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ISSN: 2056-9890

4-Chloro-N′-[(3Z)-2-oxo-2,3-di­hydro-1H-indol-3-yl­­idene]benzohydrazide

aChemistry and Environmental Division, Manchester Metropolitan University, Manchester M1 5GD, England, bChemistry Department, Faculty of Science, Minia University, 61519 El-Minia, Egypt, cDepartment of Chemistry, Tulane University, New Orleans, LA 70118, USA, dDepartment of Physics, Faculty of Sciences, Erciyes University, 38039 Kayseri, Turkey, eChemistry Department, Faculty of Science, Assiut University, Assiut, Egypt, and fKirkuk University, College of Science, Department of Chemistry, Kirkuk, Iraq
*Correspondence e-mail: shaabankamel@yahoo.com

(Received 5 December 2013; accepted 9 December 2013; online 14 December 2013)

In the title compound, C15H10ClN3O2, the benzene ring is slightly twisted out of the plane of the 2,3-di­hydro-1H-indole ring system (r.m.s. deviation = 0.007 Å), forming a dihedral angle of 7.4 (3)°. An intra­molecular N—H⋯O hydrogen bond forms a six-membered ring. In the crystal, mol­ecules are linked via N—H⋯O and C—H⋯O hydrogen bonds, forming layers alternately perpendicular to [011] and [0-11].

Related literature

For the diverse bio-activities of acid hydrazides and their condensed products, see: Adekunle et al. (2012[Adekunle, F. A. O., Woods, J. A. O. & Odunola, O. A. (2012). Res. J. Pharm. Bio. Chem. Sci., 3, 1120-1127.]); Al-Assar et al. (2002[Al-Assar, F., Zelenin, K. N., Lesiovskaya, E. E., Bezant, I. P. & Chakchir, B. A. (2002). Pharm. Chem. J. 36, 598-603.]); Dharmaraj et al. (2001[Dharmaraj, N., Viswanalhamurthi, P. & Natarajan, K. (2001). Transition Met. Chem. 26, 105-118.]); Jain & Vederas (2004[Jain, R. P. & Vederas, J. C. (2004). Bioorg. Med. Chem. Lett. 14, 3655-3658.]); Jeeworth et al. (2000[Jeeworth, T., Wah, H. L. K., Bhowon, M. G., Ghoorhoo, D. & Babooram, K. (2000). Synth. React. Inorg. Met. Org. Chem. 30, 1023-1038.]); Scozzafava et al. (2001[Scozzafava, A., Menabuoni, L., Mincione, F., Mincione, G. & Supuran, C. T. (2001). Bioorg. Med. Chem. Lett. 11, 575-582.]); Siddappa et al. (2008[Siddappa, K., Reddy, T., Mallikarjun, M. & Reddy, C. V. (2008). Eur. J. Chem. 5, 155-162.]); Strappaghetti et al. (2006[Strappaghetti, G., Brodi, C., Giannaccini, G. & Betti, L. (2006). Bioorg. Med. Chem. Lett. 16, 2575-2579.]).

[Scheme 1]

Experimental

Crystal data
  • C15H10ClN3O2

  • Mr = 299.71

  • Orthorhombic, P c a 21

  • a = 31.0359 (12) Å

  • b = 5.2549 (3) Å

  • c = 7.8730 (4) Å

  • V = 1284.01 (11) Å3

  • Z = 4

  • Cu Kα radiation

  • μ = 2.72 mm−1

  • T = 102 K

  • 0.22 × 0.17 × 0.01 mm

Data collection
  • Bruker D8 VENTURE PHOTON 100 CMOS diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2013[Bruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.75, Tmax = 0.97

  • 4190 measured reflections

  • 1596 independent reflections

  • 1434 reflections with I > 2σ(I)

  • Rint = 0.109

Refinement
  • R[F2 > 2σ(F2)] = 0.059

  • wR(F2) = 0.152

  • S = 1.16

  • 1596 reflections

  • 193 parameters

  • 3 restraints

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.30 e Å−3

  • Δρmin = −0.37 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 478 Friedal pairs (44% coverage)

