The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 23 . Naphtho[2′,1′:4,5]thieno-[2,3-c]naphtho[2,1-f]quinoline

A previously unknown heterocyclic ring system, naphtho[2′,1′:4,5]thieno[2,3‐c]naphtho[2,1‐f]quinoline (14), was synthesized via oxidative photocyclization of 3‐chloro‐N‐(2‐phenanthryl)naphtho[1,2‐b]‐thiophene‐2‐carboxamide (9). Further elaboration of the lactam 10 yielded the unsubstituted ring system 14. Structural confirmation of compound 14 was accomplished by a total assignment of its 1H and 13C nmr spectra utilizing the concerted two‐dimensional nmr spectroscopic methods.