Received 24 January 2013
aKrka d.d., Smarjeska cesta 6, 8501 Novo mesto, Slovenia,bUniversity of Ljubljana, Faculty of Pharmacy, Askerceva 7, 1000 Ljubljana, Slovenia, and cUniversity of Ljubljana, Faculty of Chemistry and Chemical Technology, Askerceva 5, 1000 Ljubljana, Slovenia
Correspondence e-mail: firstname.lastname@example.org
Co-crystallizaton of the antifungal drug fluconazole [2-(2,4-difluorophenyl)-1,3-bis(1H-1,2,4-triazol-1-yl)propan-2-ol] with malonic acid in acetonitrile solution resulted in the formation of the title 1:1 co-crystal, C13H12F2N6O·C3H4O4. The geometry around the central fluconazole atom is distorted tetrahedral. The dihedral angles between the triazole rings and the fluorinated phenyl ring are 30.64 (7) and 61.91 (5)°. In the crystal, the basic packing motif may be envisioned as a cyclic aggregate formed of two fluconazole molecules linked by two malonic acid molecules through O-HN and O-HO hydrogen bonds. Such aggregates are further connected into (001) layers by further O-HN hydrogen bonds. The structure also features weak non-classical C-HO and C-HN interactions.
For general aspects of pharmaceutical co-crystals, see, for example: Brittain et al. (2012a,b). For known fluconazole co-crystals, see: Kastelic et al. (2010, 2011). For regulatory classification of pharmaceutical co-crystals, see: US Food and Drug Administration (2011).
Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: GK2552 ).
The financial support of the Slovenian Ministry of Education, Science, Culture and Sport through grant P1-175-103 is gratefully acknowledged. JK thanks ARRS for funding through the Innovative Scheme supported financially by the European Social Fund.
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