  • Absolute structure parameter: −0.06 (5)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯O2 0.90 (5) 1.87 (6) 2.685 (9) 151 (4)
N3—H3A⋯O1i 0.91 1.98 2.798 (8) 149
C11—H11⋯O1i 0.95 2.55 3.218 (10) 128
C14—H14⋯O2ii 0.95 2.29 3.233 (9) 172
Symmetry codes: (i) [-x+{\script{1\over 2}}, y-1, z-{\script{1\over 2}}]; (ii) [-x+{\script{1\over 2}}, y+1, z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2013[Bruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2013[Bruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]); software used to prepare material for publication: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

Hydrazide compounds and their condensation products exhibit a wide range of biological activities such as anti-cancer (Strappaghetti et al., 2006), anti-depressant (Al-Assar et al., 2002), anti-HIV (Adekunle et al., 2012), analgesic-anti-inflammatory (Jain & Vederas, 2004), bactericidal (Jeeworth et al., 2000), leishmanicidal (Scozzafava et al., 2001), anti-helmintic (Dharmaraj et al., 2001) and anti-tuberculosis activities (Siddappa et al., 2008). Based on such findings and continuing to our on-going study of the synthesis of bio-active heterocyclic compounds, we herein report on the synthesis and crystal structure of the title compound.

In the title compound, Fig. 1, the intramolecular N1—H1···O2 hydrogen bond forms a pseudo-six-membered ring. The nine non-H ring atoms of the fused five- and six-membered ring system are almost coplanar (r.m.s. deviation = 0.007 Å). The benzene ring and the 2,3-dihydro-1H-indole ring system make a dihedral angle of 7.4 (3)° .

In the crystal structure, molecular layers formed by N—H···O and C-H···O hydrogen bonds are alternately perpendicular to [011] and to [0–11] directions (Table 1 and Fig. 2).

Related literature top

For the diverse bio-activities of acid hydrazides and their condensed products, see: Adekunle et al. (2012); Al-Assar et al. (2002); Dharmaraj et al. (2001); Jain & Vederas (2004); Jeeworth et al. (2000); Scozzafava et al. (2001); Siddappa et al. (2008); Strappaghetti et al. (2006).

Experimental top

A mixture of 1 mmol (170.6 mg) 4-chlorobenzohydrazidean and 1 mmol (147 mg) 1H-indole-2,3-dione in 25 ml ethanol with few drops of glacial acetic acid was refluxed for 5h. The solid formed was collected and recrystallized from DMF to furnish the title compound as yellow crystals suitable for X-ray analysis [M.p. 558 K].

Refinement top

The NH H atoms (H1 on N1) was located in a difference Fourier map and refined with a distance restraint: N1—H1 = 0.90 (5) Å with Uiso(H) = 1.2Ueq(N). The remaining H atoms were placed in calculated positions and refined using a riding model approximation: C—H = 0.95 Å and N—H = 0.91 Å with Uiso(H) = 1.2Ueq(C, N). The small proportion of reflections observed is a result of the rather poor quality of the very thin crystals obtained.

Structure description top

Hydrazide compounds and their condensation products exhibit a wide range of biological activities such as anti-cancer (Strappaghetti et al., 2006), anti-depressant (Al-Assar et al., 2002), anti-HIV (Adekunle et al., 2012), analgesic-anti-inflammatory (Jain & Vederas, 2004), bactericidal (Jeeworth et al., 2000), leishmanicidal (Scozzafava et al., 2001), anti-helmintic (Dharmaraj et al., 2001) and anti-tuberculosis activities (Siddappa et al., 2008). Based on such findings and continuing to our on-going study of the synthesis of bio-active heterocyclic compounds, we herein report on the synthesis and crystal structure of the title compound.

