1: potassium carbonate / N,N-dimethyl-formamide / 1 h / 25 - 40 °C 2: sodium methylate / N,N-dimethyl-formamide; methanol / 0.5 h / 50 °C 3: palladium diacetate; triphenylphosphine; potassium phosphate / tetrahydrofuran / 5.5 h / 20 °C / |Reflux; |Inert atmosphere 4: sodium hydroxide; water / methanol; tetrahydrofuran / 3 h / |Reflux 5: thionyl chloride / N,N-dimethyl-formamide; tetrahydrofuran / 1 h / 20 - 30 °C 6: triethylamine / N,N-dimethyl-formamide; tetrahydrofuran / 1.5 h / 45 - 55 °C View Scheme