Abstract
The synthesis of the new heterocycles, 4-amino-[1] benzofuro [2, 3-g] cinnolines, was accomplished by the intramolecular cyclization of the (Z) configuration of arylhydrazono-acetonitriles (5). The latter compounds were obtained via interaction between diazonium salt of 2-aminodibenzofuran (1) and various active methylene compounds following the Japp-KLINGEMANN reaction. The alkaline treatment of azo intermediates (4), which may be isolated in the course of condensation, gave the corresponding arylhydrazonoacetonitriles (5). A study of the configuration and possible isomerisation of 5 is reported. The linear structure of 4-amino-[1] benzofuro [2, 3-g] cinnolines was elucidated by H-nuclear magnetic resonance.
