The synthesis of monomethoxynaphtho[1′,2′:4,5]thieno[2,3‐ c ]quinolines

A series of monomethoxynaphtho[1′,2′:4,5]thieno[2,3‐ c ]quinolines has been prepared by photocyclization of the appropriate N ‐methoxyphenyl‐1‐chloronaphtho[2,1‐ b ]thiophene‐2‐carboxamides. Some of the lactams obtained were converted into the thiolactams and their S ‐methyl derivatives. The lactams were also converted into the corresponding 6‐chloro derivatives. Some of these were catalytically dechlorinated into the monomethoxynaphtho[1′,2′:4,5]thieno[2,3‐ c ]quinolines which were then quaternized into the N ‐methyl quaternary salts.