organic compounds
4,5,6,7,8,9-Hexahydro-2H-cycloocta[c]pyrazol-1-ium-3-olate
aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and bOrganic Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632 014, India
*Correspondence e-mail: hkfun@usm.my
The title compound, C9H14N2O, exists in the zwitterionic form in the crystal. The cyclooctane ring adopts a twisted boat-chair conformation. In the crystal, intermolecular N—H⋯O hydrogen bonds link the molecules into sheets lying parallel to the bc plane. The structure is also stabilized by π–π interactions, with a centroid-to-centroid distance of 3.5684 (8) Å.
Related literature
For pyrazole derivatives and their microbial activities, see: Ragavan et al. (2009, 2010). For a related structure, see: Xiong et al. (2007). For the stability of the temperature controller used for data collection, see: Cosier & Glazer (1986).
Experimental
Crystal data
|
Refinement
|
Data collection: APEX2 (Bruker, 2009); cell SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009).
Supporting information
https://doi.org/10.1107/S1600536810043904/fj2356sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810043904/fj2356Isup2.hkl
The compound has been synthesized using the method available in the literature Ragavan et al., (2010) and recrystallized using the ethanol–chloroform 1:1 mixture. Yield: 74%, m.p. 221.6–228.8 °C.
The N-bound H atoms were located from difference Fourier map and refined freely. The rest of H atoms were positioned geometrically [C—H = 0.97 Å] and refined using a riding model [Uiso(H) = 1.2Ueq].
Antibacterial and antifungal activities of the azoles are most widely studied and some of them are in clinical practice as anti-microbial agents. However, the azole-resistant strains led to the development of new antimicrobial compounds. In particular pyrazole derivatives are extensively studied and used as antimicrobial agents. Pyrazole is an important class of
and many pyrazole derivatives are reported to have a broad spectrum of biological properties such as anti-inflammatory, antifungal, herbicidal, anti-tumour, cytotoxic, molecular modelling and antiviral activities. Pyrazole derivatives also act as antiangiogenic agents, A3 adenosine receptor antagonists, neuropeptide YY5 receptor antagonists, kinase inhibitor for treatment of type 2 diabetes, hyperlipidemia, obesity, and thrombopiotinmimetics. Recently urea derivatives of pyrazoles have been reported as potent inhibitors of p38 kinase. Since the high of halogens (particularly chlorine and fluorine) in the aromatic part of the drug molecules play an important role in enhancing their biological activity, we are interested to have 4-fluoro or 4-chloro substitution in the aryls of 1,5-diaryl pyrazoles. As part of our on-going research aiming on the synthesis of new antimicrobial compounds, we have reported the synthesis of novel pyrazole derivatives and their microbial activities (Ragavan et al., 2009, 2010).The title compound exists in an zwitterionic form (Fig. 1). The cyclooctane ring adopts a twisted boat-chair conformation which similar to Xiong et al. (2007). In the π–π interactions [Cg1···Cg1iii = 3.5684 (8) Å; Cg1 is centroid of N1–N2–C1–C8–C9 ring; (iii) 1 - x, 1 - y, 1 - z].
intermolecular N1—H1N1···O1 and N2—H1N2···O1 hydrogen bonds link the molecules into planes parallel to the bc plane (Fig. 2). The structure is stabilized by theFor pyrazole derivatives and their microbial activities, see: Ragavan et al. (2009, 2010). For a related structure, see: Xiong et al. (2007). For the stability of the temperature controller used for data collection, see: Cosier & Glazer (1986).
