反应详情

4-Fluoro-3-methoxybenzoic acid (1.00 g, 5.87 mmol) (from Example 34b supra) was dissolved in toluene (30 mL). Triethylamine (3.2 mL, 23.48 mmol) (Fisher), diphenyl phosphoryl azide (2.5 mL, 11.74 mmol) (Aldrich) and tert-butanol (6 mL) (Fisher) were successively added at room temperature. The reaction mixture was heated at reflux for 2 hours, then quenched at room temperature with 1 N aqueous hydrochloric acid (20 mL). The mixture was extracted with ethyl acetate and the layers were separated. The organic layer was washed with saturated aqueous sodium bicarbonate solution and brine, then dried over anhydrous sodium sulfate and filtered. Concentration under reduced pressure gave a yellow oil that was purified by flash chromatography (20% ethyl acetate in hexanes) to give (tert-butoxy)-N-(4-fluoro-3-methoxyphenyl)carboxamide as a white solid. (Yield 0.98 g, 70%).

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 2 hours
3. customquenched at room temperature with 1 N aqueous hydrochloric acid (20 mL)
4. extractionThe mixture was extracted with ethyl acetate
5. customthe layers were separated
6. washThe organic layer was washed with saturated aqueous sodium bicarbonate solution and brine
7. dry with materialdried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationConcentration under reduced pressure
10. customgave a yellow oil that
11. customwas purified by flash chromatography (20% ethyl acetate in hexanes)