organic compounds
3,5-Bis(4-bromophenyl)-1-phenyl-4,5-dihydro-1H-pyrazole
aDepartment of Studies in Chemistry, Mangalore University, Mangalagangotri 574 199, India, bDepartment of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India, and cDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: edward.tiekink@gmail.com
In the title compound, C21H16Br2N2, the central pyrazole ring adopts an flattened with the stereogenic C atom in the flap position. The deviations from planarity for this ring are relatively minor (r.m.s. deviation = 0.045 Å) and the dihedral angles formed with the N- and Cimine-bound benzene rings are 7.73 (13) and 11.00 (13)°, respectively. By contrast, the benzene ring bound at the chiral C atom is almost orthogonal to the rest of the molecule; the dihedral angle formed between this ring and the pyrazole ring is 79.53 (13)°. In the crystal, the packing is stabilized by C—H⋯N and C—H⋯Br interactions.
Related literature
For the pharmacological activity of pyrazoline derivatives, see: Hes et al. (1978); Amir et al. (2008); Sarojini et al. (2010). For related structures, see: Fun et al. (2010); Yathirajan et al. (2007). For the structure of the parent compound, 1,3,5-triphenyl-2-pyrazoline, see: Foces-Foces et al. (2001). For see: Cremer & Pople (1975).
Experimental
Crystal data
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Data collection: APEX2 (Bruker, 2008); cell SAINT (Bruker, 2008); data reduction: SAINT; 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) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).
Supporting information
https://doi.org/10.1107/S1600536810015795/hb5428sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810015795/hb5428Isup2.hkl
A mixture of (2E)-1,3-bis(4-bromophenyl)prop-2-en-1-one (3.66 g, 0.01 mol) and phenyl hydrazine (1.08 g, 0.01 mol) in glacial acetic acid (50 ml) was refluxed for 6 h. The reaction mixture was cooled and poured into ice-cold water (50 ml). The precipitate was collected by filtration and purified by recrystallization from ethanol. Yellow blocks of (I) were grown from toluene by slow evaporation; the yield was 86%, m.pt. 481 K. Analytical data (%): Found (Calc'd): C 55.21 (55.29); H 3.48 (3.54); N 6.10 (6.14).
Carbon-bound H-atoms were placed in calculated positions (C—H 0.95 to 1.00 Å) and were included in the
in the riding model approximation, with Uiso(H) set to 1.2 to 1.5Ueq(C).Derivatives of pyrazoline possess a range of pharmacological activities, having, for example, anti-tumour, anti-microbial, and anti-tubercular activities (Hes et al., 1978; Amir et al., 2008). Further, some of these compounds also have anti-inflammatory, anti-diabetic, anaesthetic, analgesic and DPPH scavenging properties (Sarojini et al., 2010). In continuation of previous structural studies of pyrazoline derivatives (Fun et al., 2010, Yathirajan et al., 2007), the title compound, (I), was synthesised and its
determined.The structure analysis of (I) shows the C1 centre to have an S configuration, Fig. 1. The conformation of the central pyrazole ring is an envelope on the C1 atom as defined by the ring-puckering parameters of q2 = 0.101 (3) Å and φ2 = 251.7 (14) ° (Cremer & Pople, 1975). That being stated, the maximum deviations from the five atoms of the ring are 0.052 (2) and -0.064 (3) Å for the N2 and C1 atoms, respectively; the r.m.s. deviation = 0.0450 Å. The N2- and C3-bound benzene rings are approximately co-planar with the central ring as seen in the dihedral angles formed between their respective least-squares planes and that through the pyrazole ring of 7.73 (13) and 11.00 (13) °; the dihedral angle between these benzene rings is 4.32 (12) °. By contrast, the C1-bound benzene ring is almost orthogonal to the remaining molecule with a dihedral angle of 79.53 (13) ° formed between it and the pyrazole ring. To a first approximation, the overall conformation in (I) resembles that in the analogous 1,3,5-triphenyl-2-pyrazoline "parent" compound although the deviations from planarity are slightly greater in the literature structure (Foces-Foces et al., 2001). Further, the N1–N2 [1.369 (3) Å] and N1═C3 [1.291 (3) Å] bond distances in (I) are comparable to the equivalent distances in 1,3,5-triphenyl-2-pyrazoline of 1.387 (5) and 1.285 (7) Å, respectively.
The molecules are consolidated into a 3-D network by C–H···N and C—H···Br contacts, Fig. 2 and Table 1.