Data collection: APEX2 (Bruker, 2009); cell
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).C9H14N2O | F(000) = 360 |
Mr = 166.22 | Dx = 1.278 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 3802 reflections |
a = 12.8078 (2) Å | θ = 3.5–30.1° |
b = 6.7758 (1) Å | µ = 0.09 mm−1 |
c = 10.7096 (2) Å | T = 100 K |
β = 111.620 (1)° | Plate, colourless |
V = 864.03 (2) Å3 | 0.54 × 0.24 × 0.11 mm |
Z = 4 |
Bruker SMART APEXII CCD area-detector diffractometer | 1680 independent reflections |
Radiation source: fine-focus sealed tube | 1474 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.026 |
φ and ω scans | θmax = 26.0°, θmin = 1.7° |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | h = −15→15 |
Tmin = 0.956, Tmax = 0.991 | k = −8→8 |
6990 measured reflections | l = −13→12 |
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)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.095 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.047P)2 + 0.3516P] where P = (Fo2 + 2Fc2)/3 |
1680 reflections | (Δ/σ)max < 0.001 |
117 parameters | Δρmax = 0.25 e Å−3 |
0 restraints | Δρmin = −0.25 e Å−3 |
C9H14N2O | V = 864.03 (2) Å3 |
Mr = 166.22 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 12.8078 (2) Å | µ = 0.09 mm−1 |
b = 6.7758 (1) Å | T = 100 K |
c = 10.7096 (2) Å | 0.54 × 0.24 × 0.11 mm |
β = 111.620 (1)° |
Bruker SMART APEXII CCD area-detector diffractometer | 1680 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | 1474 reflections with I > 2σ(I) |
Tmin = 0.956, Tmax = 0.991 | Rint = 0.026 |
6990 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.095 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.25 e Å−3 |
1680 reflections | Δρmin = −0.25 e Å−3 |
117 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.41579 (8) | 0.06094 (13) | 0.31883 (8) | 0.0190 (2) | |
N1 | 0.44456 (9) | 0.21181 (16) | 0.52370 (10) | 0.0160 (3) | |
N2 | 0.41423 (9) | 0.38447 (16) | 0.56789 (11) | 0.0154 (3) | |
C1 | 0.34257 (10) | 0.48051 (18) | 0.46046 (12) | 0.0149 (3) | |
C2 | 0.28502 (11) | 0.66563 (19) | 0.47482 (13) | 0.0177 (3) | |
H2A | 0.2711 | 0.7476 | 0.3961 | 0.021* | |
H2B | 0.3335 | 0.7384 | 0.5525 | 0.021* | |
C3 | 0.17257 (11) | 0.6209 (2) | 0.49123 (12) | 0.0189 (3) | |
H3A | 0.1883 | 0.5734 | 0.5818 | 0.023* | |
H3B | 0.1306 | 0.7430 | 0.4807 | 0.023* | |
C4 | 0.09909 (11) | 0.4691 (2) | 0.39200 (12) | 0.0185 (3) | |
H4A | 0.0295 | 0.4555 | 0.4075 | 0.022* | |
H4B | 0.1371 | 0.3426 | 0.4113 | 0.022* | |
C5 | 0.07002 (11) | 0.5164 (2) | 0.24164 (12) | 0.0191 (3) | |
H5A | −0.0105 | 0.5025 | 0.1954 | 0.023* | |
H5B | 0.0888 | 0.6534 | 0.2339 | 0.023* | |
C6 | 0.12881 (11) | 0.38840 (19) | 0.16907 (12) | 0.0189 (3) | |
H6A | 0.0905 | 0.4065 | 0.0731 | 0.023* | |
H6B | 0.1202 | 0.2510 | 0.1889 | 0.023* | |
C7 | 0.25452 (11) | 0.42986 (19) | 0.20469 (12) | 0.0177 (3) | |
H7A | 0.2795 | 0.3581 | 0.1424 | 0.021* | |
H7B | 0.2640 | 0.5695 | 0.1918 | 0.021* | |
C8 | 0.32877 (10) | 0.37496 (19) | 0.34518 (12) | 0.0153 (3) | |
C9 | 0.39626 (10) | 0.20329 (18) | 0.38724 (12) | 0.0150 (3) | |
H1N1 | 0.4969 (14) | 0.125 (3) | 0.5823 (17) | 0.030 (4)* | |
H1N2 | 0.4229 (14) | 0.397 (3) | 0.6572 (19) | 0.037 (5)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0272 (5) | 0.0181 (5) | 0.0123 (4) | 0.0062 (4) | 0.0082 (4) | 0.0006 (3) |
N1 | 0.0201 (6) | 0.0158 (5) | 0.0122 (5) | 0.0031 (4) | 0.0061 (4) | 0.0007 (4) |
N2 | 0.0181 (6) | 0.0167 (5) | 0.0122 (5) | 0.0012 (4) | 0.0065 (4) | −0.0012 (4) |
