5-Chloro-2-methoxypyridine-4-carboxaldehyde can be used as a pharmaceutical synthesis intermediate and an organic synthesis intermediate, mainly in laboratory research and development processes and chemical and pharmaceutical synthesis processes.
To a solution of 5-chloro-2-methoxy4-methylpyridine (20 mmol) in N,N-dimethylformamide (38 mL) was added tert-butoxybis(dimethylamino)methane (7.0 mL, 33.9 mmol). The reaction mixture was heated at 120C for 2 hours. The cooled reaction mixture was concentrated in vacuo to give a thick orange oil, which was redissolved in tetrahydrofuran (40 mL) and slowly poured at 0 C into a flask containing a slurry of sodium periodate in water (150 mL) separated. The reaction flask was equipped with a top stirrer and allowed to warm up to room temperature. The reaction mixture was vigorously mixed for three hours and later diluted with dichloromethane (150 mL) and filtered. The collected solid was washed with dichloromethane (2x150mL) and the organic layer was separated from the filtrate and washed with saturated sodium bicarbonate solution (50mL). The aqueous layer was neutralized by addition of solid sodium bicarbonate and subsequently back-extracted with dichloromethane (,100 mL). The organic fractions were combined, dried over sodium sulfate, filtered, and evaporated in vacuo to give a residue, and said residue was purified by precipitation chromatography (silica, 120 g, ISCO, 0-40% ethyl acetate in heptane) to give the title compound as a beige solid 5-chloro-2-methoxypyridine-4-carbaldehyde.
