Original scientific paper

Crystal Structures of Four Solvates of Lorazepam*: with EthanoI (A), Acetone (B), Dioxane (C), and Cyclohexanone (D)

Boris Kamenar ; Laboratory of General and Inorganic Chemistry, Faculty of Science, University of Zagreb, P. O. Box 153, 41001 Zagreb, Croatia, Yugoslavia
Draginja Mrvoš-Sermek ; Laboratory of General and Inorganic Chemistry, Faculty of Science, University of Zagreb, P. O. Box 153, 41001 Zagreb, Croatia, Yugoslavia
Ante Nagl ; Institute of Textile and Clothing, Faculty of Technology, University of Zagreb, 41000 Zagreb, Croatia, Yugoslavia

Abstract

X-ray structure analysis of four solvates of lorazepam with
ethanol (A), acetone (B), dioxane (C) and cyclohexanone (D) is
d~cribed. All four crystallize in the triclinic system, space group
Pl, and with the lorazepam molecules of essentially the same
conformation. As common in other benzodiazepines, the sevenmembered rings adopt a boat conformation. The four solvates
have different kinds of hydrogen bonding. While in (A), (B) and
(D) lorazepam molecules are interconnected either by N-H ... O
(282 to 292 pm) or O-H .. ,O hydrogen bonds (289 pm) in (C)
such bonding does not exist. The solvent molecules filI cavities
in the crystal structures and are linked to the lorazepam molecules
either by van der Waals interactions as in (A), (B) and (C)
or by hydrogen bond of the O-H.,. O type of 281 pm in (D).
The investigated structures are compared with other lorazepam
derivatives and solvates previously described in the literature.

Keywords

Hrčak ID:

175810

URI

https://hrcak.srce.hr/175810

Publication date:

10.10.1989.

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