反应详情

To a solution of 2,5-difluoropyridine-3-carboxylic acid (3.00 g), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (4.34 g), 1-hydroxybenzotriazole (127 mg), and N,O-dimethylhydroxylamine hydrochloride (1.93 g) in N,N-dimethylformamide (30 ml), diisopropylethylamine (7.42 ml) was added, and the mixture was stirred overnight at room temperature. Ethyl acetate and water were added to the reaction solution to separate the aqueous and organic layers. The aqueous layer was subjected to extraction with ethyl acetate. The organic layers were combined, washed with saturated saline, dried over anhydrous sodium sulfate and then concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane-ethyl acetate) to obtain the title compound (2.42 g).

1. customto separate the aqueous and organic layers
2. extractionThe aqueous layer was subjected to extraction with ethyl acetate
3. washwashed with saturated saline
4. dry with materialdried over anhydrous sodium sulfate
5. concentrationconcentrated under reduced pressure
6. customThe obtained residue was purified by silica gel column chromatography (hexane-ethyl acetate)