Facile preparation of polycyclic halogen-substituted 1,2,3-triazoles by using intramolecular Huisgen cycloaddition

Abstract

When 1-(ω-azidoalkyl)-2-(2,2-dihalovinyl)arenes were heated in DMF, the intramolecular Huisgen cycloaddition of an azido group with a 1,1-dihalovinyl group afforded 5-halo-1,2,3-triazole-fused tricyclic benzo compounds. Based on the remaining bromo groups, carbon elongation by the Mizoroki–Heck or Suzuki–Miyaura coupling reactions, followed by an intramolecular Friedel–Crafts reaction, afforded polycyclic compounds with fused triazole rings. Thereafter, the bromo groups were converted into 2-nitrophenyl groups via the Suzuki–Miyaura coupling reaction, which was followed by the Cadogan reaction; a fluorescent pentacyclic compound was obtained.