1: thionyl chloride / dimethylformamide / 4 h / 40 - 45 °C 2: 79 percent / pyridine / diethyl ether / 30 h / Heating 3: 1.) sodium hydride, 2.) 1,2-bis(diphenylphosphino)ethane / 2.) tetrakis(triphenylphosphine)palladium(0) / 1,) THF, 0 deg C, 30 min; room temperature, 15 min, 2.) reflux 4: 86 percent / tetramethylammonium acetate / hexamethylphosphoric acid triamide / 3 h / 95 - 100 °C 5: 94 percent / disodium hydrogen phosphate, 6percent sodium amalgam / ethanol; tetrahydrofuran / 0.75 h / -20 °C View Scheme