1: 2-(4-bromophenyl) thiophene With magnesium in tetrahydrofuran 6 h; Heating; 2: boric acid trimethyl ester in tetrahydrofuran T=-78 - 20°C; 3: With hydrogenchloride in tetrahydrofuran T=20°C; 1 h; Further stages.;

1.1: tetrakis(triphenylphosphine)palladium(0) / 1,2-dimethoxy-ethane / 0.17 h / 20 °C 1.2: 68 percent / aq. Na2CO3 / 12 h / Heating 2.1: Mg / tetrahydrofuran / 6 h / Heating 2.2: tetrahydrofuran / -78 - 20 °C 2.3: 48 percent / aq. HCl / tetrahydrofuran / 1 h / 20 °C View Scheme