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

Journal logoCRYSTALLOGRAPHIC
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ISSN: 2056-9890
Volume 65| Part 5| May 2009| Page o1029

Ethyl 2-[(4-chloro­phen­yl)hydrazono]-3-oxo­butanoate

aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bCrystal Materials Research Unit, Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat-Yai, Songkhla 90112, Thailand, and cDepartment of Chemistry, National Institute of Technology–Karnataka, Surathkal, Mangalore 575 025, India
*Correspondence e-mail: hkfun@usm.my

(Received 3 April 2009; accepted 6 April 2009; online 10 April 2009)

The mol­ecule of the title oxobutanoate derivative, C12H13ClN2O3, is nearly planar; the inter­planar angle between the benzene ring and the mean plane through the hydrazono-3-oxobutanoate unit is 2.69 (3)°. An intra­molecular N—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal packing, C—H⋯O(3-oxo) inter­actions link mol­ecules into dimers. The dimers thus formed are linked through C—H⋯O(carboxyl­ate C=O) inter­actions, leading to the formation of ribbons along the [01[\overline 1]] direction, which are stabilized via Cl⋯Cl [3.2916 (3) Å] contacts. The ribbons are stacked via C⋯O contacts [3.2367 (12)–3.3948 (12) Å].

Related literature

For hydrogen-bond motifs, see Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]). For background to the bioactivity and applications of oxobutanoate derivatives, see: Alpaslan et al. (2005[Alpaslan, G., Özdamar, O., Odabaşogˇlu, M., Ersanlı, C. C., Erdönmez, A. & Ocak Ískeleli, N. (2005). Acta Cryst. E61, o3442-o3444.]); Billington et al. (1979[Billington, D. C., Golding, B. T. & Primrose, S. B. (1979). Biochem. J. 182, 827-836.]); Stancho et al. (2008[Stancho, S., Georgi, M., Frank, J. & Ilia, M. (2008). Eur. J. Med. Chem. 43, 694-706.]). For the synthesis, see Amir & Agarwal (1997[Amir, M. & Agarwal, R. (1997). J. Indian Chem. Soc. 74, 154-155.]). For the stability of the temperature controller used in the data collection, see Cosier & Glazer (1986[Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105-107.]).

[Scheme 1]

Experimental

Crystal data
  • C12H13ClN2O3

  • Mr = 268.69

  • Monoclinic, P 21 /c

  • a = 4.0259 (1) Å

  • b = 17.0892 (4) Å

  • c = 18.4934 (5) Å

  • β = 96.802 (1)°

  • V = 1263.38 (6) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.30 mm−1

  • T = 100 K

  • 0.77 × 0.13 × 0.06 mm

Data collection
  • Bruker APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.799, Tmax = 0.982

  • 38796 measured reflections

  • 4723 independent reflections

  • 3972 reflections with I > 2σ(I)

  • Rint = 0.039

Refinement
  • R[F2 > 2σ(F2)] = 0.037

  • wR(F2) = 0.108

  • S = 1.06

  • 4723 reflections

  • 165 parameters

  • H-atom parameters constrained

  • Δρmax = 0.53 e Å−3

  • Δρmin = −0.24 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯O1 0.91 1.87 2.5721 (12) 132
C2—H2A⋯O2i 0.93 2.45 3.3536 (13) 164
C5—H5A⋯O1ii 0.93 2.53 3.4293 (12) 163
Symmetry codes: (i) [-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (ii) -x+3, -y+1, -z+2.

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2005[Bruker (2005). 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

Derivatives of oxobutanoates are biologically important. 4-Methylthio-2-oxobutanoate was identified in the culture fluids of a range of bacteria, e.g. the yeast Saccharomyces cerevisiae and the fungus Penicillium digitatum (Billington et al., 1979). Some oxobutanoates exhibit cytotoxic properties (Stancho et al., 2008). The crystal structure of ethyl 4-chloro-2-[2-(2-methoxyphenyl)hydrazono]-3-oxobutanoate has been reported (Alpaslan et al., 2005).

