organic compounds
1,3-Diphenyl-4,5-dihydro-1H-pyrazol-5-one
aDepartment of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB24 3UE, Scotland, bCHEMSOL, 1 Harcourt Road, Aberdeen, AB15 5NY, Scotland, cDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, and dCentro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz (FIOCRUZ), Casa Amarela, Campus de Manguinhos, Av. Brasil 4365, 21040-900 Rio de Janeiro, RJ, Brazil
*Correspondence e-mail: edward.tiekink@gmail.com
In the title pyrazolone derivative, C15H12N2O, the five-membered ring is approximately planar (r.m.s. deviation = 0.018 Å), and the N- and C-bound benzene rings are inclined to this plane [dihedral angles = 21.45 (10) and 6.96 (10)°, respectively] and form a dihedral angle of 20.42 (10)° with each other. Supramolecular layers are formed in the via C—H⋯O and C—H⋯N interactions, and these are assembled into double layers by C—H⋯π and π–π interactions between the pyrazole and C-bound benzene rings [ring centroid–centroid distance = 3.6476 (12) Å]. The double layers stack along the a axis being connected by π–π interactions between the N- and C-bound benzene rings [ring centroid–centroid distance = 3.7718 (12) Å].
Related literature
For the therapeutic importance of pyrazoles, see: Sil et al. (2005); Haddad et al. (2004). For their diverse pharmacological activities, see: Bekhit et al. (2012); Castagnolo et al. (2008); Ramajayam et al. (2010). For background to the synthesis, see: Nef (1891); Katritzky et al. (1997); Wardell et al. (2007); de Lima et al. (2010). For evaluation of tautomeric forms using NMR MO calculations and crystallography, see: Feeney et al. (1970); Hawkes et al. (1977); Freyer et al. (1983); Dardonville et al. (1998); Kleinpeter & Koch (2001); Bechtel et al. (1973a,b); Chmutova et al. (2001); Wardell et al. (2007); Gallardo et al. (2009); Ding & Zhao (2010). For a previous synthesis, see: Kimata et al. (2007). For a recently reported structure, see: Wardell et al. (2012).
Experimental
Crystal data
|
Refinement
|
Data collection: COLLECT (Hooft, 1998); cell DENZO (Otwinowski & Minor, 1997) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); 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
10.1107/S1600536812009567/hg5186sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812009567/hg5186Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536812009567/hg5186Isup3.cml
A solution of PhNHNH2 (1 mmol) and PhCOCH2CO2Et (1 mmol) in EtOH (15 ml) was refluxed for 1 h. The reaction mixture was maintained at room temperature and crystals of the titled compound were collected after 2 days, M.pt: 408–410 K: lit. value 409–411 K (Kimata et al., 2007). IR and NMR spectra are in agreement with published data (Castagnolo et al., 2008). MS—MS (M+H = 237): 209, 195, 106, 91.
The C-bound H atoms were geometrically placed (C—H = 0.95–0.99 Å) and refined as riding with Uiso(H) = 1.2Ueq(C). Owing to poor agreement one reflection, i.e. (3 1 1), was removed from the final cycles of The maximum and minimum residual electron density peaks of 0.74 and 0.20 e Å-3, respectively, were located 1.02 Å and 0.58 Å from the H8a and O1 atoms, respectively.
Pyrazoles are key structures in numerous compounds of therapeutic importance (Sil et al., 2005, Haddad et al., 2004). Compounds containing this ring system are known to display diverse pharmacological activities, for example as anti-malarial agents (Bekhit et al., 2012), anti-tuberculosis agents (Castagnolo et al., 2008), and as SARS-coronavirus protease inhibitors (Ramajayam et al., 2010).
