Nitration of dithieno[3,2‐ b :3′,2′‐ d ]pyridine and dithieno[3,2‐ b :3′,4′‐ d ]pyridine

Nitration of dithieno[3,2‐ b :3′,2′‐ d ]pyridine ( 4 ) and dithieno[3,2‐ b :3′,4′‐ d ]pyridine ( 5 ) has been studied. Nitration of 4 occurred in both positions of the C ring, while 5 was predominantly substituted on the 3,4‐fused ring. The structures of the nitro derivatives were proven by extensive use of 1 H and 13 C nmr spectroscopy.