The molecule of the title oxobutanoate derivative, (I), is nearly planar which can be readily indicated by the interplanar angle between the benzene ring and the mean plane through the hydrazono-3-oxobutanoate unit (N1–N2/O1–O3/C7–C10) is 2.69 (3)°, and the C10–C7–C8–C9 torsion angle of 2.81 (15)°. The ethyl group is slightly deviated from the mean plane of the molecule with the torsion angle C10–O3–C11–C12 being 170.6 (9)°. Within the molecule, an intramolecular N1—H1···O1 hydrogen bond generates a S(6) ring motif (Bernstein et al., 1995) (Table 1).

In the crystal packing, the C5—H5A···O1 interactions link two molecules into a dimer (Table 1 and Fig. 2). The dimers are linked together through C2—H2A···O2 interactions to form molecular ribbons along the [011] direction; these ribbons are further stabilized by Cl···Cl [3.2916 (3)Å] contacts. These ribbons are stacked, being connected by C···O [3.2367 (12), 3.3716 (14) and 3.3948 (12)Å] contacts.

Related literature top

For hydrogen-bond motifs, see Bernstein et al. (1995). For background to the bioactivity and applications of oxobutanoate derivatives, see, for example: Alpaslan et al. (2005); Billington et al. (1979); Stancho et al. (2008). For the synthesis, see Amir & Agarwal (1997). For the stability of the temperature controller used in the data collection, see Cosier & Glazer (1986).

Experimental top

Compound (I) was prepared as reported in literature (Amir & Agarwal, 1997). 4-Chloroaniline (1.27 g, 10 mmol) was dissolved in dilute hydrochloric acid (11.0 ml) and cooled to 273 K in an ice bath. To this cold solution, sodium nitrite (1.6 g in 5.0 ml water) was added. The temperature of the reaction mixture was not allowed to raise above 323 K. The resulting diazonium salt solution was then filtered into a cooled solution of ethylacetoacetate (1.7 ml) and sodium acetate (3.5 g) in ethanol (50 ml). The resulting yellow solid was filtered, washed with ice-cold water, dried and recrystallized from methanol. The yield was 1.95 g (81%); M.p. 365 K.

Refinement top

All H atoms were placed in calculated positions with d(N—H) = 0.91 Å, d(C—H) = 0.93 Å for aromatic, 0.97 Å for CH2 and 0.96 Å for CH3 atoms. The Uiso values were constrained to be 1.5Ueq of the carrier atom for methyl-H atoms and 1.2Ueq for the remaining H atoms. A rotating group model was used for the methyl substituents.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (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, 2009).

Figures top
[Figure 1] Fig. 1. The structure of (I), showing 50% probability displacement ellipsoids and the atom-numbering scheme. The N—H···O hydrogen bond was drawn as a dashed line.
[Figure 2] Fig. 2. The packing diagram of (I), viewed along in projection the a axis, showing the arrangement of the dimers into molecular ribbons. C—H···O contacts are shown as dashed lines.
Ethyl 2-[(4-chlorophenyl)hydrazono]-3-oxobutanoate top
Crystal data top
C12H13ClN2O3F(000) = 560
Mr = 268.69Dx = 1.413 Mg m3
Monoclinic, P21/cMelting point: 365 K
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 4.0259 (1) ÅCell parameters from 4723 reflections
b = 17.0892 (4) Åθ = 1.6–32.9°
c = 18.4934 (5) ŵ = 0.30 mm1
β = 96.802 (1)°T = 100 K
V = 1263.38 (6) Å3Needle, brown
Z = 40.77 × 0.13 × 0.06 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer
4723 independent reflections
Radiation source: sealed tube3972 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.039
ϕ and ω scansθmax = 32.9°, θmin = 1.6°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
h = 66
Tmin = 0.799, Tmax = 0.982k = 2625
38796 measured reflectionsl = 2828
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)] = 0.037Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.108H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0602P)2 + 0.255P]
where P = (Fo2 + 2Fc2)/3
4723 reflections(Δ/σ)max = 0.002
165 parametersΔρmax = 0.53 e Å3
0 restraintsΔρmin = 0.24 e Å3
Crystal data top
C12H13ClN2O3V = 1263.38 (6) Å3
Mr = 268.69Z = 4
Monoclinic, P21/cMo Kα radiation
a = 4.0259 (1) ŵ = 0.30 mm1
b = 17.0892 (4) ÅT = 100 K
c = 18.4934 (5) Å0.77 × 0.13 × 0.06 mm
β = 96.802 (1)°
Data collection top
Bruker APEXII CCD area-detector
diffractometer
4723 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
3972 reflections with I > 2σ(I)
Tmin = 0.799, Tmax = 0.982Rint = 0.039
38796 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0370 restraints
wR(F2) = 0.108H-atom parameters constrained
S = 1.06Δρmax = 0.53 e Å3
4723 reflectionsΔρmin = 0.24 e Å3
165 parameters
Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