A general route to pyrazole derivatives involves reaction of an arylhydrazine, ArNHNH2, with a β-dicarbonyl compound, R/COCH2COX.. This reaction provides initially a hydrazone derivative, RNHN=CR/CH2COX, I (Fig. 1), which can be isolated but which readily undergoes to a pyrazone derivative, II (Fig.1), (Nef, 1891; Katritzky et al., 1997; Wardell et al., 2007; de Lima et al., 2010). Equilibrium involving tautomers of II in solution have been variously studied using NMR and IR spectroscopy and ab initio calculations. (Feeney et al., 1970; Hawkes et al., 1977; Freyer et al., 1983; Dardonville et al., 1998; Kleinpeter & Koch, 2001). Crystal structures of various pyrazone compounds of forms IIa, IIb and IIc have been reported (see for example, Bechtel et al., 1973a; Bechtel et al., 1973b; Chmutova et al., 2001; Wardell et al., 2007; Gallardo et al., 2009; Ding & Zhao, 2010). In continuation of recent studies (Wardell et al., 2012), herein, the isolation the title compound [i.e. form IIc (Fig. 1)] from the reaction between PhNHNH2 and PhCOCH2CO2Et in EtOH is described as is its The same tautomer was also isolated in the reaction between PhNHNH2 and PhCOCH2CONHPh in EtOH.
In the title compound, Fig. 2, crystallography proves the IIc tautomer in the solid-state. The pyrazole ring is planar with a r.m.s. deviation for the fitted atoms of 0.018 Å; the maximum deviations from this plane are 0.015 (1) Å (for the N1 atom) and -0.015 (1) Å (C8). The N– and C-bound benzene rings are inclined to this plane forming dihedral angles of 21.45 (10) and 6.96 (10)°, respectively; the dihedral angle between the benzene rings is 20.42 (10)° consistent with a non-planar molecule.
In the π, Table 1, and π–π interactions formed between the pyrazole and C-bound benzene rings [ring centroid···centroid distance = 3.6476 (12) Å, angle of inclination of 6.96 (10)° for 1 - x, 1 - y, 2 - z]. The double layers stack along the a axis being connected by π–π interactions between the N– and C-bound benzene rings [ring centroid···centroid distance = 3.7718 (12) Å, angle of inclination of 21.45 (10)° for -x, 1 - y, 1 - z].
supramolecular layers are formed in the bc plane through C—H···O and C—H···N interactions, Fig. 3 and Table 1. Large 21-membered {···NC4H···N2CO···HC2O···HC5H} synthons are formed through these interactions. Layers are connected into double layers by C—H···For the therapeutic importance of pyrazoles, see: Sil et al. (2005); Haddad et al. (2004). For their diverse pharmacological activities, see: Bekhit et al. (2012); Castagnolo et al. (2008); Ramajayam et al. (2010). For background to the synthesis, see: Nef (1891); Katritzky et al. (1997); Wardell et al. (2007); de Lima et al. (2010). For evaluation of tautomeric forms using NMR MO calculations and crystallography, see: Feeney et al. (1970); Hawkes et al. (1977); Freyer et al. (1983); Dardonville et al. (1998); Kleinpeter & Koch (2001); Bechtel et al. (1973a,b); Chmutova et al. (2001); Wardell et al. (2007); Gallardo et al. (2009); Ding & Zhao (2010). For a previous synthesis, see: Kimata et al. (2007). For a recently reported structure, see: Wardell et al. (2012).
