copper; potassium carbonate in N,N-dimethyl-formamide 7 h; Heating;

Multi-step reaction with 5 steps 1: 79 percent / K2CO3 / dimethylformamide / 3 h / 100 °C2: 95 percent / NaBH4 / ethanol; H2O / 3 h / Heating3: CaCl2, HCl / benzene / 2 h / overnight4: dimethylformamide / 4 h / Heating5: 13 percent / acetic anhydride, HBr / acetic acid / 3.5 h / 60 - 70 °C  

Multi-step reaction with 4 steps 1: 95 percent / NaBH4 / ethanol; H2O / 3 h / Heating2: CaCl2, HCl / benzene / 2 h / overnight3: dimethylformamide / 4 h / Heating4: 13 percent / acetic anhydride, HBr / acetic acid / 3.5 h / 60 - 70 °C  

Multi-step reaction with 3 steps 1: CaCl2, HCl / benzene / 2 h / overnight2: dimethylformamide / 4 h / Heating3: 13 percent / acetic anhydride, HBr / acetic acid / 3.5 h / 60 - 70 °C