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ISSN: 2056-9890

4-[2-(2-Meth­­oxy­phen­yl)hydrazinyl­­idene]-3-methyl-5-oxo-4,5-di­hydro-1H-pyrazole-1-carbo­thio­amide

aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and bDepartment of Studies in Chemistry, Mangalore University, Mangalagangothri 574 199, Karnataka, India
*Correspondence e-mail: hkfun@usm.my

(Received 12 September 2011; accepted 16 September 2011; online 30 September 2011)

In the title mol­ecule, C12H13N5O2S, a bifurcated intra­molecular N—H⋯O(O) hydrogen bond forms two S(6) ring motifs. The benzene ring forms a dihedral angle of 14.36 (11)° with the pyrazole ring. In the crystal, pairs of N—H⋯S hydrogen bonds form centrosymmetric dimers, generating R22(8) ring motifs, which stack along the b axis.

Related literature

For applications of pyrazole derivatives, see: Rai et al. (2008[Rai, N. S., Kalluraya, B., Lingappa, B., Shenoy, S. & Puranic, V. G. (2008). Eur. J. Med. Chem. 43, 1715-1720.]); Isloor et al. (2009[Isloor, A. M., Kalluraya, B. & Shetty, P. (2009). Eur. J. Med. Chem. 44, 3784-3787.]); Girisha et al. (2010[Girisha, K. S., Kalluraya, B., Narayana, V. & Padmashree (2010). Eur. J. Med. Chem. 45, 4640-4644.]). For standard bond-length data, see: Allen et al. (1987[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.]). 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.]).

[Scheme 1]

Experimental

Crystal data
  • C12H13N5O2S

  • Mr = 291.33

  • Monoclinic, P 2/c

  • a = 14.3207 (13) Å

  • b = 5.2003 (5) Å

  • c = 19.5919 (18) Å

  • β = 108.369 (2)°

  • V = 1384.7 (2) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.24 mm−1

  • T = 296 K

  • 0.61 × 0.28 × 0.08 mm

Data collection
  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.866, Tmax = 0.980

  • 26169 measured reflections

  • 4567 independent reflections

  • 3273 reflections with I > 2σ(I)

  • Rint = 0.061

Refinement
  • R[F2 > 2σ(F2)] = 0.060

  • wR(F2) = 0.187

  • S = 1.05

  • 4567 reflections

  • 195 parameters

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

  • Δρmax = 0.60 e Å−3

  • Δρmin = −0.34 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1N1⋯O2 0.85 (3) 2.13 (3) 2.775 (2) 133 (2)
N5—H2N5⋯O2 0.89 (3) 1.98 (3) 2.715 (3) 138 (3)
N5—H1N5⋯S1i 0.86 (3) 2.52 (3) 3.366 (2) 168 (2)
Symmetry code: (i) -x, -y, -z.

Data collection: APEX2 (Bruker, 2009[Bruker (2009). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). SADABS, APEX2 and SAINT. 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

Pyrazoles are a novel class of heterocyclic compounds possessing a wide variety of application in the agrochemical and pharmaceutical industries. Derivatives of pyrazoles are found to show good antibacterial (Rai et al., 2008), anti-inflammatory, analgesic (Isloor et al., 2009), and anticancer activities. Pyrazolines are well known and important nitrogen-containing five membered heterocyclic compounds. Several pyrazoline derivatives have been found to possess considerable biological activities which stimulated research activities in this field (Girisha et al., 2010). In view of these observations and in continuation of our search for biologically active pyrazole derivatives, we herein report the crystal structure of the title compound.

In the molecular structure (Fig. 1), an intramolecular N1—H1N1···O2 and N5—H2N5···O2 hydrogen bond (Table 1) stabilize the molecular structure and forms two S(6) ring motifs (Bernstein et al., 1995). The mean planes of the benzene ring (C1–C6) and the 4,5-dihydro-1H-pyrazole ring (N3/N4/C7–C9) form a dihedral angle of 14.36 (11)°. Bond lengths (Allen et al., 1987) and angles are within normal range.

The crystal packing is shown in Fig. 2. Molecules are linked by pairs of intermolecular N5—H1N5···S1i hydrogen bonds (Table 1) to form dimers, generating R22(8) ring motifs (Bernstein et al., 1995) and these sets of ring motifs are stacked along the b axis.