Data collection: COLLECT (Hooft, 1998); cell
DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); data reduction: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); 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).C15H12N2O | F(000) = 496 |
Mr = 236.27 | Dx = 1.356 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 9201 reflections |
a = 11.1823 (3) Å | θ = 2.9–27.5° |
b = 11.7503 (4) Å | µ = 0.09 mm−1 |
c = 9.6443 (2) Å | T = 120 K |
β = 113.998 (2)° | Rod, light-yellow |
V = 1157.68 (6) Å3 | 0.34 × 0.10 × 0.08 mm |
Z = 4 |
Rigaku Saturn724+ diffractometer | 2024 independent reflections |
Radiation source: Rotating Anode | 1829 reflections with I > 2σ(I) |
Confocal monochromator | Rint = 0.042 |
Detector resolution: 28.5714 pixels mm-1 | θmax = 25.0°, θmin = 2.9° |
profile data from ω–scans | h = −13→13 |
Absorption correction: multi-scan (SADABS; Sheldrick, 2007) | k = −13→12 |
Tmin = 0.790, Tmax = 1.000 | l = −11→11 |
12058 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.048 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.127 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0598P)2 + 0.8279P] where P = (Fo2 + 2Fc2)/3 |
2024 reflections | (Δ/σ)max < 0.001 |
163 parameters | Δρmax = 0.74 e Å−3 |
0 restraints | Δρmin = −0.20 e Å−3 |
C15H12N2O | V = 1157.68 (6) Å3 |
Mr = 236.27 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 11.1823 (3) Å | µ = 0.09 mm−1 |
b = 11.7503 (4) Å | T = 120 K |
c = 9.6443 (2) Å | 0.34 × 0.10 × 0.08 mm |
β = 113.998 (2)° |
Rigaku Saturn724+ diffractometer | 2024 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2007) | 1829 reflections with I > 2σ(I) |
Tmin = 0.790, Tmax = 1.000 | Rint = 0.042 |
12058 measured reflections |
R[F2 > 2σ(F2)] = 0.048 | 0 restraints |
wR(F2) = 0.127 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.74 e Å−3 |
2024 reflections | Δρmin = −0.20 e Å−3 |
163 parameters |
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 | ||
O1 | 0.22694 (13) | 0.27778 (11) | 0.57957 (14) | 0.0312 (4) | |
N1 | 0.21383 (13) | 0.47099 (12) | 0.62331 (15) | 0.0198 (4) | |
N2 | 0.24220 (13) | 0.54258 (12) | 0.74837 (15) | 0.0196 (3) | |
C1 | 0.15405 (16) | 0.51898 (14) | 0.47568 (18) | 0.0195 (4) | |
C2 | 0.16304 (18) | 0.46485 (15) | 0.35195 (19) | 0.0247 (4) | |
H2 | 0.2084 | 0.3946 | 0.3650 | 0.030* | |
C3 | 0.1051 (2) | 0.51443 (17) | 0.2092 (2) | 0.0302 (5) | |
H3 | 0.1101 | 0.4771 | 0.1243 | 0.036* | |
C4 | 0.03995 (18) | 0.61747 (16) | 0.1888 (2) | 0.0292 (5) | |
H4 | 0.0002 | 0.6507 | 0.0907 | 0.035* | |
C5 | 0.03356 (17) | 0.67148 (16) | 0.3133 (2) | 0.0272 (4) | |
H5 | −0.0094 | 0.7429 | 0.3004 | 0.033* | |
C6 | 0.08893 (17) | 0.62284 (15) | 0.4563 (2) | 0.0232 (4) | |
H6 | 0.0826 | 0.6600 | 0.5405 | 0.028* | |
C7 | 0.24708 (16) | 0.35860 (14) | 0.66481 (19) | 0.0200 (4) | |
C8 | 0.30948 (17) | 0.35961 (14) | 0.83575 (18) | 0.0202 (4) | |
H8A | 0.2618 | 0.3096 | 0.8787 | 0.024* | |
H8B | 0.4023 | 0.3357 | 0.8752 | 0.024* | |
C9 | 0.29726 (16) | 0.48130 (14) | 0.86983 (18) | 0.0187 (4) | |
