1: ethanol / 0.08 h / 20 °C 2: bromine / tetrachloromethane / 3.08 h / 20 °C 3: tetrakis(triphenylphosphine) palladium(0); caesium carbonate / ethanol; toluene / 4 h / |Reflux 4: trifluoroacetic acid / 1,2-dichloro-ethane / 18 h / |Reflux View Scheme