title: Three 5H-indeno[1,2-c]pyridazin-5-one derivatives, potent type-B monoamine oxidase inhibitors.
abstract: The structures of three compounds, namely 7-methoxy-2-[3-(trifluoromethyl)phenyl]-9H-indeno[1,2-c]pyridazin-9-one, C19H11F3N2O2, (Id), 6-methoxy-2-[3-(trifluoromethyl)phenyl]-9H-indeno[1,2-c]pyridazin-9-one, C19H11F3N2O2, (IId), and 2-methyl-6-(4,4,4-trifluorobutoxy)-9H-indeno[1,2-c]pyridazin-9-one, C16H13F3N2O2, (IIf), which are potent reversible type-B monoamine oxidase (MAO-B) inhibitors, are presented and discussed. Compounds (Id) and (IId) crystallize in a nearly planar conformation. The crystal structures are stabilized by weak C-H...O hydrogen bonds. The packing is dominated by pi-pi stacking interactions between the heterocyclic central moieties of centrosymmetrically related molecules. In compound (IIf), the trifluoroethyl termination is almost perpendicular to the plane of the ring.
authors.affiliation: Laboratory of Molecular and Structural Chemistry, University of Namur, 61 rue de Bruxelles, B-5000 Namur, Belgium. raphael.frederick@fundp.ac.be
authors.forename: Raphaël
authors.initials: R
authors.lastname: Frédérick
authors.forename: Bernadette
authors.initials: B
authors.lastname: Norberg
authors.forename: François
authors.initials: F
authors.lastname: Durant
authors.forename: Frederic
authors.initials: F
authors.lastname: Ooms
authors.forename: Johan
authors.initials: J
authors.lastname: Wouters
mesh_terms: D018360:Crystallography, X-Ray; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D006860:Hydrogen Bonding; D007192:Indenes / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D008996:Monoamine Oxidase Inhibitors / Q000737:chemistry*; D011724:Pyridazines / Q000737:chemistry*
chemical_list: D006575:Heterocyclic Compounds, 3-Ring; D007192:Indenes; D008996:Monoamine Oxidase Inhibitors; D011724:Pyridazines