反应详情

A mixture of 2,6-dichloro-5-fluoro-3-pyridinecarboxylic acid (3.00 g, 0.0143 mol), anhydrous sodium acetate (3.516 g, 0.0429 mol), and 10% palladium-on-carbon (0.300 g) in methanol (50 mL) was hydrogenated at 1 atmosphere hydrogen pressure (balloon) for 18 hours. The reaction was vacuum filtered through a 0.45μ PTFE membrane and the catalyst thoroughly washed with methanol (25 mL). The filtrate was concentrated by rotary evaporation in vacuo. The residue was taken up in ethyl acetate (100 mL) and water (30 mL), the aqueous pH adjusted to 3 with 6N aqueous hydrochloric acid, and the layers separated. The organic phase was washed with water (2×30 mL) and brine (30 mL), then dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. This afforded the title compound as a white solid (1.293 g, 64%).

1. filtrationfiltered through a 0.45μ PTFE membrane
2. washthe catalyst thoroughly washed with methanol (25 mL)
3. concentrationThe filtrate was concentrated by rotary evaporation in vacuo
4. customthe layers separated
5. washThe organic phase was washed with water (2×30 mL) and brine (30 mL)
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo