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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

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

(Received 19 October 2010; accepted 27 October 2010; online 31 October 2010)

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 ππ 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[Ragavan, R. V., Vijayakumar, V. & Kumari, N. S. (2009). Eur. J. Med. Chem. 44, 3852-3857.], 2010[Ragavan, R. V., Vijayakumar, V. & Kumari, N. S. (2010). Eur. J. Med. Chem. 45, 1173-1180.]). For a related structure, see: Xiong et al. (2007[Xiong, Y., Gao, W.-Y., Deng, K.-Z., Chen, H.-X. & Wang, S.-J. (2007). Acta Cryst. E63, o333-o334.]). For the stability of the temperature controller used for data collection, see: Cosier & Glazer (1986[Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105-107.]).

[Scheme 1]

Experimental

Crystal data
  • C9H14N2O

  • Mr = 166.22

  • Monoclinic, P 21 /c

  • a = 12.8078 (2) Å

  • b = 6.7758 (1) Å

  • c = 10.7096 (2) Å

  • β = 111.620 (1)°

  • V = 864.03 (2) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 100 K

  • 0.54 × 0.24 × 0.11 mm

Data collection
  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.956, Tmax = 0.991

  • 6990 measured reflections

  • 1680 independent reflections

  • 1474 reflections with I > 2σ(I)

  • Rint = 0.026

Refinement
  • R[F2 > 2σ(F2)] = 0.037

  • wR(F2) = 0.095

  • S = 1.05

  • 1680 reflections

  • 117 parameters

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

  • Δρmax = 0.25 e Å−3

  • Δρmin = −0.25 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA 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+{\script{1\over 2}}, z+{\script{1\over 2}}].

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

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 ππ interactions [Cg1···Cg1iii = 3.5684 (8) Å; Cg1 is centroid of N1–N2–C1–C8–C9 ring; (iii) 1 - x, 1 - y, 1 - z].

Related literature top

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 top

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.

Refinement top

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].

Structure description top

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 ππ interactions [Cg1···Cg1iii = 3.5684 (8) Å; Cg1 is centroid of N1–N2–C1–C8–C9 ring; (iii) 1 - x, 1 - y, 1 - z].

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).

