Crystal structures of mefloquine-oxazolidine derivatives, 4-[3-(halophenyl)hexahydro[1,3]oxazolo[3,4-a]pyridin-1-yl]- 2,8-bis(trifluoromethyl)quinolines.

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Abstract

Crystal structures are reported for five racemic 4-{3-(halophenyl)hexahydro[1,3]oxazolo[3,4-a]pyridin-1- yl}-2,8-bis(trifluoromethyl)quinolines, 2, namely (2: X = 2-F, 3-Br, 4-Cl, 4-Br and 4-F), prepared from mefloquine and XC₆H₅CHO. In each case, the compound crystallizes in the triclinic space group, P1̄, with Z = 2. All molecules have ‘‘F’’ shapes with the X-phenyl and quinoline rings lying on one side of the best plane through the fused oxazolidine- piperidine rings. Differences in the conformations of the molecules are indicated by the differences in the interplanar angles. In each case, the supramolecular arrangements are made up from combinations of π … π and some of C-H…X and C-X… π (X = halo) interactions. Two similar structural sub-sets found in the crystal structures of the five derivatives are centrosymmetric π … π-linked dimers and centrosymmetric cage-like dimers. The cage-like dimers, formed by the intermeshing of the rings of the monomers, are generated from different weak intermolecular interactions, which include C-H…X and C-X… π (X = halo) interactions. Comparisons are made between the activities of the mefloquine- oxazolidine derivatives in in-vitro tests against the multidrug-resistant tuberculosis strain and conformations, as measured by interplanar angles.

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Keywords: X-ray crystallography; Quinoline derivatives; Mefloquine derivatives; π … π interactions: C-H…X (X = halo) interactions; C-X … π (X = halo) interactions Document Type: Research Article DOI: http://dx.doi.org/10.1524/zkri.2013.1691 Publication date: 1 de dezembro de 2013