Acta Cryst. (2003). E59, o41-o43  [ doi:10.1107/S1600536802022481 ]

Cilansetron hydrochloride monohydrate, modification B (orthorhombic)

P. G. Jones, H. Möller and E. Finner

Abstract: The absolute configuration of the orthorhombic form of the title compound, (-)-5,6,9,10-tetrahydro-10-[(2-methyl-1H-imidazol-1-yl)methyl]-4H-pyrido[3,2,1-jk]carbazol-11(8H)-one monohydrochloride monohydrate, C₂₀H₂₂N₃O⁺·Cl^-·H₂O, was established as R at the asymmetric carbon adjacent to the carbonyl function. This form [cf. the monoclinic form; Jones et al. (2003). Acta Cryst. E59, o38-o40] also involves two independent formula units with different ring conformations of the six-membered N-heterocycle, and somewhat different orientations of the imidazole ring. Classical hydrogen bonding leads to a helical chain of alternating water and chloride residues, with cations hydrogen bonded laterally to the water molecules.

Online 19 December 2002

Copyright © International Union of Crystallography
IUCr Webmaster