title: An efficient access to the synthesis of novel 12-phenylbenzo[6,7]oxepino[3,4-b]quinolin-13(6H)-one derivatives.
abstract: An efficient access to the tetracyclic-fused quinoline systems, 12-phenylbenzo[6,7]oxepino[3,4-b]quinolin-13(6H)-one derivatives 4a-l, is described, involving the intramolecular Friedel-Crafts acylation reaction of 2-(phenoxymethyl)-4-phenylquinoline-3-carboxylic acid derivatives 3a-l aided by the treatment with PPA (polyphosphoric acid) or Eaton's reagent. The required starting compound (2) was obtained by Friedländer reaction of 2-aminobenzophenone (1) with 4-chloroethylacetoacetate by using CAN (cerium ammonium nitrate, 10 mol %) as catalyst at room temperature. The substrates 3a-l were prepared through one-pot reaction of ethyl 2-(chloromethyl)-4-phenylquinoline-3-carboxylate (2) and substituted phenols. Our developed strategy, involving a three-step route, offers easy access to tetracyclic-fused quinoline systems in short reaction times, and the products are obtained in moderate to good yields.
authors.affiliation: Institute of Superfine Chemicals, Bohai University, Jinzhou 121000, China.
authors.forename: Wentao
authors.initials: W
authors.lastname: Gao
authors.forename: Guihai
authors.initials: G
authors.lastname: Lin
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.forename: Xiyue
authors.initials: X
authors.lastname: Tao
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.forename: Lianjie
authors.initials: L
authors.lastname: Sun