Related literature top

For applications of pyrazole derivatives, see: Rai et al. (2008); Isloor et al. (2009); Girisha et al. (2010). For standard bond-length data, see: Allen et al. (1987). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

To a solution of ethyl 2-[(2-methoxyphenyl)hydrazono]-3-oxobutanoate (0.01 mol) in glacial acetic acid (20 ml), a solution of thiosemicarbazide (0.02 mol) in glacial acetic acid (15 ml) was added and the mixture was refluxed for 4 h. It is cooled and allowed to stand overnight. The solid product that separated out was filtered and dried. It was then recrystallized from ethanol. Crystals suitable for X-ray analysis were obtained from 1:2 mixtures of DMF and ethanol by slow evaporation.

Refinement top

N-bound H atoms was located from the difference map and refined freely, [N–H = 0.85 (3)–0.89 (3) Å]. The remaining H atoms were positioned geometrically [C–H = 0.93 or 0.96 Å] and refined using a riding model with Uiso(H) = 1.2 or 1.5 Ueq(C). A rotating group model was applied to the methyl groups.

Structure description top

Pyrazoles are a novel class of heterocyclic compounds possessing a wide variety of application in the agrochemical and pharmaceutical industries. Derivatives of pyrazoles are found to show good antibacterial (Rai et al., 2008), anti-inflammatory, analgesic (Isloor et al., 2009), and anticancer activities. Pyrazolines are well known and important nitrogen-containing five membered heterocyclic compounds. Several pyrazoline derivatives have been found to possess considerable biological activities which stimulated research activities in this field (Girisha et al., 2010). In view of these observations and in continuation of our search for biologically active pyrazole derivatives, we herein report the crystal structure of the title compound.

In the molecular structure (Fig. 1), an intramolecular N1—H1N1···O2 and N5—H2N5···O2 hydrogen bond (Table 1) stabilize the molecular structure and forms two S(6) ring motifs (Bernstein et al., 1995). The mean planes of the benzene ring (C1–C6) and the 4,5-dihydro-1H-pyrazole ring (N3/N4/C7–C9) form a dihedral angle of 14.36 (11)°. Bond lengths (Allen et al., 1987) and angles are within normal range.

The crystal packing is shown in Fig. 2. Molecules are linked by pairs of intermolecular N5—H1N5···S1i hydrogen bonds (Table 1) to form dimers, generating R22(8) ring motifs (Bernstein et al., 1995) and these sets of ring motifs are stacked along the b axis.

For applications of pyrazole derivatives, see: Rai et al. (2008); Isloor et al. (2009); Girisha et al. (2010). For standard bond-length data, see: Allen et al. (1987). For hydrogen-bond motifs, see: Bernstein et al. (1995).

