in diethylene glycol dimethyl ether Heating;

1: 74 percent / dimethylformamide / 2 h / 120 °C 2: 88 percent / potassium carbonate / dimethylformamide / 1 h / 60 °C 3: 85 percent / hydrochloric acid / 1 h / 60 °C 4: 78 percent / pyridine / acetonitrile / 16 h / Ambient temperature 5: 54 percent / 4-(dimethylamino)pyridine / acetonitrile / 16 h / Ambient temperature View Scheme

1: 74 percent / dimethylformamide / 2 h / 120 °C 2: 88 percent / potassium carbonate / dimethylformamide / 1 h / 60 °C 3: 85 percent / hydrochloric acid / 1 h / 60 °C 4: 78 percent / pyridine / acetonitrile / 16 h / Ambient temperature 5: 51 percent / 4-(dimethylamino)pyridine / acetonitrile / 16 h / Ambient temperature View Scheme

in N,N-dimethyl-formamide T=120°C; 3 h;

in N,N-dimethyl-formamide 5 h; Heating;

in N,N-dimethyl-formamide 5 h; Heating;