1: With trichlorophosphate T=80°C; 2: With sodium hydroxide T=50°C;

1.1: 4-chloropyridinium chloride / dioxane / Heating 2.1: Heating 3.1: POCl3 / 80 °C 3.2: 10 percent NaOH / 50 °C View Scheme

1.1: NaH / tetrahydrofuran / Heating 2.1: dimethylformamide / 20 °C 3.1: NaH / methanol / Heating 4.1: 4-chloropyridinium chloride / dioxane / Heating 5.1: Heating 6.1: POCl3 / 80 °C 6.2: 10 percent NaOH / 50 °C View Scheme

1.1: acetonitrile / 20 °C 2.1: NaH / tetrahydrofuran / Heating 3.1: dimethylformamide / 20 °C 4.1: NaH / methanol / Heating 5.1: 4-chloropyridinium chloride / dioxane / Heating 6.1: Heating 7.1: POCl3 / 80 °C 7.2: 10 percent NaOH / 50 °C View Scheme

1.1: SOCl2 / dioxane / 20 °C 2.1: acetonitrile / 20 °C 3.1: NaH / tetrahydrofuran / Heating 4.1: dimethylformamide / 20 °C 5.1: NaH / methanol / Heating 6.1: 4-chloropyridinium chloride / dioxane / Heating 7.1: Heating 8.1: POCl3 / 80 °C 8.2: 10 percent NaOH / 50 °C View Scheme