Synthesis of the Fused Heterobicycles 5-Pyridin-2-yl-thieno[3,2-b]pyridine, 6-Pyridin-2-yl-thieno[2,3-b]pyridine and 6-Pyridin-2-yl-thieno[3,2-c]pyridine - Nurkkala, Lasse J; Steen, Robert O; Dunne, Simon J (Synthesis, 2006)