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Volume 69 
Part 11 
Page o1677  
November 2013  

Received 15 September 2013
Accepted 15 October 2013
Online 19 October 2013

Key indicators
Powder X-ray study
T = 293 K
Mean [sigma](C-C) = 0.003 Å
R = 0.019
wR = 0.026
Data-to-parameter ratio = 49.6
Details
Open access

Pimobendan B from powder diffraction data

aUniversity of Latvia, Department of Chemistry, Kr. Valdemara Street 48, Riga, LV-1013, Latvia, and bLatvian Institute of Organic Synthesis, Aizkraukles Street 21, Riga, LV-1006, Latvia
Correspondence e-mail: alvis.zvirgzdins@lais.lv

The title mol­ecule, C19H18N4O2 {systematic name: (RS)-6-[2-(4-meth­oxy­phen­yl)-1H-benzimidazol-5-yl]-5-methyl-4,5-di­hydro­pyridazin-3(2H)-one}, adopts an extended conformation. The dihedral angles between the central benzimidazole ring sytem and the pendant meth­oxy­phenyl and pyridazinone residues are 1.41 (18) and 9.7 (3)°, respectively. In the crystal, N-H...N hydrogen bonds link the imadazole groups into [001] chains, and pairs of N-H...O hydrogen bonds link the pyridazinone groups into dimers. Together, these generate a two-dimensional supra­molecular structure parallel to (010). The layers are linked by C-H...[pi] inter­actions.

Related literature

For general information about pimobendan, see: Gordon et al. (2006[Gordon, S. G., Miller, M. V. & Saunders, A. B. (2006). J. Am. Anim. Hosp. Assoc. 42, 90-93.]). For related crystalline forms, see: Boeren et al. (2011[Boeren, M. M. M., Paridaans, R. J., Petkune, S., Lusis, V. & Muceniece, Dz. (2011). US Patent No. 20,110,152,283 A1 20110623.]). Semi-empirical calculations were carried out with HYPERCHEM Professional (Hypercube, 2010[Hypercube (2010). HYPERCHEM Professional. Hypercube, Inc., Gainesville, Florida, USA.]). Refinement of lattice parameters and peak profile determination were performed by Le Bail profile fitting (Le Bail et al., 1988[Le Bail, A., Duroy, H. & Fourquet, J. L. (1988). Mater. Res. Bull. 23, 447-452.])

[Scheme 1]

Experimental

Crystal data
  • C19H18N4O2

  • Mr = 334.37

  • Monoclinic, P 21 /c

  • a = 18.891 (5) Å

  • b = 9.9619 (5) Å

  • c = 9.5029 (8) Å

  • [beta] = 90.799 (13)°

  • V = 1788.2 (5) Å3

  • Z = 4

  • Cu K[alpha] radiation

  • [lambda] = 1.54184 Å

  • [mu] = 0.68 mm-1

  • T = 293 K

  • cylinder, 16 × 0.5 mm

Data collection
  • Bruker D8 diffractometer

  • Specimen mounting: capillary

  • Data collection mode: transmission

  • Scan method: step

  • 2[theta]min = 3.5°, 2[theta]max = 70.00°, 2[theta]step = 0.01°

Refinement
  • Rp = 0.019

  • Rwp = 0.026

  • Rexp = 0.020

  • RBragg = 0.015

  • [chi]2 = 1.690

  • 6651 data points

  • 134 parameters

  • 56 restraints

  • H-atom parameters not refined

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the C12/C20/C15/C24/C22/C21 ring.

D-H...A D-H H...A D...A D-H...A
N3-H42...O9i 0.97 1.85 2.817 (3) 174
N11-H43...N1ii 0.95 2.27 3.2039 (19) 168
C18-H26...Cg1iii 0.97 2.43 3.369 (2) 161
Symmetry codes: (i) -x+1, -y+1, -z; (ii) [x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]; (iii) [-x, y-{\script{1\over 2}}, -z-{\script{1\over 2}}].

Data collection: Dicvol (Boultif & Louër, 2004[Boultif, A. & Louër, D. (2004). J. Appl. Cryst. 37, 724-731.]); cell refinement: FOX (Favre-Nicolin & Cerný, 2002[Favre-Nicolin, V. & Cerný, R. (2002). J. Appl. Cryst. 35, 734-743.]); data reduction: FOX; program(s) used to solve structure: FOX; program(s) used to refine structure: FULLPROF (Rodriguez-Carvajal, 1993[Rodriguez-Carvajal, J. (1993). Physica B, 192, 55-69.]), CRYSTALS (Betteridge et al., 2003[Betteridge, P. W., Carruthers, J. R., Cooper, R. I., Prout, K. & Watkin, D. J. (2003). J. Appl. Cryst. 36, 1487.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); molecular graphics: Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]); software used to prepare material for publication: WinPlotr (Roisnel & Rodriguez-Carvajal, 2000[Roisnel, T. & Rodriguez-Carvajal, J. (2000). EPDIC, 7, 118-123.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB7139 ).


Acknowledgements

This work was supported by the European Regional Development Fund (No. 2011/0014/2DP/2.1.1.1.0/10/APIA/ VIAA/092).

References

Betteridge, P. W., Carruthers, J. R., Cooper, R. I., Prout, K. & Watkin, D. J. (2003). J. Appl. Cryst. 36, 1487.  [Web of Science] [CrossRef] [IUCr Journals]
Boeren, M. M. M., Paridaans, R. J., Petkune, S., Lusis, V. & Muceniece, Dz. (2011). US Patent No. 20,110,152,283 A1 20110623.
Boultif, A. & Louër, D. (2004). J. Appl. Cryst. 37, 724-731.  [Web of Science] [CrossRef] [ChemPort] [IUCr Journals]
Favre-Nicolin, V. & Cerný, R. (2002). J. Appl. Cryst. 35, 734-743.  [Web of Science] [CrossRef] [ChemPort] [IUCr Journals]
Gordon, S. G., Miller, M. V. & Saunders, A. B. (2006). J. Am. Anim. Hosp. Assoc. 42, 90-93.  [PubMed]
Hypercube (2010). HYPERCHEM Professional. Hypercube, Inc., Gainesville, Florida, USA.
Le Bail, A., Duroy, H. & Fourquet, J. L. (1988). Mater. Res. Bull. 23, 447-452.  [CrossRef] [ChemPort] [Web of Science]
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.  [Web of Science] [CrossRef] [ChemPort] [IUCr Journals]
Rodriguez-Carvajal, J. (1993). Physica B, 192, 55-69.  [CrossRef] [ChemPort]
Roisnel, T. & Rodriguez-Carvajal, J. (2000). EPDIC, 7, 118-123.
Spek, A. L. (2009). Acta Cryst. D65, 148-155.  [Web of Science] [CrossRef] [ChemPort] [IUCr Journals]
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.  [Web of Science] [CrossRef] [ChemPort] [IUCr Journals]


Acta Cryst (2013). E69, o1677  [ doi:10.1107/S1600536813028353 ]

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