1: 39 percent / methanesulfonic acid / benzene / 36 h / Heating 2: 35 percent / various solvent(s) / 255 °C 3: 98 percent / KOH / aq. ethanol / 2 h / Heating 4: 1.) KOH, Al-foil, 2) HCl, FeCl3 / 1.) 50percent aq. EtOH, 2.) reflux, 30 min 5: 1.) 1,1'-carbonyldiimidazole, 3.) conc. HCl / 1.) DMF, 20 to 40 deg C, 20 min, 2.) 20 deg C, 15 min View Scheme

1: 20 percent / ethanol / 3 h / Heating 2: 93 percent / Cu-powder / 280 - 290 °C 3: 34 percent / SeO2 / a) 180 to 190 deg C, b) 280 to 290 deg C, 2 min 4: 1.) 1,1'-carbonyldiimidazole, 3.) conc. HCl / 1.) DMF, 20 to 40 deg C, 20 min, 2.) 20 deg C, 15 min View Scheme

1: 39 percent / methanesulfonic acid / benzene / 36 h / Heating 2: 35 percent / various solvent(s) / 255 °C 3: 98 percent / KOH / aq. ethanol / 2 h / Heating 4: 1.) KOH, Al-foil, 2) HCl, FeCl3 / 1.) 50percent aq. EtOH, 2.) reflux, 30 min 5: 1.) 1,1'-carbonyldiimidazole, 3.) conc. HCl / 1.) DMF, 20 to 40 deg C, 20 min, 2.) 20 deg C, 15 min View Scheme

1: 20 percent / ethanol / 3 h / Heating 2: 93 percent / Cu-powder / 280 - 290 °C 3: 34 percent / SeO2 / a) 180 to 190 deg C, b) 280 to 290 deg C, 2 min 4: 1.) 1,1'-carbonyldiimidazole, 3.) conc. HCl / 1.) DMF, 20 to 40 deg C, 20 min, 2.) 20 deg C, 15 min View Scheme

1: 93 percent / Cu-powder / 280 - 290 °C 2: 34 percent / SeO2 / a) 180 to 190 deg C, b) 280 to 290 deg C, 2 min 3: 1.) 1,1'-carbonyldiimidazole, 3.) conc. HCl / 1.) DMF, 20 to 40 deg C, 20 min, 2.) 20 deg C, 15 min View Scheme

hydrogenchloride; 1,1'-carbonyldiimidazole 1.) DMF, 20 to 40 deg C, 20 min, 2.) 20 deg C, 15 min; Multistep reaction;