The Synthesis of Novel Polycyclic Heterocyclic Ring Systems via Photocyclization. 12. Benzo[h]naphtho‐[2′,1′:4,5]thieno[2,3‐c]quinoline and benzo[f]‐naphtho[2′,1′:4,5]thieno[2,3‐c]quinoline

Abstract The synthesis of two previously unknown heterocyclic ring systems, namely benzo[h]naphtho[2′,1′:4,5]thi‐eno[2,3‐c]quinoline (1) and benzo[f]naphtho[2′,1:4,5]thieno[2,3‐c]quinoline (2) was accomplished via photocyclization of the appropriate amides followed by chlorination and catalytic dechlorination. The total assignment of 1H and 13C nmr spectra of 2 was determined utilizing two‐dimensional nmr methods, providing unequivocal structural proof of the two novel polycyclic ring systems.