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 with atom labels and 50% probability ellipsoids for non-H atoms.
[Figure 2] Fig. 2. The crystal packing of title compound, viewed down b axis, showing the molecules are linked into planes parallel to the bc plane. Intermolecular hydrogen bonds are shown as dashed lines.
4,5,6,7,8,9-Hexahydro-2H-cycloocta[c]pyrazol-1-ium-3-olate top
Crystal data top
C9H14N2OF(000) = 360
Mr = 166.22Dx = 1.278 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 3802 reflections
a = 12.8078 (2) Åθ = 3.5–30.1°
b = 6.7758 (1) ŵ = 0.09 mm1
c = 10.7096 (2) ÅT = 100 K
β = 111.620 (1)°Plate, colourless
V = 864.03 (2) Å30.54 × 0.24 × 0.11 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
1680 independent reflections
Radiation source: fine-focus sealed tube1474 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.026
φ and ω scansθmax = 26.0°, θmin = 1.7°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
h = 1515
Tmin = 0.956, Tmax = 0.991k = 88
6990 measured reflectionsl = 1312
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) = 0.095H 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 parametersΔρmax = 0.25 e Å3
0 restraintsΔρmin = 0.25 e Å3
Crystal data top
C9H14N2OV = 864.03 (2) Å3
Mr = 166.22Z = 4
Monoclinic, P21/cMo Kα radiation
a = 12.8078 (2) ŵ = 0.09 mm1
b = 6.7758 (1) ÅT = 100 K
c = 10.7096 (2) Å0.54 × 0.24 × 0.11 mm
β = 111.620 (1)°
Data collection top
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 = 0.991Rint = 0.026
6990 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0370 restraints
wR(F2) = 0.095H atoms treated by a mixture of independent and constrained refinement
S = 1.05Δρmax = 0.25 e Å3
1680 reflectionsΔρmin = 0.25 e Å3
117 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
O10.41579 (8)0.06094 (13)0.31883 (8)0.0190 (2)
N10.44456 (9)0.21181 (16)0.52370 (10)0.0160 (3)
N20.41423 (9)0.38447 (16)0.56789 (11)0.0154 (3)
C10.34257 (10)0.48051 (18)0.46046 (12)0.0149 (3)
C20.28502 (11)0.66563 (19)0.47482 (13)0.0177 (3)
H2A0.27110.74760.39610.021*
H2B0.33350.73840.55250.021*
C30.17257 (11)0.6209 (2)0.49123 (12)0.0189 (3)
H3A0.18830.57340.58180.023*
H3B0.13060.74300.48070.023*
C40.09909 (11)0.4691 (2)0.39200 (12)0.0185 (3)
H4A0.02950.45550.40750.022*
H4B0.13710.34260.41130.022*
C50.07002 (11)0.5164 (2)0.24164 (12)0.0191 (3)
H5A0.01050.50250.19540.023*
H5B0.08880.65340.23390.023*
C60.12881 (11)0.38840 (19)0.16907 (12)0.0189 (3)
H6A0.09050.40650.07310.023*
H6B0.12020.25100.18890.023*
C70.25452 (11)0.42986 (19)0.20469 (12)0.0177 (3)
H7A0.27950.35810.14240.021*
H7B0.26400.56950.19180.021*
C80.32877 (10)0.37496 (19)0.34518 (12)0.0153 (3)
C90.39626 (10)0.20329 (18)0.38724 (12)0.0150 (3)
H1N10.4969 (14)0.125 (3)0.5823 (17)0.030 (4)*
H1N20.4229 (14)0.397 (3)0.6572 (19)0.037 (5)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0272 (5)0.0181 (5)0.0123 (4)0.0062 (4)0.0082 (4)0.0006 (3)
N10.0201 (6)0.0158 (5)0.0122 (5)0.0031 (4)0.0061 (4)0.0007 (4)
N20.0181 (6)0.0167 (5)0.0122 (5)0.0012 (4)0.0065 (4)0.0012 (4)
C10.0149 (6)0.0163 (6)0.0150 (6)0.0015 (5)0.0072 (5)0.0013 (5)
C20.0214 (7)0.0155 (6)0.0166 (6)0.0001 (5)0.0076 (5)0.0017 (5)
C30.0204 (7)0.0207 (7)0.0165 (6)0.0025 (5)0.0078 (5)0.0021 (5)
C40.0179 (7)0.0212 (7)0.0182 (6)0.0003 (5)0.0090 (5)0.0014 (5)
C50.0179 (7)0.0217 (7)0.0163 (7)0.0025 (5)0.0045 (5)0.0006 (5)
C60.0223 (7)0.0203 (7)0.0130 (6)0.0034 (5)0.0051 (5)0.0004 (5)
C70.0227 (7)0.0192 (6)0.0126 (6)0.0053 (5)0.0082 (5)0.0035 (5)
C80.0165 (6)0.0168 (6)0.0144 (6)0.0001 (5)0.0078 (5)0.0012 (5)