In the title compound, Fig. 1, the intramolecular N1—H1···O2 hydrogen bond forms a pseudo-six-membered ring. The nine non-H ring atoms of the fused five- and six-membered ring system are almost coplanar (r.m.s. deviation = 0.007 Å). The benzene ring and the 2,3-dihydro-1H-indole ring system make a dihedral angle of 7.4 (3)° .

In the crystal structure, molecular layers formed by N—H···O and C-H···O hydrogen bonds are alternately perpendicular to [011] and to [0–11] directions (Table 1 and Fig. 2).

For the diverse bio-activities of acid hydrazides and their condensed products, see: Adekunle et al. (2012); Al-Assar et al. (2002); Dharmaraj et al. (2001); Jain & Vederas (2004); Jeeworth et al. (2000); Scozzafava et al. (2001); Siddappa et al. (2008); Strappaghetti et al. (2006).

Computing details top

Data collection: APEX2 (Bruker, 2013); cell refinement: SAINT (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title molecule, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level. The intramolecular N-H···O hydrogen bond is shown as a dashed line (see Table 1 for details).
[Figure 2] Fig. 2. A view along the b axis of the crystal packing of the title compound. The hydrogen bonds are shown as a dashed lines (see Table 1 for details).
4-Chloro-N'-[(3Z)-2-oxo-2,3-dihydro-1H-indol-3-ylidene]benzohydrazide top
Crystal data top
C15H10ClN3O2F(000) = 616
Mr = 299.71Dx = 1.550 Mg m3
Orthorhombic, Pca21Cu Kα radiation, λ = 1.54178 Å
Hall symbol: P 2c -2acCell parameters from 3290 reflections
a = 31.0359 (12) Åθ = 2.9–68.5°
b = 5.2549 (3) ŵ = 2.72 mm1
c = 7.8730 (4) ÅT = 102 K
V = 1284.01 (11) Å3Plate, yellow
Z = 40.22 × 0.17 × 0.01 mm
Data collection top
Bruker D8 VENTURE PHOTON 100 CMOS
diffractometer
1596 independent reflections
Radiation source: INCOATEC IµS micro–focus source1434 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.109
Detector resolution: 10.4167 pixels mm-1θmax = 68.5°, θmin = 5.7°
ω scansh = 3237
Absorption correction: multi-scan
(SADABS; Bruker, 2013)
k = 55
Tmin = 0.75, Tmax = 0.97l = 89
4190 measured reflections
Refinement top
Refinement on F2Secondary atom site location: inferred from neighbouring sites
Least-squares matrix: fullH atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.059 W = 1/[Σ2(Fo2) + (0.0459P)2 + 3.7436P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.152(Δ/σ)max < 0.001
S = 1.16Δρmax = 0.30 e Å3
1596 reflectionsΔρmin = 0.37 e Å3
193 parametersAbsolute structure: Flack (1983), 478 Friedal pairs (44% coverage)
3 restraintsAbsolute structure parameter: 0.06 (5)
Primary atom site location: difference Fourier map
Crystal data top
C15H10ClN3O2V = 1284.01 (11) Å3
Mr = 299.71Z = 4
Orthorhombic, Pca21Cu Kα radiation
a = 31.0359 (12) ŵ = 2.72 mm1
b = 5.2549 (3) ÅT = 102 K
c = 7.8730 (4) Å0.22 × 0.17 × 0.01 mm
Data collection top
Bruker D8 VENTURE PHOTON 100 CMOS
diffractometer
1596 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2013)
