Photochemical synthesis of [2.2](3,8)-pyridazinophane and quinolinophane-2(1H)-one as well as synthesis of [2](5,8)-quinolinophanes and fused spiro-pyranoindanoparacyclophanes

Syntheses of various classes of unreported heterophanes derived from [2.2]paracyclophane are herein reported. The key to their successful synthesis depends on the photochemical synthesis of pyridazinophane and quinolinophane-2(1H)-one from freshly prepared 4-([2.2]paracyclophanyl)-azo-4'-[2.2]paracyclophane and 4-([2.2]paracyclophanyl)cinnnamanilide, respectively. Reactions of 4-amino[2.21paracyclophane with either acetyl- or benzoylacetone afforded condensed products. Then ring closure using polyphosphoric acid (PPA) at 120degreesC gave, in near quantitative yields, quinolinophanes. Reactions of [2](4,7)-indano-[2]paracyclophane-1-ylidene-propanedinitrile with active methylene compounds afforded fused spiro-pyranoindanoparacyclophane derivatives. (C) 2003 Elsevier Science Ltd. All rights reserved.