C10 | 0.34323 (16) | 0.53258 (14) | 1.02117 (18) | 0.0204 (4) | |
C11 | 0.31799 (17) | 0.64722 (15) | 1.0390 (2) | 0.0231 (4) | |
H11 | 0.2693 | 0.6921 | 0.9523 | 0.028* | |
C12 | 0.36371 (18) | 0.69541 (16) | 1.1822 (2) | 0.0259 (4) | |
H12 | 0.3452 | 0.7729 | 1.1937 | 0.031* | |
C13 | 0.43659 (18) | 0.63072 (16) | 1.3092 (2) | 0.0271 (4) | |
H13 | 0.4688 | 0.6642 | 1.4073 | 0.033* | |
C14 | 0.46240 (18) | 0.51717 (16) | 1.2925 (2) | 0.0260 (4) | |
H14 | 0.5127 | 0.4731 | 1.3794 | 0.031* | |
C15 | 0.41501 (17) | 0.46785 (15) | 1.14959 (19) | 0.0225 (4) | |
H15 | 0.4315 | 0.3897 | 1.1390 | 0.027* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0396 (8) | 0.0244 (7) | 0.0291 (7) | 0.0014 (6) | 0.0134 (6) | −0.0030 (6) |
N1 | 0.0215 (7) | 0.0188 (8) | 0.0177 (7) | −0.0005 (6) | 0.0064 (6) | −0.0021 (5) |
N2 | 0.0202 (7) | 0.0191 (8) | 0.0195 (7) | −0.0009 (6) | 0.0079 (6) | −0.0019 (5) |
C1 | 0.0169 (8) | 0.0201 (9) | 0.0201 (9) | −0.0037 (6) | 0.0061 (7) | 0.0006 (7) |
C2 | 0.0271 (9) | 0.0236 (9) | 0.0244 (9) | −0.0011 (7) | 0.0113 (7) | 0.0003 (7) |
C3 | 0.0357 (11) | 0.0335 (11) | 0.0214 (9) | −0.0065 (8) | 0.0117 (8) | −0.0026 (8) |
C4 | 0.0280 (10) | 0.0302 (10) | 0.0225 (9) | −0.0072 (8) | 0.0031 (8) | 0.0067 (7) |
C5 | 0.0235 (9) | 0.0233 (9) | 0.0294 (10) | −0.0014 (7) | 0.0053 (7) | 0.0042 (7) |
C6 | 0.0216 (9) | 0.0230 (9) | 0.0243 (9) | −0.0013 (7) | 0.0086 (7) | −0.0014 (7) |
C7 | 0.0217 (9) | 0.0170 (8) | 0.0221 (9) | −0.0005 (7) | 0.0099 (7) | −0.0007 (7) |
C8 | 0.0231 (9) | 0.0174 (9) | 0.0207 (8) | 0.0006 (7) | 0.0094 (7) | 0.0010 (7) |
C9 | 0.0170 (8) | 0.0201 (9) | 0.0195 (8) | 0.0000 (6) | 0.0079 (7) | 0.0015 (7) |
C10 | 0.0191 (8) | 0.0230 (9) | 0.0214 (9) | −0.0013 (7) | 0.0106 (7) | 0.0000 (7) |
C11 | 0.0214 (9) | 0.0241 (9) | 0.0233 (9) | 0.0026 (7) | 0.0086 (7) | 0.0018 (7) |
C12 | 0.0272 (9) | 0.0235 (9) | 0.0294 (10) | 0.0012 (7) | 0.0140 (8) | −0.0040 (7) |
C13 | 0.0286 (10) | 0.0316 (11) | 0.0217 (9) | −0.0024 (8) | 0.0108 (8) | −0.0062 (7) |
C14 | 0.0273 (10) | 0.0305 (10) | 0.0199 (9) | 0.0018 (8) | 0.0093 (7) | 0.0035 (7) |
C15 | 0.0257 (9) | 0.0205 (9) | 0.0232 (9) | 0.0012 (7) | 0.0120 (7) | 0.0016 (7) |
O1—C7 | 1.216 (2) | C7—C8 | 1.506 (2) |
N1—C7 | 1.386 (2) | C8—C9 | 1.486 (2) |
N1—N2 | 1.3970 (19) | C8—H8A | 0.9900 |
N1—C1 | 1.421 (2) | C8—H8B | 0.9900 |
N2—C9 | 1.297 (2) | C9—C10 | 1.465 (2) |
C1—C2 | 1.391 (2) | C10—C15 | 1.396 (2) |
C1—C6 | 1.394 (2) | C10—C11 | 1.401 (2) |
C2—C3 | 1.389 (3) | C11—C12 | 1.384 (2) |
C2—H2 | 0.9500 | C11—H11 | 0.9500 |
C3—C4 | 1.385 (3) | C12—C13 | 1.389 (3) |
C3—H3 | 0.9500 | C12—H12 | 0.9500 |
C4—C5 | 1.386 (3) | C13—C14 | 1.388 (3) |
C4—H4 | 0.9500 | C13—H13 | 0.9500 |
C5—C6 | 1.384 (2) | C14—C15 | 1.387 (2) |
C5—H5 | 0.9500 | C14—H14 | 0.9500 |
C6—H6 | 0.9500 | C15—H15 | 0.9500 |
C7—N1—N2 | 112.61 (13) | C9—C8—H8A | 111.4 |
C7—N1—C1 | 128.99 (14) | C7—C8—H8A | 111.4 |
N2—N1—C1 | 118.38 (14) | C9—C8—H8B | 111.4 |
C9—N2—N1 | 107.64 (14) | C7—C8—H8B | 111.4 |
C2—C1—C6 | 120.06 (16) | H8A—C8—H8B | 109.3 |
C2—C1—N1 | 120.63 (15) | N2—C9—C10 | 121.10 (15) |