1434 reflections with I > 2σ(I)
Tmin = 0.75, Tmax = 0.97Rint = 0.109
4190 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.059H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.152Δρmax = 0.30 e Å3
S = 1.16Δρmin = 0.37 e Å3
1596 reflectionsAbsolute structure: Flack (1983), 478 Friedal pairs (44% coverage)
193 parametersAbsolute structure parameter: 0.06 (5)
3 restraints
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
Cl10.02432 (5)0.0784 (4)0.5130 (3)0.0317 (6)
O10.15220 (15)0.7554 (12)0.7066 (7)0.0247 (19)
O20.21783 (16)0.0289 (11)0.3951 (7)0.0240 (19)
N10.18451 (17)0.4151 (14)0.5756 (8)0.0187 (19)
N20.22478 (17)0.5046 (12)0.6135 (8)0.0173 (19)
N30.29242 (19)0.0513 (13)0.4056 (8)0.0203 (19)
C10.0263 (2)0.2224 (17)0.5393 (10)0.026 (3)
C20.0616 (2)0.1072 (16)0.4604 (10)0.023 (2)
C30.1021 (2)0.2172 (17)0.4862 (10)0.026 (3)
C40.1069 (2)0.4273 (16)0.5882 (9)0.020 (2)
C50.0705 (2)0.5395 (17)0.6625 (10)0.026 (3)
C60.0301 (2)0.4340 (18)0.6391 (11)0.028 (3)
C70.1495 (2)0.5554 (18)0.6291 (10)0.024 (3)
C80.2560 (2)0.3623 (15)0.5494 (9)0.018 (2)
C90.2517 (2)0.1344 (16)0.4425 (10)0.022 (2)
C100.3234 (2)0.2196 (15)0.4808 (9)0.018 (2)
C110.3677 (2)0.2028 (16)0.4744 (10)0.022 (2)
C120.3910 (2)0.3895 (16)0.5590 (10)0.025 (3)
C130.3700 (2)0.5837 (17)0.6480 (10)0.025 (3)
C140.3253 (2)0.5978 (15)0.6566 (9)0.019 (3)
C150.3018 (2)0.4074 (16)0.5723 (9)0.021 (3)
H10.1866 (10)0.264 (9)0.523 (10)0.0220*
H20.058200.040300.391900.0280*
H30.126600.145500.432400.0310*
H3A0.300900.061300.324400.0250*
H50.073700.688800.729400.0320*
H60.005500.507300.691400.0340*
H110.381600.069200.414700.0270*
H120.421600.385300.556400.0290*
H130.386700.709500.704100.0300*
H140.311300.730600.717100.0230*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.0189 (8)0.0414 (13)0.0349 (11)0.0052 (7)0.0031 (9)0.0024 (11)
O10.022 (3)0.030 (4)0.022 (3)0.004 (2)0.001 (2)0.009 (3)
O20.023 (3)0.030 (4)0.019 (3)0.002 (2)0.001 (2)0.007 (3)
N10.015 (3)0.024 (4)0.017 (3)0.003 (2)0.002 (2)0.006 (3)
N20.019 (3)0.021 (4)0.012 (3)0.000 (2)0.002 (2)0.000 (3)
N30.020 (3)0.024 (4)0.017 (3)0.001 (3)0.001 (3)0.007 (3)
C10.020 (3)0.040 (6)0.019 (4)0.006 (3)0.008 (3)0.009 (4)
C20.023 (3)0.023 (5)0.024 (4)0.003 (3)0.004 (3)0.006 (4)
C30.026 (4)0.033 (5)0.019 (4)0.001 (3)0.002 (4)0.005 (4)
C40.025 (4)0.025 (5)0.010 (3)0.004 (3)0.003 (3)0.002 (3)
C50.022 (4)0.039 (6)0.018 (4)0.003 (3)0.001 (3)0.005 (4)
C60.021 (4)0.040 (6)0.023 (4)0.007 (3)0.005 (3)0.001 (4)
C70.022 (4)0.036 (6)0.015 (4)0.006 (3)0.001 (3)0.003 (4)
C80.025 (3)0.019 (5)0.009 (4)0.002 (3)0.005 (3)0.002 (3)
C90.013 (3)0.038 (5)0.016 (4)0.001 (3)0.002 (3)0.005 (4)
C100.017 (3)0.025 (5)0.013 (4)0.000 (3)0.003 (3)0.004 (3)
C110.025 (3)0.022 (5)0.020 (4)0.006 (3)0.000 (3)0.004 (4)
C120.017 (3)0.034 (6)0.023 (5)0.002 (3)0.000 (3)0.003 (4)
C130.022 (4)0.034 (6)0.018 (4)0.001 (3)0.001 (3)0.001 (4)
C140.026 (4)0.016 (5)0.016 (4)0.000 (3)0.001 (3)0.001 (3)
