supplementary materials


HTML versionpdf versioncif file3d viewstructure factorssupplementary materialsCIF check reportcited insimilar papers Open access

is2386 scheme

Acta Cryst. (2009). E65, o445    [ doi:10.1107/S1600536809003420 ]

2-(4-Isobutylphenyl)-N'-[1-(4-nitrophenyl)ethylidene]propanohydrazide

H.-K. Fun, S. Chantrapromma, K. V. Sujith and B. Kalluraya

Abstract top

The molecule of the title compound, C21H25N3O3, exists in a trans configuration with respect to the ethylidene unit. The dihedral angle between the two substituted benzene rings is 86.99 (7)°. The nitro group is twisted from the attached benzene ring at an angle of 17.02 (7)°. In the crystal structure, molecules are linked by pairs of N-H...O hydrogen bonds in a face-to-face manner into centrosymmetric dimers. These dimer units are further linked into chains along the c axis by weak C-H...O interactions. These chains are stacked along the b axis. The crystal is further stabilized by weak C-H...[pi] interactions.

Comment top

Hydrazones have been prepared by treating aryl hydrazines with carbonyl compounds using a variety of solvents in presence or absence of an acidic catalyst. (Pasha & Nanjundaswamy, 2004). Aryl hydrazones are important building blocks for the synthesis of a variety of heterocyclic compounds such as pyrazolines and pyrazoles (Sridhar & Perumal, 2003). Hydrazones have been demonstrated to possess variety of pharmacological activities (Bedia et al., 2006; Rollas et al., 2002; Terzioglu & Gürsoy, 2003). These observations have been the guidelines for the development of new hydrazones that possess varied biological activities. Similarly ibuprofen is also known for their pharmaceutical activities and belongs to the class of non-steroidal anti-inflammatory drugs (Amir & Kumar, 2007). According to our previous work, we are interested in the synthesis and crystal structure of ibuprofen containing hydrazone derivatives (Fun et al., 2008). Prompted by the biological activities of hydrazones and ibuprofen, the title compound was synthesized and it crystal structure was reported here.

In the structure of the title compound, (I), the molecule exist in a trans configuration with respect to the ethylidene C9═N2 unit (Fig. 1). The dihedral angle between the two substituted benzene rings is 86.99 (7)°. In the 4-nitrophenyl unit, the nitro group is twisted from the mean plane of the C10–C15 ring which can be shown by the dihedral angle between the mean planes through the C13/N3/O2/O3 group and the C10–C15 ring being 17.02 (7)°. Atoms O1, N1, N2, C7, C8, C9 and C21 lie on the same plane with a maximum deviation of -0.032 (1)Å for atom N1. This plane makes dihedral angles of 73.01 (6) and 15.02 (5)° with the C1–C6 and C10–C15 benzene rings, respectively. The isobutyl substituent (C16–C19) is (-)-synclinal with respect to the C1–C6 ring with the torsion angle C2—C3—C16—C17 being -76.91 (14)°. The bond distances have normal values (Allen et al., 1987) and are comparable with the related structure (Fun et al., 2008).

In the crystal packing, N—H···O hydrogen bonds (Table 1 and Fig. 2) link the molecules into face-to-face dimers. These dimers are further linked into chains along the c axis and these chains are stacked along the b axis. The crystal is stabilized by N—H···O hydrogen bonding, and weak C—H···O and C—H···π interactions (Table 1); Cg1 and Cg2 are the centroids of the C1–C6 and C10–C15 rings, respectively (Table 1).

Related literature top

For values of bond lengths, see: Allen et al. (1987). For related structures, see, for example: Fun et al. (2008). For background to the activities and applications of hydrazones, see, for example: Amir & Kumar (2007); Bedia et al. (2006); Pasha & Nanjundaswamy (2004); Rollas et al. (2002); Sridhar & Perumal (2003); Terzioglu & Gürsoy (2003). Cg1 and Cg2 are the centroids of the C1–C6 and C10–C15 rings, respectively.

