Cyclization reactions of alpha, beta unsaturated nitriles with quinoline and cinnoline derivatives: new approaches for synthesis of 4H-pyrano [3, 2-c] quinoline and 4H-pyrano [3, 2-c] cinnoline derivatives

Several new 4H-pyrano [3,2-c] quinolines 7a-d, f-h, 13 a-c, 17 a-c and 4H- pyrano [3,2-c] cinnolines 14a,b were prepared via reacting cinnamonitriles la-h with 4- hydroxyquinolines 2a-d, 3a-c, 5 and 4-hydroxycinnoline 4, respectively. Reaction of 3 a,b or 2 b,c with methylenemalononitrile afforded 4H- pyrano [3,2-c] quinolines 20 a,b