1: 84 percent / Cs2CO3 / tetrahydrofuran; dimethylformamide / 5 h / 80 °C 2: 80 percent / LiClO4 / diethyl ether / 36 h / 100 °C 3: 79 percent / bis(tributyltin) / benzene / 24 h / 80 °C / Irradiation 4: KOH / methanol / 2 h / Heating 5: copper bronze / quinoline / 2.5 h / 220 - 225 °C View Scheme