C1 | 0.0149 (6) | 0.0163 (6) | 0.0150 (6) | −0.0015 (5) | 0.0072 (5) | 0.0013 (5) |
C2 | 0.0214 (7) | 0.0155 (6) | 0.0166 (6) | −0.0001 (5) | 0.0076 (5) | −0.0017 (5) |
C3 | 0.0204 (7) | 0.0207 (7) | 0.0165 (6) | 0.0025 (5) | 0.0078 (5) | −0.0021 (5) |
C4 | 0.0179 (7) | 0.0212 (7) | 0.0182 (6) | 0.0003 (5) | 0.0090 (5) | −0.0014 (5) |
C5 | 0.0179 (7) | 0.0217 (7) | 0.0163 (7) | 0.0025 (5) | 0.0045 (5) | −0.0006 (5) |
C6 | 0.0223 (7) | 0.0203 (7) | 0.0130 (6) | 0.0034 (5) | 0.0051 (5) | 0.0004 (5) |
C7 | 0.0227 (7) | 0.0192 (6) | 0.0126 (6) | 0.0053 (5) | 0.0082 (5) | 0.0035 (5) |
C8 | 0.0165 (6) | 0.0168 (6) | 0.0144 (6) | 0.0001 (5) | 0.0078 (5) | 0.0012 (5) |
C9 | 0.0168 (6) | 0.0172 (6) | 0.0118 (6) | −0.0001 (5) | 0.0061 (5) | 0.0011 (5) |
O1—C9 | 1.2902 (15) | C4—C5 | 1.5467 (17) |
N1—C9 | 1.3622 (16) | C4—H4A | 0.9700 |
N1—N2 | 1.3708 (15) | C4—H4B | 0.9700 |
N1—H1N1 | 0.939 (18) | C5—C6 | 1.5343 (17) |
N2—C1 | 1.3459 (16) | C5—H5A | 0.9700 |
N2—H1N2 | 0.925 (19) | C5—H5B | 0.9700 |
C1—C8 | 1.3807 (17) | C6—C7 | 1.5377 (18) |
C1—C2 | 1.4912 (17) | C6—H6A | 0.9700 |
C2—C3 | 1.5438 (17) | C6—H6B | 0.9700 |
C2—H2A | 0.9700 | C7—C8 | 1.5007 (17) |
C2—H2B | 0.9700 | C7—H7A | 0.9700 |
C3—C4 | 1.5283 (18) | C7—H7B | 0.9700 |
C3—H3A | 0.9700 | C8—C9 | 1.4199 (17) |
C3—H3B | 0.9700 | ||
C9—N1—N2 | 109.39 (10) | H4A—C4—H4B | 107.4 |
C9—N1—H1N1 | 128.4 (10) | C6—C5—C4 | 115.83 (11) |
N2—N1—H1N1 | 121.9 (10) | C6—C5—H5A | 108.3 |
C1—N2—N1 | 107.96 (10) | C4—C5—H5A | 108.3 |
C1—N2—H1N2 | 128.7 (11) | C6—C5—H5B | 108.3 |
N1—N2—H1N2 | 119.5 (11) | C4—C5—H5B | 108.3 |
N2—C1—C8 | 109.65 (11) | H5A—C5—H5B | 107.4 |
N2—C1—C2 | 121.73 (11) | C5—C6—C7 | 115.82 (11) |
C8—C1—C2 | 128.51 (11) | C5—C6—H6A | 108.3 |
C1—C2—C3 | 111.34 (10) | C7—C6—H6A | 108.3 |
C1—C2—H2A | 109.4 | C5—C6—H6B | 108.3 |
C3—C2—H2A | 109.4 | C7—C6—H6B | 108.3 |
C1—C2—H2B | 109.4 | H6A—C6—H6B | 107.4 |
C3—C2—H2B | 109.4 | C8—C7—C6 | 114.98 (10) |
H2A—C2—H2B | 108.0 | C8—C7—H7A | 108.5 |
C4—C3—C2 | 114.47 (10) | C6—C7—H7A | 108.5 |
C4—C3—H3A | 108.6 | C8—C7—H7B | 108.5 |
C2—C3—H3A | 108.6 | C6—C7—H7B | 108.5 |
C4—C3—H3B | 108.6 | H7A—C7—H7B | 107.5 |
C2—C3—H3B | 108.6 | C1—C8—C9 | 106.16 (11) |
H3A—C3—H3B | 107.6 | C1—C8—C7 | 126.38 (11) |
C3—C4—C5 | 115.79 (11) | C9—C8—C7 | 127.44 (11) |
C3—C4—H4A | 108.3 | O1—C9—N1 | 122.31 (11) |
C5—C4—H4A | 108.3 | O1—C9—C8 | 130.92 (11) |
C3—C4—H4B | 108.3 | N1—C9—C8 | 106.76 (11) |
C5—C4—H4B | 108.3 | ||
C9—N1—N2—C1 | 2.98 (13) | C2—C1—C8—C9 | −175.54 (12) |
N1—N2—C1—C8 | −2.13 (13) | N2—C1—C8—C7 | 178.99 (11) |
N1—N2—C1—C2 | 174.25 (11) | C2—C1—C8—C7 | 2.9 (2) |
N2—C1—C2—C3 | −89.09 (14) | C6—C7—C8—C1 | −77.60 (16) |
C8—C1—C2—C3 | 86.55 (15) | C6—C7—C8—C9 | 100.55 (14) |
C1—C2—C3—C4 | −46.15 (14) | N2—N1—C9—O1 | 176.18 (11) |
C2—C3—C4—C5 | −55.64 (15) | N2—N1—C9—C8 | −2.61 (13) |
C3—C4—C5—C6 | 108.08 (13) | C1—C8—C9—O1 | −177.37 (13) |
C4—C5—C6—C7 | −72.87 (15) | C7—C8—C9—O1 | 4.2 (2) |
C5—C6—C7—C8 | 68.15 (15) | C1—C8—C9—N1 | 1.29 (13) |
N2—C1—C8—C9 | 0.52 (14) | C7—C8—C9—N1 | −177.16 (11) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N1···O1i | 0.938 (19) | 1.757 (19) | 2.6900 (14) | 173.0 (19) |
N2—H1N2···O1ii | 0.925 (19) | 1.789 (19) | 2.7056 (14) | 170.1 (18) |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) x, −y+1/2, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C9H14N2O |
Mr | 166.22 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 100 |
a, b, c (Å) | 12.8078 (2), 6.7758 (1), 10.7096 (2) |