C6—C1—N1 | 119.29 (15) | N2—C9—C8 | 112.77 (14) |
C3—C2—C1 | 119.40 (17) | C10—C9—C8 | 126.12 (15) |
C3—C2—H2 | 120.3 | C15—C10—C11 | 119.15 (15) |
C1—C2—H2 | 120.3 | C15—C10—C9 | 120.12 (16) |
C4—C3—C2 | 120.92 (17) | C11—C10—C9 | 120.72 (15) |
C4—C3—H3 | 119.5 | C12—C11—C10 | 120.30 (16) |
C2—C3—H3 | 119.5 | C12—C11—H11 | 119.8 |
C3—C4—C5 | 119.12 (16) | C10—C11—H11 | 119.8 |
C3—C4—H4 | 120.4 | C11—C12—C13 | 120.13 (17) |
C5—C4—H4 | 120.4 | C11—C12—H12 | 119.9 |
C6—C5—C4 | 120.94 (17) | C13—C12—H12 | 119.9 |
C6—C5—H5 | 119.5 | C14—C13—C12 | 119.95 (16) |
C4—C5—H5 | 119.5 | C14—C13—H13 | 120.0 |
C5—C6—C1 | 119.52 (17) | C12—C13—H13 | 120.0 |
C5—C6—H6 | 120.2 | C13—C14—C15 | 120.21 (16) |
C1—C6—H6 | 120.2 | C13—C14—H14 | 119.9 |
O1—C7—N1 | 126.50 (15) | C15—C14—H14 | 119.9 |
O1—C7—C8 | 128.48 (15) | C14—C15—C10 | 120.24 (17) |
N1—C7—C8 | 105.00 (13) | C14—C15—H15 | 119.9 |
C9—C8—C7 | 101.91 (13) | C10—C15—H15 | 119.9 |
C7—N1—N2—C9 | 2.34 (18) | O1—C7—C8—C9 | −176.47 (18) |
C1—N1—N2—C9 | −179.20 (14) | N1—C7—C8—C9 | 2.23 (16) |
C7—N1—C1—C2 | −23.6 (3) | N1—N2—C9—C10 | 177.90 (14) |
N2—N1—C1—C2 | 158.25 (15) | N1—N2—C9—C8 | −0.70 (18) |
C7—N1—C1—C6 | 158.12 (17) | C7—C8—C9—N2 | −0.98 (18) |
N2—N1—C1—C6 | −20.0 (2) | C7—C8—C9—C10 | −179.50 (15) |
C6—C1—C2—C3 | −0.9 (3) | N2—C9—C10—C15 | −172.87 (15) |
N1—C1—C2—C3 | −179.19 (15) | C8—C9—C10—C15 | 5.5 (3) |
C1—C2—C3—C4 | 0.8 (3) | N2—C9—C10—C11 | 6.0 (2) |
C2—C3—C4—C5 | 0.3 (3) | C8—C9—C10—C11 | −175.62 (16) |
C3—C4—C5—C6 | −1.3 (3) | C15—C10—C11—C12 | 0.0 (3) |
C4—C5—C6—C1 | 1.1 (3) | C9—C10—C11—C12 | −178.90 (16) |
C2—C1—C6—C5 | 0.0 (3) | C10—C11—C12—C13 | 0.9 (3) |
N1—C1—C6—C5 | 178.26 (15) | C11—C12—C13—C14 | −0.7 (3) |
N2—N1—C7—O1 | 175.85 (16) | C12—C13—C14—C15 | −0.4 (3) |
C1—N1—C7—O1 | −2.4 (3) | C13—C14—C15—C10 | 1.2 (3) |
N2—N1—C7—C8 | −2.88 (18) | C11—C10—C15—C14 | −1.0 (3) |
C1—N1—C7—C8 | 178.87 (15) | C9—C10—C15—C14 | 177.83 (16) |
Cg1 is the centroid of the C10–C15 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8A···O1i | 0.99 | 2.36 | 3.279 (2) | 154 |
C12—H12···N2ii | 0.95 | 2.61 | 3.527 (2) | 163 |
C8—H8B···Cg1iii | 0.99 | 2.69 | 3.437 (2) | 132 |
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) x, −y+3/2, z+1/2; (iii) −x+1, −y+1, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C15H12N2O |
Mr | 236.27 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 120 |
a, b, c (Å) | 11.1823 (3), 11.7503 (4), 9.6443 (2) |
β (°) | 113.998 (2) |
V (Å3) | 1157.68 (6) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.34 × 0.10 × 0.08 |
Data collection | |
Diffractometer | Rigaku Saturn724+ |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2007) |
Tmin, Tmax | 0.790, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12058, 2024, 1829 |
Rint | 0.042 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.048, 0.127, 1.07 |
No. of reflections | 2024 |
No. of parameters | 163 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.74, −0.20 |
Computer programs: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 2006), publCIF (Westrip, 2010).