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 the title compound, showing 30% probability displacement ellipsoids. The dashed lines indicate intramolecular hydrogen bonds.
[Figure 2] Fig. 2. The crystal packing of the title compound. The dashed lines represent the hydrogen bonds.
4-[2-(2-Methoxyphenyl)hydrazinylidene]-3-methyl-5-oxo-4,5-dihydro-1H- pyrazole-1-carbothioamide top
Crystal data top
C12H13N5O2SF(000) = 608
Mr = 291.33Dx = 1.397 Mg m3
Monoclinic, P2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ycCell parameters from 5668 reflections
a = 14.3207 (13) Åθ = 2.2–29.2°
b = 5.2003 (5) ŵ = 0.24 mm1
c = 19.5919 (18) ÅT = 296 K
β = 108.369 (2)°Plate, red
V = 1384.7 (2) Å30.61 × 0.28 × 0.08 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
4567 independent reflections
Radiation source: fine-focus sealed tube3273 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.061
φ and ω scansθmax = 31.4°, θmin = 1.5°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
h = 2020
Tmin = 0.866, Tmax = 0.980k = 77
26169 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)] = 0.060Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.187H atoms treated by a mixture of independent and constrained refinement
S = 1.05 w = 1/[σ2(Fo2) + (0.1052P)2 + 0.245P]
where P = (Fo2 + 2Fc2)/3
4567 reflections(Δ/σ)max < 0.001
195 parametersΔρmax = 0.60 e Å3
0 restraintsΔρmin = 0.34 e Å3
Crystal data top
C12H13N5O2SV = 1384.7 (2) Å3
Mr = 291.33Z = 4
Monoclinic, P2/cMo Kα radiation
a = 14.3207 (13) ŵ = 0.24 mm1
b = 5.2003 (5) ÅT = 296 K
c = 19.5919 (18) Å0.61 × 0.28 × 0.08 mm
β = 108.369 (2)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
4567 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
3273 reflections with I > 2σ(I)
Tmin = 0.866, Tmax = 0.980Rint = 0.061
26169 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0600 restraints
wR(F2) = 0.187H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.60 e Å3
4567 reflectionsΔρmin = 0.34 e Å3
195 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
S10.11741 (4)0.15498 (9)0.09216 (3)0.05009 (17)
O10.17608 (12)1.2296 (3)0.21073 (8)0.0635 (4)
O20.15180 (10)0.6859 (3)0.08927 (7)0.0512 (3)
N10.28202 (12)1.0877 (3)0.08210 (8)0.0464 (4)
N20.32172 (11)1.0371 (3)0.01384 (8)0.0435 (3)
N30.26013 (11)0.5730 (3)0.09587 (7)0.0431 (3)
N40.19132 (10)0.5181 (3)0.02795 (7)0.0402 (3)
N50.06446 (14)0.2838 (4)0.04505 (9)0.0567 (5)
C10.40913 (17)1.3986 (5)0.08198 (11)0.0604 (6)
H1A0.44741.34600.03640.072*
C20.4416 (2)1.5936 (5)0.11722 (13)0.0735 (7)
H2A0.50161.67370.09510.088*
C30.3850 (2)1.6686 (5)0.18496 (12)0.0669 (6)
H3A0.40731.79940.20830.080*
C40.29584 (18)1.5529 (4)0.21881 (11)0.0565 (5)
H4A0.25841.60490.26470.068*
C50.26225 (15)1.3592 (4)0.18418 (9)0.0469 (4)
C60.31955 (14)1.2835 (4)0.11518 (9)0.0457 (4)
C70.28270 (13)0.8477 (3)0.01271 (9)0.0405 (4)
C80.31221 (13)0.7655 (4)0.08639 (9)0.0424 (4)
C90.20102 (13)0.6833 (3)0.02533 (9)0.0399 (3)
C100.38820 (17)0.8850 (4)0.14794 (11)0.0603 (6)
H10A0.39370.78930.19090.090*
H10B0.36971.05910.15380.090*
H10C0.45030.88400.13890.090*
C110.12283 (13)0.3225 (3)0.02151 (9)0.0398 (3)
C120.1117 (2)1.3083 (6)0.27861 (13)0.0755 (7)
H12A0.05721.19120.29390.113*
H12B0.14651.30880.31320.113*
H12C0.08771.47820.27470.113*
H1N10.231 (2)1.010 (5)0.1081 (15)0.081 (9)*
H1N50.0188 (18)0.171 (5)0.0500 (14)0.060 (7)*
H2N50.071 (2)0.387 (6)0.0797 (15)0.074 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.0585 (3)0.0470 (3)0.0424 (3)0.01645 (19)0.01250 (19)0.00532 (18)
O10.0680 (9)0.0748 (10)0.0413 (7)0.0202 (8)0.0081 (6)0.0067 (7)
O20.0618 (8)0.0567 (8)0.0309 (6)0.0155 (6)0.0087 (5)0.0023 (5)
