Characterization of quinoline derivatives. I. 6,7-Dihydro-8-(4-methyl-1-piperazinyl)[1]-benzoxepino[4,5-c]quinoline 0.13-hydrate

The title compound, C22H23N3O.0.13H(2)O, is a novel potent and selective serotonin 5-HT3 receptor antagonist. Three independent molecules constitute the asymmetric unit. While two of these molecules show only small differences in their metric and conformational parameters, the third differs from the other two, mainly as a result of the conformation of the oxepine ring. The conformations of the seven-membered ring determine quite different orientations of the oxepine-fused benzene ring, whose role is important in the exploitation of biological activity.