For the pharmacological activity of pyrazoline derivatives, see: Hes et al. (1978); Amir et al. (2008); Sarojini et al. (2010). For related structures, see: Fun et al. (2010); Yathirajan et al. (2007). For the structure of the parent compound, 1,3,5-triphenyl-2-pyrazoline, see: Foces-Foces et al. (2001). For
see: Cremer & Pople (1975).Data collection: APEX2 (Bruker, 2008); cell
SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); 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) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).C21H16Br2N2 | F(000) = 904 |
Mr = 456.18 | Dx = 1.652 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 4444 reflections |
a = 10.5815 (3) Å | θ = 2.3–26.2° |
b = 11.2119 (3) Å | µ = 4.43 mm−1 |
c = 15.4569 (4) Å | T = 100 K |
V = 1833.79 (9) Å3 | Block, yellow |
Z = 4 | 0.35 × 0.15 × 0.08 mm |
Bruker SMART APEX diffractometer | 4201 independent reflections |
Radiation source: fine-focus sealed tube | 3753 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.044 |
ω scans | θmax = 27.5°, θmin = 2.2° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −13→13 |
Tmin = 0.537, Tmax = 0.746 | k = −14→14 |
17504 measured reflections | l = −20→20 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.027 | H-atom parameters constrained |
wR(F2) = 0.052 | w = 1/[σ2(Fo2) + (0.0105P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.02 | (Δ/σ)max < 0.001 |
4201 reflections | Δρmax = 0.60 e Å−3 |
226 parameters | Δρmin = −0.40 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 1804 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.003 (7) |
C21H16Br2N2 | V = 1833.79 (9) Å3 |
Mr = 456.18 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 10.5815 (3) Å | µ = 4.43 mm−1 |
b = 11.2119 (3) Å | T = 100 K |
c = 15.4569 (4) Å | 0.35 × 0.15 × 0.08 mm |
Bruker SMART APEX diffractometer | 4201 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 3753 reflections with I > 2σ(I) |
Tmin = 0.537, Tmax = 0.746 | Rint = 0.044 |
17504 measured reflections |
R[F2 > 2σ(F2)] = 0.027 | H-atom parameters constrained |
wR(F2) = 0.052 | Δρmax = 0.60 e Å−3 |
S = 1.02 | Δρmin = −0.40 e Å−3 |
4201 reflections | Absolute structure: Flack (1983), 1804 Friedel pairs |
226 parameters | Absolute structure parameter: 0.003 (7) |
0 restraints |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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. |
x | y | z | Uiso*/Ueq | ||
Br1 | 0.45694 (3) | 0.39983 (2) | −0.095975 (18) | 0.03237 (9) | |
Br2 | 1.28094 (3) | −0.06644 (3) | 0.379191 (19) | 0.02784 (8) | |
N1 | 0.68637 (18) | −0.10495 (19) | 0.19763 (12) | 0.0155 (5) | |
N2 | 0.56377 (19) | −0.07418 (19) | 0.18013 (13) | 0.0175 (5) | |
C1 | 0.5321 (3) | 0.0486 (2) | 0.20739 (15) | 0.0184 (5) | |
H1 | 0.4556 | 0.0479 | 0.2453 | 0.022* | |
C2 | 0.6507 (2) | 0.0809 (3) | 0.26139 (16) | 0.0226 (6) | |
H2A | 0.6878 | 0.1576 | 0.2422 | 0.027* | |
H2B | 0.6304 | 0.0859 | 0.3238 | 0.027* | |