Experimental top

The title compound was obtained by refluxing 2-[4-(2-methylpropyl)phenyl]propanehydrazide (0.01 mol) and 4-nitroacetophenone (0.01 mol) in ethanol (30 ml) by adding 3 drops of concentrated Sulfuric acid for 1 h. Excess ethanol was removed from the reaction mixture under reduced pressure. The solid product obtained was filtered, washed with ethanol and dried. Colorless single crystals suitable for X-ray analysis were obtained from ethanol by slow evaporation (yield 74%; m.p. 443 K).

Refinement top

All H atoms were placed in calculated positions with d(N—H) = 0.89 Å, Uiso(H) = 1.2Ueq(N) for NH, d(C—H) = 0.93 Å, Uiso(H) = 1.2Ueq(C) for aromatic and CH, 0.97 Å, Uiso(H) = 1.2Ueq(C) for CH2, 0.96 Å, Uiso(H) = 1.5Ueq(C) for CH3 atoms. The rotating group model was used for the methyl groups. The highest residual electron density peak is located at 0.65 Å from C10 and the deepest hole is located at 1.29 Å from C9.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: SAINT (Bruker, 2005); 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, 2003).

Figures top
[Figure 1] Fig. 1. The structure of (I), showing 50% probability displacement ellipsoids and the atom-numbering scheme.
[Figure 2] Fig. 2. The packing diagram of (I), viewed along the b axis, showing dimers linked by C—H···O interactions into a chain along the c axis. Hydrogen bonds and weak interactions are shown as dashed lines.
2-(4-Isobutylphenyl)-N'-[1-(4-nitrophenyl)ethylidene]propanohydrazide top
Crystal data top
C21H25N3O3F(000) = 784
Mr = 367.44Dx = 1.282 Mg m−3
Monoclinic, P21/cMelting point: 443 K
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 13.7343 (2) ÅCell parameters from 5560 reflections
b = 7.9039 (2) Åθ = 2.0–30.0°
c = 20.8408 (3) ŵ = 0.09 mm−1
β = 122.677 (1)°T = 100 K
V = 1904.29 (7) Å3Block, colorless
Z = 40.58 × 0.20 × 0.10 mm
Data collection top
Bruker SMART APEX2 CCD area-detector
diffractometer		5506 independent reflections
Radiation source: fine-focus sealed tube4402 reflections with I > 2σ(I)
graphiteRint = 0.041
Detector resolution: 8.33 pixels mm-1θmax = 30.0°, θmin = 2.0°
ω scansh = −19→19
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		k = −10→11
Tmin = 0.952, Tmax = 0.991l = −29→29
24946 measured reflections
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)] = 0.046Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.122H-atom parameters constrained
S = 1.05 w = 1/[σ2(Fo2) + (0.0567P)2 + 0.5875P]
where P = (Fo2 + 2Fc2)/3
