sodium carbonate; tetrakis(triphenylphosphine) palladium(0) in ethylene glycol dimethyl ether; ethanol rt, 15 min; reflux, 48 h;

1: bromine / acetic acid 2: potassium carbonate / dimethylformamide 3: 96 percent / aq. Na2CO3 / Pd(PPh3)4 / 1,2-dimethoxy-ethane; ethanol / rt, 15 min; reflux, 48 h View Scheme

1: potassium carbonate / dimethylformamide 2: 96 percent / aq. Na2CO3 / Pd(PPh3)4 / 1,2-dimethoxy-ethane; ethanol / rt, 15 min; reflux, 48 h View Scheme

1.1: n-BuLi / tetrahydrofuran / 0.25 h / -78 °C 1.2: trimethyl borate / tetrahydrofuran / -78 - 20 °C 1.3: HCl; water / 0 °C 2.1: 86 percent / Na2CO3; water / Pd(PPh3)4 / 1,2-dimethoxy-ethane / 18 h / Heating View Scheme

copper T=205°C;