acetic acid in methanol T=0 - 25°C; Yield given;

1: 81 percent / pyridine / CH2Cl2 / 3 h / 0 - 20 °C 2: 75 percent / 1,2-bis(diphenylphosphino)ethane / tetrakis(triphenylphosphine)palladium(0) / tetrahydrofuran / 24 h / 20 °C 3: 41 percent / aq. HCl / diethyl ether / 1 h 4: 0.96 g / DMAP; Et3N / CH2Cl2 / 20 °C 5: 74 percent / iodine / acetonitrile / 16 h / 0 - 20 °C 6: 70 percent / DBU / dimethylformamide / 1 h / 90 °C View Scheme

1: 75 percent / 1,2-bis(diphenylphosphino)ethane / tetrakis(triphenylphosphine)palladium(0) / tetrahydrofuran / 24 h / 20 °C 2: 41 percent / aq. HCl / diethyl ether / 1 h 3: 0.96 g / DMAP; Et3N / CH2Cl2 / 20 °C 4: 74 percent / iodine / acetonitrile / 16 h / 0 - 20 °C 5: 70 percent / DBU / dimethylformamide / 1 h / 90 °C View Scheme

1: 74 percent / iodine / acetonitrile / 16 h / 0 - 20 °C 2: 70 percent / DBU / dimethylformamide / 1 h / 90 °C View Scheme

1: 0.96 g / DMAP; Et3N / CH2Cl2 / 20 °C 2: 74 percent / iodine / acetonitrile / 16 h / 0 - 20 °C 3: 70 percent / DBU / dimethylformamide / 1 h / 90 °C View Scheme

1: 41 percent / aq. HCl / diethyl ether / 1 h 2: 0.96 g / DMAP; Et3N / CH2Cl2 / 20 °C 3: 74 percent / iodine / acetonitrile / 16 h / 0 - 20 °C 4: 70 percent / DBU / dimethylformamide / 1 h / 90 °C View Scheme

1: 74 percent / EtONa / ethanol / 18 h / Ambient temperature 2: 6 N aq. HCl / 18 h / Heating 3: H2SO4 conc. / 3 h / Heating 4: 55 percent / parachloranile / xylene / 16 h / Heating View Scheme

1: 6 N aq. HCl / 18 h / Heating 2: H2SO4 conc. / 3 h / Heating 3: 55 percent / parachloranile / xylene / 16 h / Heating View Scheme

1: 34 percent 2: 25 °C 3: AcOH / methanol / 0 - 25 °C View Scheme

1: 25 °C 2: AcOH / methanol / 0 - 25 °C View Scheme