C90.0168 (6)0.0172 (6)0.0118 (6)0.0001 (5)0.0061 (5)0.0011 (5)
Geometric parameters (Å, º) top
O1—C91.2902 (15)C4—C51.5467 (17)
N1—C91.3622 (16)C4—H4A0.9700
N1—N21.3708 (15)C4—H4B0.9700
N1—H1N10.939 (18)C5—C61.5343 (17)
N2—C11.3459 (16)C5—H5A0.9700
N2—H1N20.925 (19)C5—H5B0.9700
C1—C81.3807 (17)C6—C71.5377 (18)
C1—C21.4912 (17)C6—H6A0.9700
C2—C31.5438 (17)C6—H6B0.9700
C2—H2A0.9700C7—C81.5007 (17)
C2—H2B0.9700C7—H7A0.9700
C3—C41.5283 (18)C7—H7B0.9700
C3—H3A0.9700C8—C91.4199 (17)
C3—H3B0.9700
C9—N1—N2109.39 (10)H4A—C4—H4B107.4
C9—N1—H1N1128.4 (10)C6—C5—C4115.83 (11)
N2—N1—H1N1121.9 (10)C6—C5—H5A108.3
C1—N2—N1107.96 (10)C4—C5—H5A108.3
C1—N2—H1N2128.7 (11)C6—C5—H5B108.3
N1—N2—H1N2119.5 (11)C4—C5—H5B108.3
N2—C1—C8109.65 (11)H5A—C5—H5B107.4
N2—C1—C2121.73 (11)C5—C6—C7115.82 (11)
C8—C1—C2128.51 (11)C5—C6—H6A108.3
C1—C2—C3111.34 (10)C7—C6—H6A108.3
C1—C2—H2A109.4C5—C6—H6B108.3
C3—C2—H2A109.4C7—C6—H6B108.3
C1—C2—H2B109.4H6A—C6—H6B107.4
C3—C2—H2B109.4C8—C7—C6114.98 (10)
H2A—C2—H2B108.0C8—C7—H7A108.5
C4—C3—C2114.47 (10)C6—C7—H7A108.5
C4—C3—H3A108.6C8—C7—H7B108.5
C2—C3—H3A108.6C6—C7—H7B108.5
C4—C3—H3B108.6H7A—C7—H7B107.5
C2—C3—H3B108.6C1—C8—C9106.16 (11)
H3A—C3—H3B107.6C1—C8—C7126.38 (11)
C3—C4—C5115.79 (11)C9—C8—C7127.44 (11)
C3—C4—H4A108.3O1—C9—N1122.31 (11)
C5—C4—H4A108.3O1—C9—C8130.92 (11)
C3—C4—H4B108.3N1—C9—C8106.76 (11)
C5—C4—H4B108.3
C9—N1—N2—C12.98 (13)C2—C1—C8—C9175.54 (12)
N1—N2—C1—C82.13 (13)N2—C1—C8—C7178.99 (11)
N1—N2—C1—C2174.25 (11)C2—C1—C8—C72.9 (2)
N2—C1—C2—C389.09 (14)C6—C7—C8—C177.60 (16)
C8—C1—C2—C386.55 (15)C6—C7—C8—C9100.55 (14)
C1—C2—C3—C446.15 (14)N2—N1—C9—O1176.18 (11)
C2—C3—C4—C555.64 (15)N2—N1—C9—C82.61 (13)
C3—C4—C5—C6108.08 (13)C1—C8—C9—O1177.37 (13)
C4—C5—C6—C772.87 (15)C7—C8—C9—O14.2 (2)
C5—C6—C7—C868.15 (15)C1—C8—C9—N11.29 (13)
N2—C1—C8—C90.52 (14)C7—C8—C9—N1177.16 (11)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N1···O1i0.938 (19)1.757 (19)2.6900 (14)173.0 (19)
N2—H1N2···O1ii0.925 (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 formulaC9H14N2O
Mr166.22
Crystal system, space groupMonoclinic, P21/c
Temperature (K)100
a, b, c (Å)12.8078 (2), 6.7758 (1), 10.7096 (2)
β (°) 111.620 (1)
V3)864.03 (2)
Z4
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.54 × 0.24 × 0.11
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.956, 0.991
No. of measured, independent and
observed [I > 2σ(I)] reflections
6990, 1680, 1474
Rint0.026
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.095, 1.05
No. of reflections1680
No. of parameters117
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.25, 0.25

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···O1i0.938 (19)1.757 (19)2.6900 (14)173.0 (19)
N2—H1N2···O1ii0.925 (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.
 

Footnotes

Thomson Reuters ResearcherID: A-3561-2009.

§Thomson Reuters ResearcherID: A-5523-2009.

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

First citationBruker (2009). 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 citationRagavan, R. V., Vijayakumar, V. & Kumari, N. S. (2009). Eur. J. Med. Chem. 44, 3852–3857.  PubMed CAS Google Scholar
First citationRagavan, R. V., Vijayakumar, V. & Kumari, N. S. (2010). Eur. J. Med. Chem. 45, 1173–1180.  Web of Science CrossRef CAS 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
First citationXiong, 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

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.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds