A—C21—H21C110.00
C14—C15—C20120.6 (4)H21B—C21—H21C109.00
C15—C16—C17122.0 (4)
C11—S1—C9—N2−0.2 (3)C6—C1—C7—C8−5.7 (7)
C11—S1—C9—N1−177.4 (5)C2—C1—C7—C8176.1 (4)
C9—S1—C11—C100.4 (4)C1—C2—C3—C4−0.5 (7)
C21—O2—C18—C17−173.8 (5)C2—C3—C4—Cl1179.6 (4)
C21—O2—C18—C195.6 (8)C2—C3—C4—C50.2 (8)
C7—N1—C9—N20.2 (5)Cl1—C4—C5—C6−179.3 (4)
C7—N1—C9—S1177.4 (4)C3—C4—C5—C60.2 (8)
C9—N1—C7—C1−180.0 (4)C4—C5—C6—C1−0.2 (8)
C9—N1—C7—C8−0.1 (5)C1—C7—C8—N2179.9 (4)
C9—N2—C8—C70.1 (4)N1—C7—C8—N20.0 (5)
C10—N2—C9—N1177.8 (4)C11—C10—C12—C13−111.4 (5)
C10—N2—C8—C7−177.0 (5)N2—C10—C11—S1−0.6 (5)
C8—N2—C9—S1−178.1 (3)C12—C10—C11—S1−177.6 (3)
C9—N2—C10—C12177.6 (4)N2—C10—C12—C1371.8 (5)
C10—N2—C9—S1−0.1 (4)C10—C12—C13—O1−16.2 (6)
C8—N2—C9—N1−0.2 (5)C10—C12—C13—N3166.1 (4)
C8—N2—C10—C12−5.4 (7)N4—C14—C15—C20158.2 (5)
C9—N2—C10—C110.4 (5)N4—C14—C15—C16−21.1 (7)
C8—N2—C10—C11177.4 (5)C14—C15—C20—C19−179.3 (5)
N4—N3—C13—O1−7.0 (7)C16—C15—C20—C190.1 (7)
C13—N3—N4—C14179.3 (4)C14—C15—C16—C17−178.8 (5)
N4—N3—C13—C12170.6 (4)C20—C15—C16—C171.9 (7)
N3—N4—C14—C15175.0 (4)C15—C16—C17—C18−3.0 (8)
C2—C1—C7—N1−4.1 (6)C16—C17—C18—C192.1 (8)
C2—C1—C6—C5−0.2 (7)C16—C17—C18—O2−178.5 (4)
C6—C1—C2—C30.5 (7)O2—C18—C19—C20−179.6 (5)
C7—C1—C6—C5−178.4 (5)C17—C18—C19—C20−0.2 (8)
C7—C1—C2—C3178.8 (4)C18—C19—C20—C15−0.9 (8)
C6—C1—C7—N1174.1 (4)
Hydrogen-bond geometry (Å, °) top
Cg1 is the centroid of the N1/N2/C7–C9 ring.
D—H···AD—HH···AD···AD—H···A
N3—H3A···O1i0.862.082.835 (4)146
C2—H2···N10.932.542.874 (6)101
C12—H12A···Cg1i0.972.543.282 (5)133
Symmetry codes: (i) x, y−1, z.
Table 1
Hydrogen-bond geometry (Å, °) top
Cg1 is the centroid of the N1/N2/C7–C9 ring.
D—H···AD—HH···AD···AD—H···A
N3—H3A···O1i0.862.082.835 (4)146
C12—H12A···Cg1i0.972.543.282 (5)133
Symmetry codes: (i) x, y−1, z.
Acknowledgements top

The authors acknowledge the Faculty of Arts and Sciences, Ondokuz Mayıs University, Turkey, for the use of the Stoe IPDS 2 diffractometer (purchased under grant F.279 of the University Research Fund).

references
References top

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