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
Cl11.33403 (7)0.917736 (14)0.966487 (14)0.02331 (8)
O11.1283 (2)0.43897 (5)0.92388 (4)0.02458 (17)
O20.4082 (2)0.41534 (4)0.74203 (5)0.02490 (17)
O30.40449 (18)0.54627 (4)0.73206 (4)0.01834 (15)
N11.0478 (2)0.58595 (5)0.89744 (5)0.01680 (16)
H11.14610.54840.92770.020*
N20.8324 (2)0.56553 (5)0.84259 (4)0.01607 (15)
C10.9700 (2)0.72408 (6)0.86488 (5)0.01779 (18)
H1A0.82690.71090.82350.021*
C21.0384 (3)0.80222 (6)0.88190 (5)0.01815 (18)
H2A0.94130.84180.85210.022*
C31.2535 (2)0.82023 (5)0.94400 (5)0.01668 (17)
C41.4070 (2)0.76234 (6)0.98899 (5)0.01816 (18)
H4A1.55300.77561.02990.022*
C51.3393 (2)0.68425 (6)0.97197 (5)0.01727 (17)
H5A1.44080.64471.00130.021*
C61.1185 (2)0.66568 (5)0.91065 (5)0.01550 (17)
C70.7628 (2)0.49093 (5)0.82808 (5)0.01602 (17)
C80.9246 (2)0.42509 (6)0.86964 (5)0.01779 (18)
C90.8553 (3)0.34161 (6)0.84741 (6)0.02176 (19)
H9A0.98750.30740.88040.033*
H9B0.91160.33370.79890.033*
H9C0.62230.33040.84860.033*
C100.5100 (2)0.47889 (6)0.76369 (5)0.01646 (17)
C110.1696 (2)0.53891 (6)0.66655 (5)0.01926 (18)
H11A0.01310.50440.67520.023*
H11B0.28040.51740.62720.023*
C120.0397 (3)0.61975 (7)0.64728 (6)0.0245 (2)
H12A0.11230.61750.60320.037*
H12B0.22350.65360.64030.037*
H12C0.07490.63970.68610.037*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.03064 (14)0.01473 (12)0.02328 (13)0.00497 (9)0.00211 (9)0.00104 (8)
O10.0277 (4)0.0185 (3)0.0251 (4)0.0003 (3)0.0070 (3)0.0031 (3)
O20.0306 (4)0.0165 (3)0.0254 (4)0.0037 (3)0.0057 (3)0.0015 (3)
O30.0185 (3)0.0163 (3)0.0190 (3)0.0001 (2)0.0030 (2)0.0012 (2)
N10.0185 (4)0.0146 (3)0.0163 (4)0.0003 (3)0.0018 (3)0.0001 (3)
N20.0163 (3)0.0162 (3)0.0156 (3)0.0012 (3)0.0012 (3)0.0015 (3)
C10.0200 (4)0.0162 (4)0.0162 (4)0.0009 (3)0.0022 (3)0.0005 (3)
C20.0203 (4)0.0157 (4)0.0176 (4)0.0005 (3)0.0011 (3)0.0010 (3)
C30.0191 (4)0.0137 (4)0.0170 (4)0.0018 (3)0.0014 (3)0.0006 (3)
C40.0187 (4)0.0179 (4)0.0169 (4)0.0016 (3)0.0023 (3)0.0007 (3)
C50.0178 (4)0.0163 (4)0.0169 (4)0.0000 (3)0.0014 (3)0.0011 (3)
C60.0163 (4)0.0135 (4)0.0165 (4)0.0005 (3)0.0012 (3)0.0003 (3)
C70.0168 (4)0.0147 (4)0.0162 (4)0.0008 (3)0.0002 (3)0.0008 (3)
C80.0189 (4)0.0155 (4)0.0189 (4)0.0003 (3)0.0019 (3)0.0015 (3)
C90.0250 (5)0.0149 (4)0.0248 (5)0.0003 (4)0.0001 (4)0.0017 (3)
