title: Synthetic study on novel immunosuppressant KF20444.
abstract: The two new synthetic routes to 6,7-dihydro-10-fluoro-3-(2-fluorophenyl)-5H- benzo[6,7]cyclohepta[1,2-b]-quinoline-8-carboxylic acid (1), a novel immunosuppressant KF20444, are described. The seven-membered ring construction from 2-[4-(2-fluorophenyl)phenyl]-3-(2-carboxyethyl)-4-chloromethyl-6-fluoroquinoline (17c) was achieved by intramolecular Friedel-Crafts reaction under acidic conditions as the key step. Subsequently, the oxidation of 4-chloromethyl group followed by reduction of carbonyl group on the seven-membered ring afforded 1. This route provides a new method for the synthesis of 1.
authors.affiliation: Sakai Research Laboratories, Kyowa Hakko Kogyo Co., Ltd., 1-1-53, Takasu-cho, Sakai, Osaka 590-8554, Japan. iwao.chujo@kyowa.co.jp
authors.forename: I
authors.initials: I
authors.lastname: Chujo
authors.forename: Y
authors.initials: Y
authors.lastname: Masuda
authors.forename: K
authors.initials: K
authors.lastname: Fujino
authors.forename: S
authors.initials: S
authors.lastname: Kato
authors.forename: T
authors.initials: T
authors.lastname: Ogasa
authors.forename: S
authors.initials: S
authors.lastname: Mohri
authors.forename: M
authors.initials: M
authors.lastname: Kasai
mesh_terms: D001671:Biochemistry / Q000379:methods*; D001713:Biphenyl Compounds / Q000138:chemical synthesis*; D007166:Immunosuppressive Agents / Q000138:chemical synthesis*
chemical_list: D001713:Biphenyl Compounds; D007166:Immunosuppressive Agents; C118187:KF 20444