Cg1 is the centroid of the C10–C15 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8A···O1i | 0.99 | 2.36 | 3.279 (2) | 154 |
C12—H12···N2ii | 0.95 | 2.61 | 3.527 (2) | 163 |
C8—H8B···Cg1iii | 0.99 | 2.69 | 3.437 (2) | 132 |
Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) x, −y+3/2, z+1/2; (iii) −x+1, −y+1, −z+2. |
Footnotes
‡Additional correspondence author, e-mail: j.wardell@abdn.ac.uk.
Acknowledgements
The use of the EPSRC X-ray crystallographic service at the University of Southampton, England, and the valuable assistance of the staff there is gratefully acknowledged. JLW acknowledges support from CAPES (Brazil). Support from the Ministry of Higher Education, Malaysia, High-Impact Research scheme (UM.C/HIR/MOHE/SC/12) is gratefully acknowledged.
References
Bechtel, F., Gaultier, J. & Hauw, C. (1973a). Cryst. Struct. Commun. 3, 469–472. Google Scholar
Bechtel, F., Gaultier, J. & Hauw, C. (1973b). Cryst. Struct. Commun. 3, 473–476. Google Scholar
Bekhit, A. A., Hymete, A., Asfaw, H., Bekhit, A. & El-D, A. (2012). Arch. Pharm. 345, 147–154. Web of Science CrossRef CAS Google Scholar
Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Castagnolo, D., de Logu, A., Radi, M., Bechi, B., Manetti, F., Magnani, M., Supino, S., Mleddu, R., Chisu, L. & Botta, M. (2008). Bioorg. Med. Chem. 16, 8587–8591. Web of Science CrossRef PubMed CAS Google Scholar
Chmutova, G. A., Kataeva, O. N., Ahlbrecht, H., Kurbangslieva, A. R., Movchan, A. I., Lenstra, A. T. H., Geose, H. J. & Litvinov, I. A. (2001). J. Mol. Struct. 570, 215–223. Web of Science CSD CrossRef CAS Google Scholar
Dardonville, C., Elguero, J., Fernadez-Castano, C., Foces-Foces, C. & Sobrados, I. (1998). New J. Chem. pp. 1421–1430. Web of Science CSD CrossRef Google Scholar
Ding, Y.-J. & Zhao, C.-X. (2010). Acta Cryst. E66, o709. Web of Science CSD CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Feeney, J., Newman, G. A. & Pauweis, P. J. S. (1970). J. Chem. Soc. C, pp. 1842–1844. Google Scholar
Freyer, W., Koeppel, H., Radeglia, R. & Malewski, G. (1983). J. Prakt. Chem. 325, 328–350. CrossRef Web of Science Google Scholar
Gallardo, H., Girotto, E., Bortoluzzi, A. J. & Terra, G. G. (2009). Acta Cryst. E65, o2040–o2041. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Haddad, N., Salvango, A. & Busacca, C. (2004). Tetrahedron Lett. 45, 5935–5937. Web of Science CrossRef CAS Google Scholar
Hawkes, G. E., Randall, E. W., Elguero, J. & Marzin, C. J. (1977). J. Chem. Soc. Perkin Trans. II, pp. 1024–1027. CrossRef Google Scholar
Hooft, R. W. W. (1998). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Katritzky, A. R., Barczynski, P. & Ostercamp, D. L. (1997). J. Chem. Soc. Perkin Trans II, pp. 969–975. Google Scholar
Kimata, A., Nakagawa, H., Ohyama, R., Fukuuchi, T., Ohta, S., Suzuki, T. & Miyata, N. (2007). J. Med. Chem. 50, 5053–5058. Web of Science CrossRef PubMed CAS Google Scholar
Kleinpeter, E. & Koch, A. (2001). J. Phys. Org. Chem. 14, 566–576. Web of Science CrossRef CAS Google Scholar
Lima, G. M. de, Wardell, J. L. & Wardell, S. M. S. V. (2010). J. Chem. Crystallogr. 40, 213–221. Web of Science CSD CrossRef CAS Google Scholar
Nef, J. U. (1891). Justus Liebigs Ann. Chem. 266, 52–138. CrossRef Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Ramajayam, R., Tan, K.-P., Liu, H.-G. & Liang, P.-H. (2010). Bioorg. Med. Chem. 18, 7849–7854. Web of Science CrossRef CAS PubMed Google Scholar
Sheldrick, G. M. (2007). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sil, D., Kumar, R., Sharon, A., Maulik, P. R. & Rama, V. J. (2005). Tetrahedron Lett. 46, 3807–3809. Web of Science CSD CrossRef CAS Google Scholar
Wardell, S. M. S. V., Howie, A. H., Tiekink, E. R. T. & Wardell, J. L. (2012). Acta Cryst. E68, o992–o993. CSD CrossRef IUCr Journals Google Scholar
Wardell, J. L., Skakle, J. M. S., Low, J. N. & Glidewell, C. (2007). Acta Cryst. C63, o462–o467. Web of Science CSD CrossRef IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
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.
