Synthesis of 4-Arylthieno[2,3-b]pyridines and 4-Aminothieno[2,3-b]pyridines via a Regioselective Bromination of Thieno[2,3-b]pyridine

The first regioselective, mild bromination of thieno[2,3-b]pyridine is described herein. The reaction proceeds with selectivity toward the 4-position (87% isolated yield). Subsequent cross-coupling reactions proceed in excellent yields and demonstrate the potential of 4-bromothieno[2,3-b]pyridine as a building block for use in drug discovery research.