C150.024 (4)0.022 (5)0.018 (4)0.002 (3)0.001 (3)0.001 (3)
Geometric parameters (Å, º) top
Cl1—C11.756 (7)C8—C91.470 (11)
O1—C71.218 (11)C8—C151.452 (9)
O2—C91.246 (9)C10—C151.394 (11)
N1—N21.368 (8)C10—C111.379 (9)
N1—C71.379 (10)C11—C121.389 (11)
N2—C81.324 (9)C12—C131.399 (11)
N3—C91.368 (9)C13—C141.391 (9)
N3—C101.434 (9)C14—C151.405 (11)
N1—H10.90 (5)C2—H20.9500
N3—H3A0.9100C3—H30.9500
C1—C61.367 (13)C5—H50.9500
C1—C21.397 (10)C6—H60.9500
C2—C31.398 (10)C11—H110.9500
C3—C41.373 (12)C12—H120.9500
C4—C51.402 (10)C13—H130.9500
C4—C71.518 (10)C14—H140.9500
C5—C61.383 (10)
N2—N1—C7118.0 (7)N3—C10—C15109.1 (6)
N1—N2—C8113.0 (6)C11—C10—C15123.0 (7)
C9—N3—C10109.6 (6)N3—C10—C11127.9 (7)
C7—N1—H1132 (2)C10—C11—C12117.2 (7)
N2—N1—H1110 (2)C11—C12—C13120.9 (6)
C9—N3—H3A129.00C12—C13—C14121.9 (7)
C10—N3—H3A120.00C13—C14—C15117.2 (7)
Cl1—C1—C6119.7 (5)C8—C15—C14133.1 (7)
C2—C1—C6122.7 (6)C10—C15—C14119.9 (6)
Cl1—C1—C2117.5 (6)C8—C15—C10106.9 (6)
C1—C2—C3117.5 (7)C1—C2—H2121.00
C2—C3—C4121.0 (7)C3—C2—H2121.00
C3—C4—C5119.6 (6)C2—C3—H3119.00
C3—C4—C7125.1 (6)C4—C3—H3120.00
C5—C4—C7115.3 (7)C4—C5—H5120.00
C4—C5—C6120.4 (8)C6—C5—H5120.00
C1—C6—C5118.7 (7)C1—C6—H6121.00
O1—C7—C4123.3 (6)C5—C6—H6121.00
N1—C7—C4112.6 (7)C10—C11—H11121.00
O1—C7—N1124.1 (6)C12—C11—H11122.00
N2—C8—C9127.7 (6)C11—C12—H12120.00
N2—C8—C15125.2 (7)C13—C12—H12120.00
C9—C8—C15107.0 (6)C12—C13—H13119.00
N3—C9—C8107.3 (6)C14—C13—H13119.00
O2—C9—N3125.0 (7)C13—C14—H14121.00
O2—C9—C8127.7 (6)C15—C14—H14122.00
C7—N1—N2—C8177.0 (7)C5—C4—C7—N1170.3 (7)
N2—N1—C7—O10.7 (12)C4—C5—C6—C11.5 (13)
N2—N1—C7—C4176.6 (6)N2—C8—C9—O21.7 (14)
N1—N2—C8—C92.1 (11)N2—C8—C9—N3179.7 (7)
N1—N2—C8—C15178.5 (7)C15—C8—C9—O2178.8 (8)
C10—N3—C9—O2179.9 (7)C15—C8—C9—N30.1 (8)
C10—N3—C9—C81.4 (8)N2—C8—C15—C10178.3 (7)
C9—N3—C10—C11179.7 (8)N2—C8—C15—C141.6 (14)
C9—N3—C10—C152.2 (9)C9—C8—C15—C101.2 (8)
Cl1—C1—C2—C3177.9 (6)C9—C8—C15—C14177.9 (8)
C6—C1—C2—C30.2 (12)N3—C10—C11—C12179.6 (7)
Cl1—C1—C6—C5177.9 (7)C15—C10—C11—C122.4 (12)
C2—C1—C6—C50.3 (13)N3—C10—C15—C82.1 (8)
C1—C2—C3—C41.3 (12)N3—C10—C15—C14179.3 (7)
C2—C3—C4—C52.5 (12)C11—C10—C15—C8179.7 (7)
C2—C3—C4—C7177.8 (8)C11—C10—C15—C143.1 (12)
C3—C4—C5—C62.6 (12)C10—C11—C12—C130.7 (12)
C7—C4—C5—C6177.7 (8)C11—C12—C13—C140.4 (12)
C3—C4—C7—O1172.7 (8)C12—C13—C14—C150.2 (12)
C3—C4—C7—N110.0 (11)C13—C14—C15—C8178.2 (8)
C5—C4—C7—O17.0 (12)C13—C14—C15—C101.9 (11)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O20.90 (5)1.87 (6)2.685 (9)151 (4)
N3—H3A···O1i0.911.982.798 (8)149
C11—H11···O1i0.952.553.218 (10)128
C14—H14···O2ii0.952.293.233 (9)172
Symmetry codes: (i) x+1/2, y1, z1/2; (ii) x+1/2, y+1, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O20.90 (5)1.87 (6)2.685 (9)151 (4)
N3—H3A···O1i0.911.982.798 (8)149
C11—H11···O1i0.952.553.218 (10)128
C14—H14···O2ii0.952.293.233 (9)172
Symmetry codes: (i) x+1/2, y1, z1/2; (ii) x+1/2, y+1, z+1/2.
 

