Chemistry of thienopyridines. IV. Syntheses of 5‐substituted thieno[2,3‐b] pyridines

Chemical transformations on 5‐acetylthieno[2,3–6] pyridine produced 5‐NH 2 , 5‐CO 2 H, and 5‐CH 2 CO 2 H substituents. The 5‐amino compound underwent facile diazotization (plus Sand‐meyer reaction), Schiff's base formation, and acylation. Treatment of the derived 5‐bromo compound with potassium amide in liquid ammonia gave a mixture of 4‐amino (major) and 5‐amino isomers. Nmr spectral data are reported for the 5‐substituted thieno [2,3‐ b ] pyridine system.