copper(l) iodide; potassium iodide in DMF (N,N-dimethyl-formamide) T=130°C; 3 h; Microwave irradiation;

1: 56 percent / pertrifluoroacetic acid / CH2Cl2 / 13 h / Ambient temperature 2: sodium borohydride / methanol / 3 h / Ambient temperature 3: 82 percent / p-Toluenesulfonic acid / benzene / 3 h / Heating 4: sulfurated sodium borohydride / tetrahydrofuran / 16 h / Ambient temperature 5: 1.) NaNO2, 20percent H2SO4, 2.) KI / 1.) H2O, 0 deg C, 12 min, 2.) H2O, flask in aluminum foil, 30 min stirring View Scheme

1: 82 percent / p-Toluenesulfonic acid / benzene / 3 h / Heating 2: sulfurated sodium borohydride / tetrahydrofuran / 16 h / Ambient temperature 3: 1.) NaNO2, 20percent H2SO4, 2.) KI / 1.) H2O, 0 deg C, 12 min, 2.) H2O, flask in aluminum foil, 30 min stirring View Scheme

1: sodium borohydride / methanol / 3 h / Ambient temperature 2: 82 percent / p-Toluenesulfonic acid / benzene / 3 h / Heating 3: sulfurated sodium borohydride / tetrahydrofuran / 16 h / Ambient temperature 4: 1.) NaNO2, 20percent H2SO4, 2.) KI / 1.) H2O, 0 deg C, 12 min, 2.) H2O, flask in aluminum foil, 30 min stirring View Scheme

1: sulfurated sodium borohydride / tetrahydrofuran / 16 h / Ambient temperature 2: 1.) NaNO2, 20percent H2SO4, 2.) KI / 1.) H2O, 0 deg C, 12 min, 2.) H2O, flask in aluminum foil, 30 min stirring View Scheme

1: 1.) NaNO2, 20percent H2SO4, 2.) KI / 1.) H2O, 0 deg C, 12 min, 2.) H2O, flask in aluminum foil, 30 min stirring View Scheme

Yield given. Multistep reaction;