Carbon Dioxide → 2,6-Dichloro-4-methoxynicotinic Acid

Beteiligte Stoffe

Reaktionsschritte

To a solution of diisopropylamine (1.83 mL) in tetrahydrofuran (40 mL) was added n-butyllithium (2.64 mol/L n-hexane solution, 4.52 mL) at −78° C., and the mixture was stirred at the same temperature for 5 minutes. To the reaction mixture was added a solution of 2,6-dichloro-4-methoxypyridine (1.93 g) in tetrahydrofuran (10 mL) in a dropwise manner, and the mixture was stirred at the same temperature for 30 minutes. To the reaction mixture was added dry ice (5 g), and the mixture was stirred at the same temperature for 30 minutes. To the reaction mixture were added a saturated aqueous ammonium chloride solution and 2 mol/L hydrochloric acid, and the resulting mixture was extracted with ethyl acetate. The extract was washed with brine, and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure, and the residue was purified by column chromatography on silica gel (eluent: ethyl acetate) to give the title compound (1.2 g).

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