C3 | 0.7385 (2) | −0.0217 (2) | 0.24286 (16) | 0.0144 (6) | |
C4 | 0.5117 (2) | 0.1321 (2) | 0.13185 (17) | 0.0165 (6) | |
C5 | 0.4266 (3) | 0.2261 (2) | 0.13916 (17) | 0.0206 (6) | |
H5 | 0.3790 | 0.2351 | 0.1909 | 0.025* | |
C6 | 0.4100 (3) | 0.3064 (2) | 0.07249 (17) | 0.0230 (6) | |
H6 | 0.3521 | 0.3707 | 0.0781 | 0.028* | |
C7 | 0.4791 (3) | 0.2917 (2) | −0.00225 (17) | 0.0208 (6) | |
C8 | 0.5631 (3) | 0.1994 (2) | −0.01219 (16) | 0.0213 (6) | |
H8 | 0.6087 | 0.1901 | −0.0647 | 0.026* | |
C9 | 0.5803 (2) | 0.1200 (2) | 0.05566 (17) | 0.0193 (6) | |
H9 | 0.6394 | 0.0567 | 0.0500 | 0.023* | |
C10 | 0.8685 (2) | −0.0309 (2) | 0.27394 (16) | 0.0141 (6) | |
C11 | 0.9485 (3) | −0.1218 (2) | 0.24481 (16) | 0.0179 (6) | |
H11 | 0.9182 | −0.1784 | 0.2041 | 0.021* | |
C12 | 1.0714 (3) | −0.1300 (2) | 0.27476 (17) | 0.0199 (6) | |
H12 | 1.1256 | −0.1914 | 0.2544 | 0.024* | |
C13 | 1.1146 (2) | −0.0478 (3) | 0.33476 (17) | 0.0190 (6) | |
C14 | 1.0378 (2) | 0.0425 (2) | 0.36482 (16) | 0.0190 (5) | |
H14 | 1.0685 | 0.0981 | 0.4062 | 0.023* | |
C15 | 0.9159 (2) | 0.0512 (2) | 0.33413 (16) | 0.0178 (6) | |
H15 | 0.8631 | 0.1140 | 0.3541 | 0.021* | |
C16 | 0.4888 (2) | −0.1457 (2) | 0.12849 (16) | 0.0168 (5) | |
C17 | 0.3627 (2) | −0.1161 (2) | 0.11246 (16) | 0.0195 (6) | |
H17 | 0.3271 | −0.0468 | 0.1380 | 0.023* | |
C18 | 0.2893 (3) | −0.1876 (3) | 0.05953 (17) | 0.0223 (6) | |
H18 | 0.2036 | −0.1666 | 0.0494 | 0.027* | |
C19 | 0.3379 (3) | −0.2884 (3) | 0.02115 (17) | 0.0222 (6) | |
H19 | 0.2869 | −0.3362 | −0.0157 | 0.027* | |
C20 | 0.4627 (3) | −0.3189 (2) | 0.03732 (17) | 0.0225 (6) | |
H20 | 0.4969 | −0.3886 | 0.0113 | 0.027* | |
C21 | 0.5387 (3) | −0.2497 (2) | 0.09078 (16) | 0.0188 (5) | |
H21 | 0.6236 | −0.2725 | 0.1018 | 0.023* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0559 (2) | 0.01873 (14) | 0.02246 (14) | 0.00349 (14) | −0.01182 (14) | 0.00164 (12) |
Br2 | 0.01697 (13) | 0.03195 (17) | 0.03461 (17) | 0.00011 (12) | −0.00644 (13) | 0.00337 (14) |
N1 | 0.0142 (11) | 0.0171 (11) | 0.0151 (10) | −0.0003 (9) | −0.0004 (8) | 0.0027 (10) |
N2 | 0.0142 (11) | 0.0189 (12) | 0.0193 (10) | 0.0029 (10) | −0.0035 (9) | −0.0018 (9) |
C1 | 0.0191 (14) | 0.0189 (13) | 0.0172 (13) | 0.0012 (12) | 0.0014 (11) | −0.0035 (11) |
C2 | 0.0227 (14) | 0.0244 (16) | 0.0208 (13) | 0.0058 (13) | −0.0072 (12) | −0.0030 (13) |
C3 | 0.0172 (14) | 0.0140 (13) | 0.0121 (12) | −0.0011 (10) | 0.0006 (10) | 0.0028 (10) |
C4 | 0.0134 (13) | 0.0182 (13) | 0.0179 (13) | −0.0005 (10) | −0.0044 (11) | −0.0022 (11) |
C5 | 0.0194 (14) | 0.0231 (14) | 0.0195 (14) | 0.0009 (11) | −0.0028 (11) | −0.0035 (12) |
C6 | 0.0255 (16) | 0.0166 (14) | 0.0269 (16) | 0.0043 (12) | −0.0055 (13) | −0.0047 (12) |
C7 | 0.0284 (17) | 0.0171 (14) | 0.0170 (13) | −0.0012 (12) | −0.0115 (12) | −0.0024 (12) |
C8 | 0.0264 (17) | 0.0217 (15) | 0.0159 (13) | −0.0010 (12) | −0.0008 (12) | −0.0018 (11) |
