title: Convergent synthesis of 6-substituted phenanthridines via anionic ring closure.
abstract: [reaction: see text] The addition of organometallic derivatives to the cyano group of 2-(2-fluorophenyl)benzonitrile followed by intramolecular nucleophilic substitution produces 6-substituted phenanthridines. Alkyllithiums, aryllithiums, and sterically nondemanding lithium amides reacted at -78 degrees C to produce the 6-substituted phenanthridines in 82-98% yield upon warming to room temperature. The addition of the corresponding Grignard reagents requires an excess of the organometallic reagent and extented reaction times at elevated temperature.
authors.affiliation: The Royal Danish School of Pharmacy, Department of Medicinal Chemistry, Universitetsparken 2, DK-2100, Copenhagen, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Lysén
authors.forename: Jesper L
authors.initials: JL
authors.lastname: Kristensen
authors.forename: Per
authors.initials: P
authors.lastname: Vedsø
authors.forename: Mikael
authors.initials: M
authors.lastname: Begtrup