Functionalization of the A ring of pyridoacridine as a route toward greater structural diversity. Synthesis of an octacyclic analogue of eilatin.

In an effort to increase the structural diversity of pyrido[4,3,2-kl]acridines, compounds containing amino substituents on the A ring were synthesized. The key-reactions involve regioselective electrophilic aromatic substitutions. The methodology was applied to the synthesis of the extended angular octacycle 8, which conjugates the physicochemical and spectroscopic properties of the pyridoacridine skeleton with the ability of [1,10]phenanthroline ring for metal complexation. The 9-aminopyridoacridine 4 displays significant cytostatic activities against two cancer cell lines, and may be considered as a new lead in the search of active derivatives.