2-Methyl-4-(4-methylpiperazin-1-yl)-10H-thieno[2,3-b][1,5]benzodiazepine (olanzapine) propan-2-ol disolvate

In the title solvate, C17H20N4S·2C3H8O, pairs of olanzapine molecules related by a centre of inversion stack along the a axis, forming columns, which are packed parallel to each other along the b axis, forming a sheet arrangement. The columns within these sheets are hydrogen bonded to each other through the propan-2-ol solvent molecules. The diazepine ring of the olanzapine exists in a puckered conformation with the thiophene and phenyl rings making a dihedral angle of 57.66 (7)° and the piperazine ring adopts a chair conformation with the methyl group in an equatorial position.

In the title solvate, C 17 H 20 N 4 SÁ2C 3 H 8 O, pairs of olanzapine molecules related by a centre of inversion stack along the a axis, forming columns, which are packed parallel to each other along the b axis, forming a sheet arrangement. The columns within these sheets are hydrogen bonded to each other through the propan-2-ol solvent molecules. The diazepine ring of the olanzapine exists in a puckered conformation with the thiophene and phenyl rings making a dihedral angle of 57.66 (7) and the piperazine ring adopts a chair conformation with the methyl group in an equatorial position.   Table 1 Hydrogen-bond geometry (Å , ).

Related literature
Symmetry codes: (i) Àx; Ày þ 2; Àz þ 1; (ii) Àx þ 1; Ày þ 1; Àz þ 1.   (Fulton et al., 1997;Tollefson et al., 1997;Sanger et al., 2001). The compound is known to exist in three anhydrous polymorphic forms and 56 solvates including four hydrates have been reported. The crystal structures of two polymorphs and 33 solvates have been reported and all are based on a centrosymmetric dimer motif, which is considered to be the structural building block (Reutzel-Edens et al., 2003;Bhardwaj et al., 2013). The sample of OZPN propan-2-ol solvate was isolated during an experimental physical form screen. The sample was identified as a novel form using multi-sample foil transmission X-ray powder diffraction analysis (Florence et al., 2003).
A suitable sample for single-crystal X-ray diffraction analysis was obtained from slow evaporation of saturated propan-2-ol solution at room temperature. The title compound crystallizes in space group P-1 with one molecule of OZPN and two molecules of propan-2-ol in the asymmetric unit ( Fig. 1). OZPN molecules form centrosymmetric dimers, which stack along the a-direction to form columns. These columns further stack along the b-direction to form sheets and are H-bonded to each other through propan-2-ol molecules, which are present between the sheets. The solvent separated sheets stack along the c-direction to form three-dimensional structure (Fig. 2). XPac (Gelbrich et al., 2005) analysis revealed that this solvate shares 2-D similarity with form I (CSD refcode: UNOGIN01) and dihydrate D (CSD refcode: AQOMAU). The major difference between the structures arises from the relative orientation of the sheets due to incorporation of solvent molecules between them.

Experimental
A single plate shaped crystal was grown from the saturated solution of OZPN in propan-2-ol by isothermal solvent evaporation at 298 K.

Refinement
The positions of the nitrogen and oxygen-bound H atoms were refined freely. All other H atoms were placed in calculated positions and refined in riding modes with C-H = 0.95, 0.98 and 0.99 Å for the aromatic CH, CH 3 and CH 2 groups respectively. The U iso (H) values were set to 1.2 and 1.5 times U eq of their parent C atoms for the aromatic CH, CH 2 and CH 3 groups respectively.

Figure 2
The crystal packing in olanzapine propan-2-ol solvate, viewed down the a-axis. H-bonds are shown by black dotted line.
Carbon, nitrogen, oxygen, sulfur and hydrogen atoms are shown in blue, violet, red, yellow and green colour respectively.
Other hydrogen atoms are omitted for clarity.  Special details Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 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 (Å 2 )
x y z U iso */U eq  (2)