sodium hydride in 1,4-dioxane 1.) r.t., 2 h; 100 deg C, 20 h, 2.) 30-35 deg C, 300 psi, 40 h;

1: 88 percent / Cl2 / 10 - 15 °C 2: 70 percent / F2, NaF / various solvent(s) / -10 °C / Irradiation 3: 54 percent / Zn, Br2 / dimethylformamide / 6 h / 50 °C View Scheme