2-chloro-6-methylpyridin-3-ol synthesis

Yield: 67.3%

Reaction Conditions:

with hydrogenchloride;chlorine in water at 68 - 74;

Steps:

E.a
5-Hydroxy-2-methylpyridine (1-014-01) (27.01 g) was dissolved in conc. hydrochloric acid (200 mL) and to the reaction mixture was bubbled chlorine gass at 68 to 74 °C. After the reaction mixture was stood overnight, the volatile was removed by bubbling nitrogen gas. The reaction mixture was evaporated under reduced pressure to give the crystal residue. The crystal residue was dissolved in methanol, and treated with active charcoal. After recrystallization, the desired 2-chloro-3-hyroxy-6-methylpyridine (1-014-02) (23.96 g, 67.3%) was obtained

References:

SHIONOGI & CO., LTD. EP1477186, 2004, A1 Location in patent:Page/Page column 31