N10.0569 (9)0.0484 (8)0.0337 (7)0.0151 (7)0.0141 (6)0.0030 (6)
N20.0532 (8)0.0441 (8)0.0353 (7)0.0102 (6)0.0167 (6)0.0015 (6)
N30.0509 (8)0.0433 (8)0.0315 (6)0.0117 (6)0.0077 (5)0.0021 (5)
N40.0490 (7)0.0384 (7)0.0309 (6)0.0117 (6)0.0095 (5)0.0003 (5)
N50.0659 (10)0.0568 (10)0.0396 (8)0.0278 (9)0.0055 (7)0.0027 (7)
C10.0693 (12)0.0694 (13)0.0394 (9)0.0247 (11)0.0130 (8)0.0099 (9)
C20.0822 (15)0.0808 (16)0.0541 (13)0.0374 (13)0.0167 (11)0.0121 (11)
C30.0923 (16)0.0626 (13)0.0486 (11)0.0257 (12)0.0263 (11)0.0096 (9)
C40.0801 (13)0.0552 (12)0.0364 (9)0.0072 (10)0.0214 (9)0.0065 (8)
C50.0611 (10)0.0479 (10)0.0334 (8)0.0078 (8)0.0173 (7)0.0015 (7)
C60.0605 (10)0.0449 (9)0.0351 (8)0.0100 (8)0.0202 (7)0.0023 (7)
C70.0485 (8)0.0396 (8)0.0345 (8)0.0097 (7)0.0148 (6)0.0002 (6)
C80.0498 (9)0.0432 (9)0.0330 (7)0.0115 (7)0.0112 (6)0.0000 (6)
C90.0490 (8)0.0382 (8)0.0330 (7)0.0060 (6)0.0135 (6)0.0011 (6)
C100.0682 (12)0.0665 (13)0.0387 (9)0.0277 (10)0.0060 (8)0.0003 (9)
C110.0457 (8)0.0332 (8)0.0394 (8)0.0054 (6)0.0116 (6)0.0010 (6)
C120.0713 (14)0.106 (2)0.0429 (11)0.0109 (14)0.0086 (10)0.0023 (12)
Geometric parameters (Å, º) top
S1—C111.6578 (17)C1—H1A0.9300
O1—C51.357 (2)C2—C31.375 (3)
O1—C121.419 (3)C2—H2A0.9300
O2—C91.229 (2)C3—C41.378 (3)
N1—N21.305 (2)C3—H3A0.9300
N1—C61.402 (2)C4—C51.383 (3)
N1—H1N10.85 (3)C4—H4A0.9300
N2—C71.317 (2)C5—C61.399 (3)
N3—C81.296 (2)C7—C81.435 (2)
N3—N41.4131 (18)C7—C91.451 (2)
N4—C111.391 (2)C8—C101.482 (2)
N4—C91.392 (2)C10—H10A0.9600
N5—C111.324 (2)C10—H10B0.9600
N5—H1N50.86 (3)C10—H10C0.9600
N5—H2N50.89 (3)C12—H12A0.9600
C1—C61.379 (3)C12—H12B0.9600
C1—C21.387 (3)C12—H12C0.9600
C5—O1—C12117.38 (18)C1—C6—C5120.59 (17)
N2—N1—C6120.92 (16)C1—C6—N1122.18 (17)
N2—N1—H1N1122.0 (19)C5—C6—N1117.23 (16)
C6—N1—H1N1117.0 (19)N2—C7—C8126.34 (16)
N1—N2—C7116.97 (15)N2—C7—C9127.67 (16)
C8—N3—N4106.45 (13)C8—C7—C9105.98 (14)
C11—N4—C9128.13 (14)N3—C8—C7111.94 (15)
C11—N4—N3119.72 (13)N3—C8—C10121.01 (16)
C9—N4—N3112.12 (13)C7—C8—C10126.96 (16)
C11—N5—H1N5115.8 (17)O2—C9—N4127.62 (15)
C11—N5—H2N5118.4 (18)O2—C9—C7128.89 (15)
H1N5—N5—H2N5125 (2)N4—C9—C7103.49 (14)
C6—C1—C2119.4 (2)C8—C10—H10A109.5
C6—C1—H1A120.3C8—C10—H10B109.5
C2—C1—H1A120.3H10A—C10—H10B109.5
C3—C2—C1120.0 (2)C8—C10—H10C109.5
C3—C2—H2A120.0H10A—C10—H10C109.5
C1—C2—H2A120.0H10B—C10—H10C109.5
C2—C3—C4121.02 (19)N5—C11—N4114.13 (15)
C2—C3—H3A119.5N5—C11—S1124.15 (14)
C4—C3—H3A119.5N4—C11—S1121.72 (13)
C3—C4—C5119.66 (19)O1—C12—H12A109.5
C3—C4—H4A120.2O1—C12—H12B109.5
C5—C4—H4A120.2H12A—C12—H12B109.5
O1—C5—C4126.05 (18)O1—C12—H12C109.5
O1—C5—C6114.59 (16)H12A—C12—H12C109.5
C4—C5—C6119.36 (18)H12B—C12—H12C109.5
C6—N1—N2—C7179.10 (17)N1—N2—C7—C91.2 (3)
C8—N3—N4—C11178.33 (16)N4—N3—C8—C70.7 (2)
C8—N3—N4—C90.3 (2)N4—N3—C8—C10176.20 (18)
C6—C1—C2—C30.7 (4)N2—C7—C8—N3179.65 (18)
C1—C2—C3—C40.1 (4)C9—C7—C8—N31.3 (2)
C2—C3—C4—C50.3 (4)N2—C7—C8—C103.7 (3)
C12—O1—C5—C43.6 (3)C9—C7—C8—C10175.4 (2)
C12—O1—C5—C6176.1 (2)C11—N4—C9—O21.5 (3)
C3—C4—C5—O1179.7 (2)N3—N4—C9—O2179.33 (18)
C3—C4—C5—C60.0 (3)C11—N4—C9—C7178.88 (16)
C2—C1—C6—C50.9 (4)N3—N4—C9—C71.00 (19)
C2—C1—C6—N1179.2 (2)N2—C7—C9—O20.0 (3)
O1—C5—C6—C1179.7 (2)C8—C7—C9—O2179.03 (19)
C4—C5—C6—C10.6 (3)N2—C7—C9—N4179.64 (18)
O1—C5—C6—N10.2 (3)C8—C7—C9—N41.31 (19)
C4—C5—C6—N1179.53 (19)C9—N4—C11—N54.3 (3)
N2—N1—C6—C112.2 (3)N3—N4—C11—N5177.95 (17)
N2—N1—C6—C5167.88 (17)C9—N4—C11—S1176.08 (14)
N1—N2—C7—C8177.67 (17)N3—N4—C11—S11.7 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N1···O20.85 (3)2.13 (3)2.775 (2)133 (2)
N5—H2N5···O20.89 (3)1.98 (3)2.715 (3)138 (3)
N5—H1N5···S1i0.86 (3)2.52 (3)3.366 (2)168 (2)
Symmetry code: (i) x, y, z.

