potassium fluoride; anhydrous tetramethylammonium chloride in dimethyl sulfoxide T=150°C; 2 h;

1: With n-butyllithium in tetrahydrofuran; hexane T=-75°C; 2 h; 2: With bromine T=-75°C; 1 h;

1.1: 65 percent / aq. CuSO4 / Heating 2.1: BuLi / tetrahydrofuran; hexane / 2 h / -75 °C 2.2: 78 percent / Br2 / 1 h / -75 °C View Scheme

1.1: 88 percent / hydrazine monohydrate / ethanol / 2 h / Heating 2.1: 65 percent / aq. CuSO4 / Heating 3.1: BuLi / tetrahydrofuran; hexane / 2 h / -75 °C 3.2: 78 percent / Br2 / 1 h / -75 °C View Scheme

1.1: 90 percent / Zn; aq. ammonia / 6 h / 0 °C 2.1: 88 percent / hydrazine monohydrate / ethanol / 2 h / Heating 3.1: 65 percent / aq. CuSO4 / Heating 4.1: BuLi / tetrahydrofuran; hexane / 2 h / -75 °C 4.2: 78 percent / Br2 / 1 h / -75 °C View Scheme