1: oxalyl chloride / CH2Cl2 / 1 h / Heating 2: NaHCO3 / diethyl ether / 2 h / Ambient temperature 3: phosphoryl chloride / benzene / 2 h / Heating 4: 100 percent / 1,2-dichloro-benzene / 1 h / 180 °C 5: 62 percent / NaBH4 / methanol / Ambient temperature View Scheme

oxalyl dichloride in dichloromethane 1 h; Heating;