1: With hydrogenchloride; sodium nitrite in water T=0°C; 0.5 h; 2: With potassium iodide in water T=0 - 20°C; Further stages.;

N-iodo-succinimide; palladium diacetate; toluene-4-sulfonic acid in 1,2-dichloro-ethane T=70°C; 12 h; Sealed tube;