Experimental details

Crystal data
Chemical formulaC12H13N5O2S
Mr291.33
Crystal system, space groupMonoclinic, P2/c
Temperature (K)296
a, b, c (Å)14.3207 (13), 5.2003 (5), 19.5919 (18)
β (°) 108.369 (2)
V3)1384.7 (2)
Z4
Radiation typeMo Kα
µ (mm1)0.24
Crystal size (mm)0.61 × 0.28 × 0.08
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.866, 0.980
No. of measured, independent and
observed [I > 2σ(I)] reflections
26169, 4567, 3273
Rint0.061
(sin θ/λ)max1)0.733
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.060, 0.187, 1.05
No. of reflections4567
No. of parameters195
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.60, 0.34

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

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N1···O20.85 (3)2.13 (3)2.775 (2)133 (2)
N5—H2N5···O20.89 (3)1.98 (3)2.715 (3)138 (3)
N5—H1N5···S1i0.86 (3)2.52 (3)3.366 (2)168 (2)
Symmetry code: (i) x, y, z.
 

Footnotes

Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

The authors thank Universiti Sains Malaysia (USM) for the Research University Grant (1001/PFIZIK/811160). SA also thanks the Malaysian Government and USM for the Academic Staff Training Scheme (ASTS) award.

References

First citationAllen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.  CSD CrossRef Web of Science 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 citationBruker (2009). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationGirisha, K. S., Kalluraya, B., Narayana, V. & Padmashree (2010). Eur. J. Med. Chem. 45, 4640–4644.  Google Scholar
First citationIsloor, A. M., Kalluraya, B. & Shetty, P. (2009). Eur. J. Med. Chem. 44, 3784–3787.  Web of Science CrossRef PubMed CAS Google Scholar
First citationRai, N. S., Kalluraya, B., Lingappa, B., Shenoy, S. & Puranic, V. G. (2008). Eur. J. Med. Chem. 43, 1715–1720.  Web of Science PubMed 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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