C9 | 0.0176 (14) | 0.0183 (15) | 0.0219 (13) | 0.0058 (11) | −0.0012 (11) | −0.0030 (12) |
C10 | 0.0150 (14) | 0.0137 (13) | 0.0136 (12) | −0.0018 (10) | 0.0004 (10) | 0.0022 (10) |
C11 | 0.0209 (15) | 0.0173 (14) | 0.0156 (12) | −0.0048 (12) | −0.0016 (12) | −0.0017 (10) |
C12 | 0.0203 (15) | 0.0163 (14) | 0.0232 (14) | 0.0003 (11) | 0.0030 (12) | 0.0011 (11) |
C13 | 0.0124 (13) | 0.0239 (15) | 0.0205 (13) | −0.0005 (11) | −0.0010 (11) | 0.0094 (12) |
C14 | 0.0222 (14) | 0.0176 (13) | 0.0173 (13) | −0.0044 (11) | −0.0033 (12) | 0.0025 (11) |
C15 | 0.0210 (14) | 0.0143 (13) | 0.0180 (13) | 0.0003 (11) | 0.0037 (11) | 0.0002 (11) |
C16 | 0.0189 (13) | 0.0188 (12) | 0.0126 (12) | −0.0049 (10) | 0.0008 (11) | 0.0013 (11) |
C17 | 0.0218 (14) | 0.0186 (13) | 0.0181 (14) | −0.0005 (11) | −0.0008 (12) | 0.0025 (12) |
C18 | 0.0187 (15) | 0.0292 (16) | 0.0190 (14) | −0.0032 (13) | −0.0030 (13) | 0.0058 (12) |
C19 | 0.0255 (16) | 0.0243 (16) | 0.0168 (14) | −0.0098 (13) | −0.0023 (12) | 0.0001 (12) |
C20 | 0.0249 (16) | 0.0230 (14) | 0.0196 (14) | −0.0061 (13) | 0.0040 (13) | −0.0033 (11) |
C21 | 0.0159 (14) | 0.0221 (13) | 0.0183 (13) | −0.0028 (11) | 0.0021 (12) | 0.0021 (12) |
Br1—C7 | 1.903 (3) | C9—H9 | 0.9500 |
Br2—C13 | 1.901 (2) | C10—C11 | 1.399 (4) |
N1—C3 | 1.291 (3) | C10—C15 | 1.402 (4) |
N1—N2 | 1.369 (3) | C11—C12 | 1.383 (4) |
N2—C16 | 1.382 (3) | C11—H11 | 0.9500 |
N2—C1 | 1.478 (3) | C12—C13 | 1.385 (4) |
C1—C4 | 1.512 (4) | C12—H12 | 0.9500 |
C1—C2 | 1.550 (4) | C13—C14 | 1.379 (4) |
C1—H1 | 1.0000 | C14—C15 | 1.377 (4) |
C2—C3 | 1.506 (4) | C14—H14 | 0.9500 |
C2—H2A | 0.9900 | C15—H15 | 0.9500 |
C2—H2B | 0.9900 | C16—C17 | 1.397 (3) |
C3—C10 | 1.461 (4) | C16—C21 | 1.407 (3) |
C4—C9 | 1.390 (4) | C17—C18 | 1.383 (4) |
C4—C5 | 1.391 (4) | C17—H17 | 0.9500 |
C5—C6 | 1.380 (4) | C18—C19 | 1.377 (4) |
C5—H5 | 0.9500 | C18—H18 | 0.9500 |
C6—C7 | 1.377 (4) | C19—C20 | 1.386 (4) |
C6—H6 | 0.9500 | C19—H19 | 0.9500 |
C7—C8 | 1.373 (4) | C20—C21 | 1.390 (4) |
C8—C9 | 1.388 (4) | C20—H20 | 0.9500 |
C8—H8 | 0.9500 | C21—H21 | 0.9500 |
C3—N1—N2 | 109.2 (2) | C11—C10—C15 | 118.4 (2) |
N1—N2—C16 | 120.8 (2) | C11—C10—C3 | 121.0 (2) |
N1—N2—C1 | 113.1 (2) | C15—C10—C3 | 120.6 (2) |
C16—N2—C1 | 125.1 (2) | C12—C11—C10 | 120.6 (2) |
N2—C1—C4 | 112.9 (2) | C12—C11—H11 | 119.7 |
N2—C1—C2 | 100.8 (2) | C10—C11—H11 | 119.7 |
C4—C1—C2 | 112.8 (2) | C11—C12—C13 | 119.3 (2) |
N2—C1—H1 | 110.0 | C11—C12—H12 | 120.3 |
C4—C1—H1 | 110.0 | C13—C12—H12 | 120.3 |
C2—C1—H1 | 110.0 | C14—C13—C12 | 121.3 (2) |
C3—C2—C1 | 102.6 (2) | C14—C13—Br2 | 120.3 (2) |
C3—C2—H2A | 111.2 | C12—C13—Br2 | 118.3 (2) |
C1—C2—H2A | 111.2 | C15—C14—C13 | 119.2 (2) |
C3—C2—H2B | 111.2 | C15—C14—H14 | 120.4 |
C1—C2—H2B | 111.2 | C13—C14—H14 | 120.4 |
H2A—C2—H2B | 109.2 | C14—C15—C10 | 121.1 (2) |
N1—C3—C10 | 122.0 (2) | C14—C15—H15 | 119.4 |
N1—C3—C2 | 113.1 (2) | C10—C15—H15 | 119.4 |
C10—C3—C2 | 124.9 (2) | N2—C16—C17 | 120.9 (2) |
