1: 89 percent / 4-(dimethylamino)pyridine / 1,2-dichloro-ethane / 1 h / Heating 2: 70 percent / n-Bu3SnH, AIBN / benzene / Heating View Scheme

1: 4-(N,N-dimethlyamino)pyridine; triethylamine / dichloromethane / 0 - 20 °C / Inert atmosphere 2: KF*2H2O; Pd(quinox)Cl2 / isopropyl alcohol / 20 °C / Inert atmosphere View Scheme

1: 4-(N,N-dimethlyamino)pyridine; triethylamine / dichloromethane / 0 - 20 °C / Inert atmosphere 2: KF*2H2O; Pd(quinox)Cl2 / isopropyl alcohol / 20 °C / Inert atmosphere View Scheme

molecular sieve; pyridinium chlorochromate in dichloromethane T=20°C; 8 h;

1: 4-(N,N-dimethlyamino)pyridine; triethylamine / dichloromethane / 0 - 20 °C / Inert atmosphere 2: dichloro bis(acetonitrile) palladium(II); beta-naphthyl methyl ether; caesium carbonate; tri-p-tolyl phosphite / toluene / 24 h / 80 °C View Scheme

formic acid; chlorosulphonyl isocyanate in N,N-dimethyl acetamide T=0 - 20°C;

1: 1) NaH / 1) benzene, 30 min, 2) rt, 20 h 2: 81 percent / KOH / aq. ethanol / Ambient temperature 3: oxalyl chloride, DMF / benzene / 2 h 4: 1) sodium pyridine-2-thiolate N-oxide, DMAP, 2) 2-methylpropane-2-thiol / 1) benzene, reflux, 30 min, 2) irradiation, reflux, 1 h View Scheme

1: benzene / Ambient temperature 2: 79 percent / pyridine / benzene / 1 h 3: 80 percent Chromat. / n-Bu3SnH, AIBN / benzene / Heating View Scheme