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Volume 67 
Part 1 
Pages o151-o152  
January 2011  

Received 8 December 2010
Accepted 12 December 2010
Online 18 December 2010

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Key indicators
Single-crystal X-ray study
T = 100 K
Mean [sigma](C-C) = 0.002 Å
R = 0.044
wR = 0.119
Data-to-parameter ratio = 20.1
Details
Open access

4-Methyl-5-phenyl-1H-pyrazol-3(2H)-one

Wan-Sin Loh,a+ Hoong-Kun Fun,a*++ R. Venkat Ragavan,b V. Vijayakumarb and S. Sarveswarib

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 asymmetric unit of the title compound, C10H10N2O, contains two crystallographically independent molecules with similar geometries, which exist in the keto form. The C=O bond lengths are 1.2878 (12) Å in molecule A and 1.2890 (12) Å in molecule B, indicating that the compound undergoes enol-to-keto tautomerism during the crystallization process. In molecule A, the pyrazole ring is approximately planar [maximum deviation = 0.007 (1) Å] and forms a dihedral angle of 36.67 (6)° with the attached phenyl ring. In molecule B, the dihedral angle formed between the pyrazole ring [maximum deviation = 0.017 (1) Å] and the phenyl ring is 41.19 (6)°. In the crystal, intermolecular N-H...O hydrogen bonds link neighbouring molecules into dimers generating R22(8) ring motifs. These dimers are linked into ribbons along [101] via intermolecular N-H...O hydrogen bonds, forming R42(10) ring motifs.

Related literature

For background to pyrazole derivatives and their antimicrobial activity, see: Ragavan et al. (2009[Ragavan, R. V., Vijayakumar, V. & Sucheta Kumari, N. (2009). Eur. J. Med. Chem. 44, 3852-3857.], 2010[Ragavan, R. V., Vijayakumar, V. & Sucheta Kumari, N. (2010). Eur. J. Med. Chem. 45, 1173-1180.]). For 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 the structure of the enol form of this molecule, see: Shahani et al. (2010[Shahani, T., Fun, H.-K., Ragavan, R. V., Vijayakumar, V. & Sarveswari, S. (2010). Acta Cryst. E66, o1697-o1698.]). For other related structures, see: Loh et al. (2010a[Loh, W.-S., Fun, H.-K., Ragavan, R. V., Vijayakumar, V. & Sarveswari, S. (2010a). Acta Cryst. E66, o2925.],b[Loh, W.-S., Fun, H.-K., Ragavan, R. V., Vijayakumar, V. & Venkatesh, M. (2010b). Acta Cryst. E66, o2563-o2564.],c[Loh, W.-S., Fun, H.-K., Ragavan, R. V., Vijayakumar, V. & Venkatesh, M. (2010c). Acta Cryst. E66, o3050-o3051.]). 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.]). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986[Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105-107.]).

[Scheme 1]

Experimental

Crystal data

  • C10H10N2O

  • Mr = 174.20

  • Monoclinic, C 2/c

  • a = 25.9337 (4) Å

  • b = 10.8100 (1) Å

  • c = 14.1426 (2) Å

  • [beta] = 118.961 (1)°

  • V = 3468.98 (8) Å3

  • Z = 16

  • Mo K[alpha] radiation

  • [mu] = 0.09 mm-1

  • T = 100 K

  • 0.45 × 0.39 × 0.25 mm
Data collection

  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEXII, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.961, Tmax = 0.978

  • 36992 measured reflections

  • 5087 independent reflections

  • 4389 reflections with I > 2[sigma](I)

  • Rint = 0.036
Refinement

  • R[F2 > 2[sigma](F2)] = 0.044

  • wR(F2) = 0.119

  • S = 1.03

  • 5087 reflections

  • 253 parameters

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

  • [Delta][rho]max = 0.45 e Å-3

  • [Delta][rho]min = -0.22 e Å-3

Table 1
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
N1B-H1NB...O1Ai 0.913 (17) 1.796 (17) 2.7001 (11) 170.0 (16)
N1A-H1NA...O1B 0.935 (19) 1.78 (2) 2.6987 (14) 165.9 (16)
N2A-H2NA...O1Aii 0.93 (2) 1.768 (19) 2.6917 (12) 173.9 (17)
N2B-H2NB...O1Biii 0.934 (18) 1.752 (18) 2.6850 (13) 177.0 (16)
Symmetry codes: (i) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]; (ii) [-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z]; (iii) [-x+1, y, -z+{\script{1\over 2}}].

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

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ5074 ).

Acknowledgements

HKF and WSL thank Universiti Sains Malaysia (USM) for the Research University Grant (1001/PFIZIK/811160). WSL also thanks the Malaysian government and USM for the award of a Research Fellowship. VV is grateful to the DST-India for funding through the Young Scientist Scheme (Fast Track Proposal).

References

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.
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.  [CrossRef] [ChemPort] [ISI]
Bruker (2009). APEXII, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105-107.  [CrossRef] [ChemPort] [ISI] [details]
Loh, W.-S., Fun, H.-K., Ragavan, R. V., Vijayakumar, V. & Sarveswari, S. (2010a). Acta Cryst. E66, o2925.  [CrossRef] [details]
Loh, W.-S., Fun, H.-K., Ragavan, R. V., Vijayakumar, V. & Venkatesh, M. (2010b). Acta Cryst. E66, o2563-o2564.  [CrossRef] [details]
Loh, W.-S., Fun, H.-K., Ragavan, R. V., Vijayakumar, V. & Venkatesh, M. (2010c). Acta Cryst. E66, o3050-o3051.  [CrossRef] [details]
Ragavan, R. V., Vijayakumar, V. & Sucheta Kumari, N. (2009). Eur. J. Med. Chem. 44, 3852-3857.  [PubMed] [ChemPort]
Ragavan, R. V., Vijayakumar, V. & Sucheta Kumari, N. (2010). Eur. J. Med. Chem. 45, 1173-1180.  [ISI] [CrossRef] [ChemPort] [PubMed]
Shahani, T., Fun, H.-K., Ragavan, R. V., Vijayakumar, V. & Sarveswari, S. (2010). Acta Cryst. E66, o1697-o1698.  [CrossRef] [details]
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]
Spek, A. L. (2009). Acta Cryst. D65, 148-155.  [ISI] [CrossRef] [details]

Acta Cryst (2011). E67, o151-o152   [ doi:10.1107/S160053681005213X ]

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