1: 70 percent / NaHCO3; H2O / Pd(PPh3)4 / 1,2-dimethoxy-ethane / 3 h / Heating 2: 96 percent / NBS / dimethylformamide / 30 h / 0 - 20 °C View Scheme

water; sodium hydrogencarbonate; tetrakis(triphenylphosphine) palladium(0) in ethylene glycol dimethyl ether Dimerization; Cross-coupling; 3 h; Heating;

1: With lithium diisopropyl amide in tetrahydrofuran; n-heptane; ethylbenzene Metallation; 1 h; 2: With boric acid trimethyl ester in tetrahydrofuran; n-heptane; ethylbenzene T=20°C; Substitution; 3: With hydrogenchloride Hydrolysis; Further stages.;

1.1: Ni(dppp)Cl2 / diethyl ether 2.1: n-BuLi; i-Pr2NH / hexane; tetrahydrofuran / 3 h / -78 - 20 °C 2.2: B(OCH3)3 / hexane; tetrahydrofuran / -78 - 20 °C 2.3: HCl / tetrahydrofuran; hexane; H2O View Scheme