C9—C4—C5 | 118.8 (2) | N2—C16—C21 | 120.3 (2) |
C9—C4—C1 | 121.3 (2) | C17—C16—C21 | 118.8 (2) |
C5—C4—C1 | 119.9 (2) | C18—C17—C16 | 120.3 (3) |
C6—C5—C4 | 121.0 (2) | C18—C17—H17 | 119.9 |
C6—C5—H5 | 119.5 | C16—C17—H17 | 119.9 |
C4—C5—H5 | 119.5 | C19—C18—C17 | 121.4 (3) |
C7—C6—C5 | 118.8 (2) | C19—C18—H18 | 119.3 |
C7—C6—H6 | 120.6 | C17—C18—H18 | 119.3 |
C5—C6—H6 | 120.6 | C18—C19—C20 | 118.7 (3) |
C8—C7—C6 | 121.8 (2) | C18—C19—H19 | 120.6 |
C8—C7—Br1 | 118.3 (2) | C20—C19—H19 | 120.6 |
C6—C7—Br1 | 119.8 (2) | C19—C20—C21 | 121.4 (3) |
C7—C8—C9 | 118.9 (2) | C19—C20—H20 | 119.3 |
C7—C8—H8 | 120.5 | C21—C20—H20 | 119.3 |
C9—C8—H8 | 120.5 | C20—C21—C16 | 119.5 (3) |
C8—C9—C4 | 120.6 (2) | C20—C21—H21 | 120.3 |
C8—C9—H9 | 119.7 | C16—C21—H21 | 120.3 |
C4—C9—H9 | 119.7 | ||
C3—N1—N2—C16 | 176.5 (2) | N1—C3—C10—C11 | 10.1 (4) |
C3—N1—N2—C1 | 7.3 (3) | C2—C3—C10—C11 | −171.9 (2) |
N1—N2—C1—C4 | 110.1 (2) | N1—C3—C10—C15 | −169.7 (2) |
C16—N2—C1—C4 | −58.6 (3) | C2—C3—C10—C15 | 8.4 (4) |
N1—N2—C1—C2 | −10.5 (3) | C15—C10—C11—C12 | −0.1 (4) |
C16—N2—C1—C2 | −179.1 (2) | C3—C10—C11—C12 | −179.8 (2) |
N2—C1—C2—C3 | 9.2 (2) | C10—C11—C12—C13 | 0.6 (4) |
C4—C1—C2—C3 | −111.5 (2) | C11—C12—C13—C14 | −0.4 (4) |
N2—N1—C3—C10 | 178.0 (2) | C11—C12—C13—Br2 | 176.76 (19) |
N2—N1—C3—C2 | −0.3 (3) | C12—C13—C14—C15 | −0.3 (4) |
C1—C2—C3—N1 | −6.1 (3) | Br2—C13—C14—C15 | −177.42 (19) |
C1—C2—C3—C10 | 175.7 (2) | C13—C14—C15—C10 | 0.8 (4) |
N2—C1—C4—C9 | −34.0 (3) | C11—C10—C15—C14 | −0.7 (4) |
C2—C1—C4—C9 | 79.5 (3) | C3—C10—C15—C14 | 179.1 (2) |
N2—C1—C4—C5 | 148.6 (2) | N1—N2—C16—C17 | 178.2 (2) |
C2—C1—C4—C5 | −98.0 (3) | C1—N2—C16—C17 | −13.9 (4) |
C9—C4—C5—C6 | −0.2 (4) | N1—N2—C16—C21 | −1.9 (3) |
C1—C4—C5—C6 | 177.3 (2) | C1—N2—C16—C21 | 165.9 (2) |
C4—C5—C6—C7 | 0.4 (4) | N2—C16—C17—C18 | 179.0 (2) |
C5—C6—C7—C8 | 0.2 (4) | C21—C16—C17—C18 | −0.8 (4) |
C5—C6—C7—Br1 | 179.2 (2) | C16—C17—C18—C19 | −0.3 (4) |
C6—C7—C8—C9 | −1.1 (4) | C17—C18—C19—C20 | 0.9 (4) |
Br1—C7—C8—C9 | 179.9 (2) | C18—C19—C20—C21 | −0.3 (4) |
C7—C8—C9—C4 | 1.3 (4) | C19—C20—C21—C16 | −0.8 (4) |
C5—C4—C9—C8 | −0.6 (4) | N2—C16—C21—C20 | −178.4 (2) |
C1—C4—C9—C8 | −178.1 (2) | C17—C16—C21—C20 | 1.4 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···N1i | 0.95 | 2.58 | 3.374 (3) | 141 |
C20—H20···Br1ii | 0.95 | 2.92 | 3.768 (2) | 148 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) x, y−1, z. |
Experimental details
Crystal data | |
Chemical formula | C21H16Br2N2 |
Mr | 456.18 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 100 |
a, b, c (Å) | 10.5815 (3), 11.2119 (3), 15.4569 (4) |
V (Å3) | 1833.79 (9) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 4.43 |
Crystal size (mm) | 0.35 × 0.15 × 0.08 |
Data collection | |
Diffractometer | Bruker SMART APEX diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.537, 0.746 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 17504, 4201, 3753 |