β (°) | 111.620 (1) |
V (Å3) | 864.03 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.54 × 0.24 × 0.11 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 2009) |
Tmin, Tmax | 0.956, 0.991 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6990, 1680, 1474 |
Rint | 0.026 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.095, 1.05 |
No. of reflections | 1680 |
No. of parameters | 117 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.25, −0.25 |
Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N1···O1i | 0.938 (19) | 1.757 (19) | 2.6900 (14) | 173.0 (19) |
N2—H1N2···O1ii | 0.925 (19) | 1.789 (19) | 2.7056 (14) | 170.1 (18) |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) x, −y+1/2, z+1/2. |
Acknowledgements
HKF and CSY thank Universiti Sains Malaysia (USM) for a Research University Grant (No. 1001/PFIZIK/811160). VV is grateful to DST-India for funding through the Young Scientist Scheme (Fast Track Proposal).
References
Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107. CrossRef CAS Web of Science IUCr Journals Google Scholar
Ragavan, R. V., Vijayakumar, V. & Kumari, N. S. (2009). Eur. J. Med. Chem. 44, 3852–3857. PubMed CAS Google Scholar
Ragavan, R. V., Vijayakumar, V. & Kumari, N. S. (2010). Eur. J. Med. Chem. 45, 1173–1180. Web of Science CrossRef CAS PubMed Google Scholar
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Xiong, Y., Gao, W.-Y., Deng, K.-Z., Chen, H.-X. & Wang, S.-J. (2007). Acta Cryst. E63, o333–o334. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
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Antibacterial and antifungal activities of the azoles are most widely studied and some of them are in clinical practice as anti-microbial agents. However, the azole-resistant strains led to the development of new antimicrobial compounds. In particular pyrazole derivatives are extensively studied and used as antimicrobial agents. Pyrazole is an important class of heterocyclic compounds and many pyrazole derivatives are reported to have a broad spectrum of biological properties such as anti-inflammatory, antifungal, herbicidal, anti-tumour, cytotoxic, molecular modelling and antiviral activities. Pyrazole derivatives also act as antiangiogenic agents, A3 adenosine receptor antagonists, neuropeptide YY5 receptor antagonists, kinase inhibitor for treatment of type 2 diabetes, hyperlipidemia, obesity, and thrombopiotinmimetics. Recently urea derivatives of pyrazoles have been reported as potent inhibitors of p38 kinase. Since the high electronegativity of halogens (particularly chlorine and fluorine) in the aromatic part of the drug molecules play an important role in enhancing their biological activity, we are interested to have 4-fluoro or 4-chloro substitution in the aryls of 1,5-diaryl pyrazoles. As part of our on-going research aiming on the synthesis of new antimicrobial compounds, we have reported the synthesis of novel pyrazole derivatives and their microbial activities (Ragavan et al., 2009, 2010).
The title compound exists in an zwitterionic form (Fig. 1). The cyclooctane ring adopts a twisted boat-chair conformation which similar to Xiong et al. (2007). In the crystal structure, intermolecular N1—H1N1···O1 and N2—H1N2···O1 hydrogen bonds link the molecules into planes parallel to the bc plane (Fig. 2). The structure is stabilized by the π–π interactions [Cg1···Cg1iii = 3.5684 (8) Å; Cg1 is centroid of N1–N2–C1–C8–C9 ring; (iii) 1 - x, 1 - y, 1 - z].