Pyrazoles are key structures in numerous compounds of therapeutic importance (Sil et al., 2005, Haddad et al., 2004). Compounds containing this ring system are known to display diverse pharmacological activities, for example as anti-malarial agents (Bekhit et al., 2012), anti-tuberculosis agents (Castagnolo et al., 2008), and as SARS-coronavirus protease inhibitors (Ramajayam et al., 2010).
A general route to pyrazole derivatives involves reaction of an arylhydrazine, ArNHNH2, with a β-dicarbonyl compound, R/COCH2COX.. This reaction provides initially a hydrazone derivative, RNHN=CR/CH2COX, I (Fig. 1), which can be isolated but which readily undergoes cyclization to a pyrazone derivative, II (Fig.1), (Nef, 1891; Katritzky et al., 1997; Wardell et al., 2007; de Lima et al., 2010). Equilibrium involving tautomers of II in solution have been variously studied using NMR and IR spectroscopy and ab initio calculations. (Feeney et al., 1970; Hawkes et al., 1977; Freyer et al., 1983; Dardonville et al., 1998; Kleinpeter & Koch, 2001). Crystal structures of various pyrazone compounds of forms IIa, IIb and IIc have been reported (see for example, Bechtel et al., 1973a; Bechtel et al., 1973b; Chmutova et al., 2001; Wardell et al., 2007; Gallardo et al., 2009; Ding & Zhao, 2010). In continuation of recent studies (Wardell et al., 2012), herein, the isolation the title compound [i.e. form IIc (Fig. 1)] from the reaction between PhNHNH2 and PhCOCH2CO2Et in EtOH is described as is its crystal structure. The same tautomer was also isolated in the reaction between PhNHNH2 and PhCOCH2CONHPh in EtOH.
In the title compound, Fig. 2, crystallography proves the IIc tautomer in the solid-state. The pyrazole ring is planar with a r.m.s. deviation for the fitted atoms of 0.018 Å; the maximum deviations from this plane are 0.015 (1) Å (for the N1 atom) and -0.015 (1) Å (C8). The N– and C-bound benzene rings are inclined to this plane forming dihedral angles of 21.45 (10) and 6.96 (10)°, respectively; the dihedral angle between the benzene rings is 20.42 (10)° consistent with a non-planar molecule.
In the crystal structure, supramolecular layers are formed in the bc plane through C—H···O and C—H···N interactions, Fig. 3 and Table 1. Large 21-membered {···NC4H···N2CO···HC2O···HC5H} synthons are formed through these interactions. Layers are connected into double layers by C—H···π, Table 1, and π–π interactions formed between the pyrazole and C-bound benzene rings [ring centroid···centroid distance = 3.6476 (12) Å, angle of inclination of 6.96 (10)° for symmetry operation 1 - x, 1 - y, 2 - z]. The double layers stack along the a axis being connected by π–π interactions between the N– and C-bound benzene rings [ring centroid···centroid distance = 3.7718 (12) Å, angle of inclination of 21.45 (10)° for symmetry operation -x, 1 - y, 1 - z].