5506 reflections(Δ/σ)max = 0.001
248 parametersΔρmax = 0.37 e Å−3
0 restraintsΔρmin = −0.28 e Å−3
Crystal data top
C21H25N3O3V = 1904.29 (7) Å3
Mr = 367.44Z = 4
Monoclinic, P21/cMo Kα radiation
a = 13.7343 (2) ŵ = 0.09 mm−1
b = 7.9039 (2) ÅT = 100 K
c = 20.8408 (3) Å0.58 × 0.20 × 0.10 mm
β = 122.677 (1)°
Data collection top
Bruker SMART APEX2 CCD area-detector
diffractometer		5506 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)		4402 reflections with I > 2σ(I)
Tmin = 0.952, Tmax = 0.991Rint = 0.041
24946 measured reflectionsθmax = 30.0°
Refinement top
R[F2 > 2σ(F2)] = 0.046H-atom parameters constrained
wR(F2) = 0.122Δρmax = 0.37 e Å−3
S = 1.05Δρmin = −0.28 e Å−3
5506 reflectionsAbsolute structure: ?
248 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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
O10.61564 (7)1.53156 (12)0.98872 (5)0.02087 (19)
O20.39321 (8)0.36757 (13)0.73982 (5)0.0250 (2)
O30.25151 (8)0.31704 (13)0.75538 (6)0.0285 (2)
N10.50374 (8)1.30105 (14)0.94275 (6)0.0169 (2)
H10.46871.33500.96610.020*
N20.47995 (8)1.14801 (14)0.90567 (5)0.0162 (2)
N30.32794 (9)0.40891 (14)0.76090 (6)0.0200 (2)
C10.74608 (10)1.05444 (16)0.93547 (7)0.0173 (2)
H1A0.68381.02280.88770.021*
C20.83450 (10)0.93944 (16)0.97821 (7)0.0184 (2)
H2A0.83100.83280.95820.022*
C30.92861 (10)0.98084 (16)1.05069 (7)0.0176 (2)
C40.93176 (10)1.14328 (17)1.07810 (7)0.0195 (2)
H4A0.99371.17451.12600.023*
C50.84359 (10)1.25954 (17)1.03485 (7)0.0180 (2)
H5A0.84791.36721.05420.022*
C60.74891 (10)1.21660 (16)0.96282 (6)0.0158 (2)
C70.65444 (10)1.34418 (16)0.91325 (7)0.0168 (2)
H7A0.59831.28920.86490.020*
C80.59144 (10)1.40054 (16)0.95135 (6)0.0162 (2)
C90.39775 (9)1.05845 (16)0.90156 (6)0.0159 (2)
C100.37649 (10)0.89227 (16)0.86281 (6)0.0158 (2)
C110.42259 (10)0.85604 (17)0.81818 (7)0.0188 (2)
H11A0.46380.93910.81100.023*
C120.40751 (10)0.69891 (17)0.78498 (7)0.0193 (2)
H12A0.43950.67500.75640.023*
C130.34376 (10)0.57704 (16)0.79498 (6)0.0173 (2)
C140.29521 (10)0.60950 (17)0.83742 (7)0.0187 (2)
H14A0.25210.52720.84310.022*
C150.31236 (10)0.76689 (17)0.87100 (7)0.0185 (2)
H15A0.28040.78970.89970.022*
C161.02083 (10)0.85055 (17)1.09705 (7)0.0202 (2)
H16A1.08980.90781.13680.024*
H16B1.04050.79351.06430.024*
C170.98418 (10)0.71672 (17)1.13418 (7)0.0184 (2)
H17A0.90730.67481.09510.022*
C181.06782 (11)0.56769 (18)1.16314 (8)0.0241 (3)
H18A1.04530.48711.18730.036*
H18B1.14470.60731.19930.036*
H18C1.06610.51481.12110.036*
C190.97652 (11)0.7941 (2)1.19870 (7)0.0249 (3)
H19A0.94540.71211.21690.037*