Acknowledgements

Manchester Metropolitan University, Tulane University and Erciyes University are gratefully acknowledged for supporting this study. The support of NSF–MRI grant No. 1228232 for the purchase of the diffractometer is also gratefully acknowledged.

References

First citationAdekunle, F. A. O., Woods, J. A. O. & Odunola, O. A. (2012). Res. J. Pharm. Bio. Chem. Sci., 3, 1120-1127.  CAS Google Scholar
First citationAl-Assar, F., Zelenin, K. N., Lesiovskaya, E. E., Bezant, I. P. & Chakchir, B. A. (2002). Pharm. Chem. J. 36, 598–603.  CAS Google Scholar
First citationBruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationDharmaraj, N., Viswanalhamurthi, P. & Natarajan, K. (2001). Transition Met. Chem. 26, 105–118.  Web of Science CrossRef CAS Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationFlack, H. D. (1983). Acta Cryst. A39, 876–881.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationJain, R. P. & Vederas, J. C. (2004). Bioorg. Med. Chem. Lett. 14, 3655–3658.  Web of Science CrossRef PubMed CAS Google Scholar
First citationJeeworth, T., Wah, H. L. K., Bhowon, M. G., Ghoorhoo, D. & Babooram, K. (2000). Synth. React. Inorg. Met. Org. Chem. 30, 1023–1038.  Google Scholar
First citationScozzafava, A., Menabuoni, L., Mincione, F., Mincione, G. & Supuran, C. T. (2001). Bioorg. Med. Chem. Lett. 11, 575–582.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSiddappa, K., Reddy, T., Mallikarjun, M. & Reddy, C. V. (2008). Eur. J. Chem. 5, 155–162.  Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationStrappaghetti, G., Brodi, C., Giannaccini, G. & Betti, L. (2006). Bioorg. Med. Chem. Lett. 16, 2575–2579.  Web of Science CrossRef PubMed CAS Google Scholar

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