Rint | 0.044 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.052, 1.02 |
No. of reflections | 4201 |
No. of parameters | 226 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.60, −0.40 |
Absolute structure | Flack (1983), 1804 Friedel pairs |
Absolute structure parameter | 0.003 (7) |
Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 2006), publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···N1i | 0.95 | 2.58 | 3.374 (3) | 141 |
C20—H20···Br1ii | 0.95 | 2.92 | 3.768 (2) | 148 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) x, y−1, z. |
Footnotes
‡Additional correspondence author, e-mail: yathirajan@hotmail.com.
Acknowledgements
SS thanks Mangalore University and the UGC SAP for financial assistance for the purchase of chemicals. HSY thanks the University of Mysore for the sanction of sabbatical leave
References
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Derivatives of pyrazoline possess a range of pharmacological activities, having, for example, anti-tumour, anti-microbial, and anti-tubercular activities (Hes et al., 1978; Amir et al., 2008). Further, some of these compounds also have anti-inflammatory, anti-diabetic, anaesthetic, analgesic and DPPH scavenging properties (Sarojini et al., 2010). In continuation of previous structural studies of pyrazoline derivatives (Fun et al., 2010, Yathirajan et al., 2007), the title compound, (I), was synthesised and its crystal structure determined.
The structure analysis of (I) shows the C1 centre to have an S configuration, Fig. 1. The conformation of the central pyrazole ring is an envelope on the C1 atom as defined by the ring-puckering parameters of q2 = 0.101 (3) Å and φ2 = 251.7 (14) ° (Cremer & Pople, 1975). That being stated, the maximum deviations from the five atoms of the ring are 0.052 (2) and -0.064 (3) Å for the N2 and C1 atoms, respectively; the r.m.s. deviation = 0.0450 Å. The N2- and C3-bound benzene rings are approximately co-planar with the central ring as seen in the dihedral angles formed between their respective least-squares planes and that through the pyrazole ring of 7.73 (13) and 11.00 (13) °; the dihedral angle between these benzene rings is 4.32 (12) °. By contrast, the C1-bound benzene ring is almost orthogonal to the remaining molecule with a dihedral angle of 79.53 (13) ° formed between it and the pyrazole ring. To a first approximation, the overall conformation in (I) resembles that in the analogous 1,3,5-triphenyl-2-pyrazoline "parent" compound although the deviations from planarity are slightly greater in the literature structure (Foces-Foces et al., 2001). Further, the N1–N2 [1.369 (3) Å] and N1═C3 [1.291 (3) Å] bond distances in (I) are comparable to the equivalent distances in 1,3,5-triphenyl-2-pyrazoline of 1.387 (5) and 1.285 (7) Å, respectively.
The molecules are consolidated into a 3-D network by C–H···N and C—H···Br contacts, Fig. 2 and Table 1.