H19B0.92700.89161.18000.037*
H19C1.05240.82711.23970.037*
C200.70381 (11)1.49872 (18)0.89582 (8)0.0226 (3)
H20A0.73841.46340.86850.034*
H20B0.76131.55190.94270.034*
H20C0.64271.57760.86540.034*
C210.32900 (10)1.11330 (18)0.93465 (7)0.0203 (3)
H21A0.29331.22060.91340.030*
H21B0.37941.12360.98900.030*
H21C0.27031.03070.92270.030*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0209 (4)0.0185 (5)0.0261 (4)−0.0017 (4)0.0145 (4)−0.0043 (4)
O20.0296 (5)0.0246 (5)0.0256 (4)0.0039 (4)0.0180 (4)−0.0002 (4)
O30.0281 (5)0.0212 (5)0.0368 (5)−0.0066 (4)0.0178 (4)−0.0043 (4)
N10.0166 (4)0.0165 (5)0.0205 (5)0.0000 (4)0.0119 (4)−0.0017 (4)
N20.0159 (4)0.0148 (5)0.0172 (4)0.0005 (4)0.0085 (4)0.0000 (4)
N30.0211 (5)0.0181 (5)0.0180 (5)0.0016 (4)0.0088 (4)0.0020 (4)
C10.0178 (5)0.0173 (6)0.0187 (5)−0.0028 (5)0.0110 (4)−0.0025 (5)
C20.0221 (6)0.0140 (6)0.0243 (6)−0.0011 (5)0.0159 (5)−0.0013 (5)
C30.0171 (5)0.0164 (6)0.0240 (5)−0.0009 (5)0.0142 (5)0.0017 (5)
C40.0164 (5)0.0205 (7)0.0209 (5)−0.0024 (5)0.0097 (5)−0.0013 (5)
C50.0183 (5)0.0157 (6)0.0216 (5)−0.0011 (5)0.0117 (5)−0.0023 (5)
C60.0152 (5)0.0164 (6)0.0196 (5)−0.0007 (5)0.0119 (4)0.0003 (5)
C70.0165 (5)0.0179 (6)0.0182 (5)0.0005 (5)0.0109 (4)0.0002 (5)
C80.0144 (5)0.0172 (6)0.0161 (5)0.0022 (5)0.0076 (4)0.0021 (5)
C90.0132 (5)0.0187 (6)0.0151 (5)0.0025 (5)0.0071 (4)0.0022 (4)
C100.0132 (5)0.0177 (6)0.0150 (5)0.0016 (5)0.0066 (4)0.0018 (4)
C110.0185 (5)0.0210 (6)0.0197 (5)−0.0026 (5)0.0122 (5)0.0003 (5)
C120.0194 (5)0.0223 (6)0.0180 (5)−0.0009 (5)0.0112 (5)−0.0008 (5)
C130.0159 (5)0.0172 (6)0.0158 (5)0.0011 (5)0.0066 (4)0.0001 (5)
C140.0168 (5)0.0189 (6)0.0208 (5)−0.0004 (5)0.0104 (5)0.0029 (5)
C150.0165 (5)0.0216 (6)0.0192 (5)0.0010 (5)0.0109 (4)0.0013 (5)
C160.0174 (5)0.0192 (6)0.0269 (6)0.0016 (5)0.0140 (5)0.0027 (5)
C170.0163 (5)0.0188 (6)0.0202 (5)−0.0007 (5)0.0100 (4)0.0007 (5)
C180.0240 (6)0.0213 (7)0.0270 (6)0.0026 (6)0.0136 (5)0.0043 (5)
C190.0217 (6)0.0319 (8)0.0221 (6)0.0016 (6)0.0125 (5)0.0005 (6)
C200.0229 (6)0.0221 (7)0.0271 (6)0.0002 (5)0.0162 (5)0.0036 (5)
C210.0183 (5)0.0209 (6)0.0263 (6)−0.0006 (5)0.0150 (5)−0.0014 (5)
Geometric parameters (Å, °) top
O1—C81.2288 (15)C11—C121.3819 (18)
O2—N31.2364 (13)C11—H11A0.9300
O3—N31.2297 (14)C12—C131.3910 (17)
N1—C81.3668 (15)C12—H12A0.9300
N1—N21.3764 (15)C13—C141.3892 (16)
N1—H10.8906C14—C151.3837 (18)
N2—C91.2956 (15)C14—H14A0.9300
N3—C131.4667 (17)C15—H15A0.9300
C1—C21.3879 (18)C16—C171.5465 (17)
C1—C61.3947 (17)C16—H16A0.9700
C1—H1A0.9300C16—H16B0.9700
