1: benzene / 14 h / Heating 2: 57 percent / powdered zinc / acetic acid; H2O / 4 h / Ambient temperature 3: oxalyl chloride / 0.08 h / 40 °C 4: pyridine / tetrahydrofuran / 0.33 h / -30 - 0 °C 5: 1.) powdered zinc, 2.) powdered zinc, conc. HCl / 1.) -30 deg C to room temp, 1.5 h; room temp., 1.5 h, 2.) acetic acid, room temp., 3 h View Scheme