1: aq. Na2SO3, aq. NaOH / 15 - 20 °C 2: aq. NaOH / methanol / 30 h / Heating 3: 88 percent / 4 h / 160 °C 4: 92 percent / H2 / 10percent Pd/C / methanol / 3 h / 45 °C / 760 Torr 5: 93 percent / HCl / 20 h / Heating View Scheme

1: aq. Na2SO3, aq. NaOH / 15 - 20 °C 2: aq. NaOH / methanol / 30 h / Heating 3: 88 percent / 4 h / 160 °C 4: 92 percent / H2 / 10percent Pd/C / methanol / 3 h / 45 °C / 760 Torr 5: 93 percent / HCl / 20 h / Heating 6: 87 percent / 4-chloropyridine hydrochloride / dioxane / 2.5 h / Heating View Scheme