potassium carbonate in dimethyl sulfoxide T=25°C; 4 h;

1: 92 percent / propan-2-ol / 18 h / 25 °C 2: 13 percent / pyridinium hydrochloride / 1 h / 205 °C 3: 42 percent / K2CO3 / dimethylsulfoxide / 4 h / 25 °C View Scheme

1: 92 percent / propan-2-ol / 18 h / 25 °C 2: 13 percent / pyridinium hydrochloride / 1 h / 205 °C 3: 42 percent / K2CO3 / dimethylsulfoxide / 4 h / 25 °C View Scheme

1: 79 percent / 0.25 h / 210 °C 2: 82 percent / 1.) COCl)2, DMF / 1,2-dichloro-ethane / 1.) 25 deg C, 2.) reflux, 4 h 3: 92 percent / propan-2-ol / 18 h / 25 °C 4: 13 percent / pyridinium hydrochloride / 1 h / 205 °C 5: 42 percent / K2CO3 / dimethylsulfoxide / 4 h / 25 °C View Scheme

1: 82 percent / 1.) COCl)2, DMF / 1,2-dichloro-ethane / 1.) 25 deg C, 2.) reflux, 4 h 2: 92 percent / propan-2-ol / 18 h / 25 °C 3: 13 percent / pyridinium hydrochloride / 1 h / 205 °C 4: 42 percent / K2CO3 / dimethylsulfoxide / 4 h / 25 °C View Scheme

in ethanol Heating;