C2—C31.3969 (17)C17—C181.5241 (18)
C2—H2A0.9300C17—C191.5315 (17)
C3—C41.3964 (18)C17—H17A0.9800
C3—C161.5089 (17)C18—H18A0.9600
C4—C51.3945 (18)C18—H18B0.9600
C4—H4A0.9300C18—H18C0.9600
C5—C61.3971 (17)C19—H19A0.9600
C5—H5A0.9300C19—H19B0.9600
C6—C71.5232 (17)C19—H19C0.9600
C7—C81.5231 (15)C20—H20A0.9600
C7—C201.5328 (18)C20—H20B0.9600
C7—H7A0.9800C20—H20C0.9600
C9—C101.4860 (18)C21—H21A0.9600
C9—C211.5027 (15)C21—H21B0.9600
C10—C151.3962 (17)C21—H21C0.9600
C10—C111.4083 (15)
C8—N1—N2120.30 (9)C14—C13—C12121.66 (12)
C8—N1—H1116.9C14—C13—N3118.64 (11)
N2—N1—H1122.5C12—C13—N3119.70 (10)
C9—N2—N1116.84 (10)C15—C14—C13118.61 (11)
O3—N3—O2123.84 (12)C15—C14—H14A120.7
O3—N3—C13118.43 (10)C13—C14—H14A120.7
O2—N3—C13117.73 (10)C14—C15—C10121.51 (10)
C2—C1—C6121.19 (11)C14—C15—H15A119.2
C2—C1—H1A119.4C10—C15—H15A119.2
C6—C1—H1A119.4C3—C16—C17113.56 (10)
C1—C2—C3121.25 (12)C3—C16—H16A108.9
C1—C2—H2A119.4C17—C16—H16A108.9
C3—C2—H2A119.4C3—C16—H16B108.9
C4—C3—C2117.64 (11)C17—C16—H16B108.9
C4—C3—C16122.38 (11)H16A—C16—H16B107.7
C2—C3—C16119.96 (12)C18—C17—C19110.81 (10)
C5—C4—C3121.14 (11)C18—C17—C16110.33 (10)
C5—C4—H4A119.4C19—C17—C16111.19 (11)
C3—C4—H4A119.4C18—C17—H17A108.1
C4—C5—C6120.94 (12)C19—C17—H17A108.1
C4—C5—H5A119.5C16—C17—H17A108.1
C6—C5—H5A119.5C17—C18—H18A109.5
C1—C6—C5117.83 (11)C17—C18—H18B109.5
C1—C6—C7120.37 (11)H18A—C18—H18B109.5
C5—C6—C7121.72 (11)C17—C18—H18C109.5
C8—C7—C6110.83 (9)H18A—C18—H18C109.5
C8—C7—C20109.81 (11)H18B—C18—H18C109.5
C6—C7—C20111.38 (10)C17—C19—H19A109.5
C8—C7—H7A108.2C17—C19—H19B109.5
C6—C7—H7A108.2H19A—C19—H19B109.5
C20—C7—H7A108.2C17—C19—H19C109.5
O1—C8—N1119.05 (10)H19A—C19—H19C109.5
O1—C8—C7122.79 (11)H19B—C19—H19C109.5
N1—C8—C7118.16 (11)C7—C20—H20A109.5
N2—C9—C10115.30 (10)C7—C20—H20B109.5
N2—C9—C21123.58 (12)H20A—C20—H20B109.5
C10—C9—C21121.11 (10)C7—C20—H20C109.5
C15—C10—C11118.33 (11)H20A—C20—H20C109.5
C15—C10—C9120.84 (10)H20B—C20—H20C109.5
C11—C10—C9120.81 (11)C9—C21—H21A109.5
C12—C11—C10120.94 (11)C9—C21—H21B109.5
C12—C11—H11A119.5H21A—C21—H21B109.5
C10—C11—H11A119.5C9—C21—H21C109.5
C11—C12—C13118.92 (10)H21A—C21—H21C109.5
C11—C12—H12A120.5H21B—C21—H21C109.5
C13—C12—H12A120.5
C8—N1—N2—C9178.11 (10)N2—C9—C10—C15163.79 (11)
C6—C1—C2—C31.07 (17)C21—C9—C10—C15−14.89 (17)
C1—C2—C3—C4−1.20 (17)N2—C9—C10—C11−14.87 (16)
C1—C2—C3—C16177.46 (10)C21—C9—C10—C11166.45 (11)
C2—C3—C4—C50.48 (17)C15—C10—C11—C12−1.73 (17)
C16—C3—C4—C5−178.13 (10)C9—C10—C11—C12176.97 (11)
C3—C4—C5—C60.37 (17)C10—C11—C12—C131.28 (18)
