Pyridinium N-2´-pyridylaminide: radical cyclization for the synthesis of benzonaphthyridine derivatives

The synthesis of benzonaphthyridine derivatives that incorporate a 2-aminopyridine moiety can be performed by intramolecular radical pyridylation of the appropriate substrates, obtained from pyridinium N-2¿-pyridylaminide, using TTMSS and AIBN.Financial support from the CICYT (project CTQ2005- 08902/BQU) and two grants from the Universidad de Alcala (A.S) and the Ministerio de Educacion y Ciencia (Spain) (A.N.) are gratefully acknowledged