C100.0170 (4)0.0162 (4)0.0160 (4)0.0005 (3)0.0015 (3)0.0001 (3)
C110.0186 (4)0.0216 (4)0.0169 (4)0.0008 (3)0.0012 (3)0.0006 (3)
C120.0238 (5)0.0235 (5)0.0253 (5)0.0032 (4)0.0016 (4)0.0039 (4)
Geometric parameters (Å, º) top
Cl1—C31.7386 (9)C4—H4A0.9300
O1—C81.2412 (12)C5—C61.3924 (13)
O2—C101.2121 (12)C5—H5A0.9300
O3—C101.3378 (12)C7—C81.4703 (13)
O3—C111.4514 (11)C7—C101.4864 (13)
N1—N21.3018 (11)C8—C91.5017 (14)
N1—C61.4072 (12)C9—H9A0.9600
N1—H10.9104C9—H9B0.9600
N2—C71.3258 (12)C9—H9C0.9600
C1—C21.3918 (14)C11—C121.5049 (15)
C1—C61.3964 (13)C11—H11A0.9700
C1—H1A0.9300C11—H11B0.9700
C2—C31.3885 (13)C12—H12A0.9600
C2—H2A0.9300C12—H12B0.9600
C3—C41.3895 (13)C12—H12C0.9600
C4—C51.3906 (14)
C10—O3—C11115.60 (8)C8—C7—C10122.13 (8)
N2—N1—C6119.81 (8)O1—C8—C7119.05 (9)
N2—N1—H1119.4O1—C8—C9119.11 (9)
C6—N1—H1120.7C7—C8—C9121.82 (9)
N1—N2—C7121.37 (8)C8—C9—H9A109.5
C2—C1—C6119.32 (9)C8—C9—H9B109.5
C2—C1—H1A120.3H9A—C9—H9B109.5
C6—C1—H1A120.3C8—C9—H9C109.5
C3—C2—C1119.14 (9)H9A—C9—H9C109.5
C3—C2—H2A120.4H9B—C9—H9C109.5
C1—C2—H2A120.4O2—C10—O3123.32 (9)
C2—C3—C4121.80 (9)O2—C10—C7124.16 (9)
C2—C3—Cl1119.38 (7)O3—C10—C7112.52 (8)
C4—C3—Cl1118.82 (7)O3—C11—C12106.97 (8)
C3—C4—C5119.11 (9)O3—C11—H11A110.3
C3—C4—H4A120.4C12—C11—H11A110.3
C5—C4—H4A120.4O3—C11—H11B110.3
C4—C5—C6119.48 (9)C12—C11—H11B110.3
C4—C5—H5A120.3H11A—C11—H11B108.6
C6—C5—H5A120.3C11—C12—H12A109.5
C5—C6—C1121.12 (9)C11—C12—H12B109.5
C5—C6—N1117.30 (8)H12A—C12—H12B109.5
C1—C6—N1121.57 (8)C11—C12—H12C109.5
N2—C7—C8124.07 (8)H12A—C12—H12C109.5
N2—C7—C10113.78 (8)H12B—C12—H12C109.5
C6—N1—N2—C7179.20 (9)N1—N2—C7—C82.05 (15)
C6—C1—C2—C30.13 (15)N1—N2—C7—C10179.71 (9)
C1—C2—C3—C41.12 (16)N2—C7—C8—O13.50 (16)
C1—C2—C3—Cl1178.83 (8)C10—C7—C8—O1178.40 (10)
C2—C3—C4—C51.00 (15)N2—C7—C8—C9175.28 (10)
Cl1—C3—C4—C5178.94 (8)C10—C7—C8—C92.81 (15)
C3—C4—C5—C60.36 (15)C11—O3—C10—O23.29 (14)
C4—C5—C6—C11.61 (15)C11—O3—C10—C7177.01 (8)
C4—C5—C6—N1177.46 (9)N2—C7—C10—O2178.82 (10)
C2—C1—C6—C51.49 (15)C8—C7—C10—O22.90 (16)
C2—C1—C6—N1177.54 (9)N2—C7—C10—O30.88 (12)
N2—N1—C6—C5177.14 (9)C8—C7—C10—O3177.40 (9)
N2—N1—C6—C11.93 (15)C10—O3—C11—C12170.62 (9)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O10.911.872.5721 (12)132
C2—H2A···O2i0.932.453.3536 (13)164
C5—H5A···O1ii0.932.533.4293 (12)163
Symmetry codes: (i) x+1, y+1/2, z+3/2; (ii) x+3, y+1, z+2.