C2—C1—C6—C5−0.19 (16)C11—C12—C13—C14−0.03 (18)
C2—C1—C6—C7176.58 (10)C11—C12—C13—N3−179.31 (11)
C4—C5—C6—C1−0.52 (16)O3—N3—C13—C1416.88 (16)
C4—C5—C6—C7−177.24 (10)O2—N3—C13—C14−162.63 (11)
C1—C6—C7—C8120.04 (12)O3—N3—C13—C12−163.82 (11)
C5—C6—C7—C8−63.31 (14)O2—N3—C13—C1216.67 (16)
C1—C6—C7—C20−117.38 (12)C12—C13—C14—C15−0.72 (18)
C5—C6—C7—C2059.26 (14)N3—C13—C14—C15178.56 (10)
N2—N1—C8—O1−175.54 (10)C13—C14—C15—C100.24 (18)
N2—N1—C8—C75.01 (16)C11—C10—C15—C140.95 (17)
C6—C7—C8—O196.99 (14)C9—C10—C15—C14−177.74 (11)
C20—C7—C8—O1−26.50 (16)C4—C3—C16—C17101.68 (13)
C6—C7—C8—N1−83.58 (13)C2—C3—C16—C17−76.91 (14)
C20—C7—C8—N1152.94 (11)C3—C16—C17—C18166.22 (11)
N1—N2—C9—C10−178.57 (9)C3—C16—C17—C19−70.42 (14)
N1—N2—C9—C210.07 (16)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O1i0.892.133.0012 (16)167
C1—H1A···O2ii0.932.583.4118 (15)149
C16—H16B···Cg1iii0.972.883.6113 (16)133
C18—H18B···Cg2iv0.962.993.9348 (16)167
C21—H21C···Cg1v0.962.803.5600 (16)137
Symmetry codes: (i) −x+1, −y+3, −z+2; (ii) −x+1, y+1/2, −z+3/2; (iii) −x+2, −y+2, −z+2; (iv) x+1, −y+1/2, z−1/2; (v) −x+1, −y+2, −z+2.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O1i0.892.133.0012 (16)167
C1—H1A···O2ii0.932.583.4118 (15)149
C16—H16B···Cg1iii0.972.883.6113 (16)133
C18—H18B···Cg2iv0.962.993.9348 (16)167
C21—H21C···Cg1v0.962.803.5600 (16)137
Symmetry codes: (i) −x+1, −y+3, −z+2; (ii) −x+1, y+1/2, −z+3/2; (iii) −x+2, −y+2, −z+2; (iv) x+1, −y+1/2, z−1/2; (v) −x+1, −y+2, −z+2.
Acknowledgements top

KVS and BK are grateful to Kerala State Council for Science Technology and Environment, Thiruvananthapuram for the financial assistance. The authors also thank the Universiti Sains Malaysia for the Research University Golden Goose Grant No. 1001/PFIZIK/811012.

references
References top

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.

Amir, M. & Kumar, S. (2007). Acta Pharm. 57, 31–45.

Bedia, K.-K., Elçin, O., Seda, U., Fatma, K., Nathaly, S., Sevim, R. & Dimoglo, A. (2006). Eur. J. Med. Chem. 41, 1253–1261.

Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.

Fun, H.-K., Patil, P. S., Rao, J. N., Kalluraya, B. & Chantrapromma, S. (2008). Acta Cryst. E64, o1707.

Pasha, M. A. & Nanjundaswamy, H. M. (2004). Synth. Commun. 34, 3827–3831.

Rollas, S., Gülerman, N. & Erdeniz, H. (2002). Farmaco, 57, 171–174.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13.

Sridhar, R. & Perumal, P. T. (2003). Synth. Commun. 33, 1483–1488.

Terzioglu, N. & Gürsoy, A. (2003). Eur. J. Med. Chem. 38, 781–786.