Three new olanzapine structures: the acetic acid monosolvate, and the propan-2-ol and propan-2-one hemisolvate monohydrates

The crystal structures of three new solvates of olanzapine [systematic name: 2-methyl-4-(4-methylpiperazin-1-yl)-10H-thieno[2,3-b][1,5]benzodiazepine], namely olanzapine acetic acid monosolvate, C17H20N4S center dot C2H4O2, (I), olanzapine propan-2-ol hemisolvate monohydrate, C17H20N4S center dot 0.5C(3)H(8)O center dot H2O, (II), and olanzapine propan-2-one hemisolvate monohydrate, C17H20N4S center dot 0.5C(3)H(6)O center dot H2O, (III), are presented and compared with other known olanzapine forms. There is a fairly close resemblance of the molecular conformation for all studied analogues. The crystal structures are built up through olanzapine dimers, which are characterized via C-H center dot center dot center dot pi interactions between the aliphatic fragment (1-methylpiperazin-4-yl) and the aromatic fragment (benzene system). All solvent (guest) molecules participate in hydrogen-bonding networks. The crystal packing is sustained via intermolecular N(hos)t-H center dot center dot center dot O-guest, O-guest-H center dot center dot center dot N-host, O-guest-H center dot center dot center dot O-guest and C-host-H center dot center dot center dot O-guest hydrogen bonds. It should be noted that the solvent propan-2-ol in (II) and propan-2-one in (III) show orientational disorder. The propan-2-ol molecule lies close to a twofold axis, while the propan-2-one molecule resides strictly on a twofold axis through the carbonyl C atom. In both cases, the water molecules present positional disorder of the H atoms.