Experimental details

Crystal data
Chemical formulaC12H13ClN2O3
Mr268.69
Crystal system, space groupMonoclinic, P21/c
Temperature (K)100
a, b, c (Å)4.0259 (1), 17.0892 (4), 18.4934 (5)
β (°) 96.802 (1)
V3)1263.38 (6)
Z4
Radiation typeMo Kα
µ (mm1)0.30
Crystal size (mm)0.77 × 0.13 × 0.06
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.799, 0.982
No. of measured, independent and
observed [I > 2σ(I)] reflections
38796, 4723, 3972
Rint0.039
(sin θ/λ)max1)0.764
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.108, 1.06
No. of reflections4723
No. of parameters165
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.53, 0.24

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O10.911.872.5721 (12)132
C2—H2A···O2i0.932.453.3536 (13)164
C5—H5A···O1ii0.932.533.4293 (12)163
Symmetry codes: (i) x+1, y+1/2, z+3/2; (ii) x+3, y+1, z+2.
 

Footnotes

Thomson Reuters Researcher ID: A-3561-2009.

§Additional correspondence author, e-mail: suchada.c@psu.ac.th. Thomson Reuters Researcher ID: A-5085-2009.

Acknowledgements

AMI is grateful to the Head of the Department of Chemistry and the Director, NITK, Surathkal, India, for providing research facilities. The authors thank the Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

References

First citationAlpaslan, G., Özdamar, O., Odabaşogˇlu, M., Ersanlı, C. C., Erdönmez, A. & Ocak Ískeleli, N. (2005). Acta Cryst. E61, o3442–o3444.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationAmir, M. & Agarwal, R. (1997). J. Indian Chem. Soc. 74, 154–155.  CAS Google Scholar
First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.  CrossRef CAS Web of Science Google Scholar
First citationBillington, D. C., Golding, B. T. & Primrose, S. B. (1979). Biochem. J. 182, 827–836.  CAS PubMed Web of Science Google Scholar
First citationBruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationCosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107.  CrossRef CAS Web of Science 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
First citationStancho, S., Georgi, M., Frank, J. & Ilia, M. (2008). Eur. J. Med. Chem. 43, 694–706.  Web of Science PubMed Google Scholar

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Volume 65| Part 5| May 2009| Page o1029
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