反应详情

5-bromo-2-chloropyridin-3-amine (1.889 g, 9.1 mmol) was dissolved in isopropyl acetate (20 ml) and acetone (0.81 ml, 11 mmol), trifluoroacetic acid (1.40 ml, 18 mmol), and sodium triacetoxyborohydride (2.34 g, 11 mmol) were added. The reaction was stirred under nitrogen at room temperature for almost 4.5 hours and then quenched with 10% sodium hydroxide in water (˜20 ml) to raise the pH to about 9. The layers were separated, and the aqueous phase was extracted with EtOAc. The organic extracts were combined, dried over sodium sulfate, filtered, concentrated, and dried under high vacuum to afford 5-bromo-2-chloro-N-isopropylpyridin-3-amine (2.33 g, 89% purity, 100% yield). MS (ESI pos. ion) m/z: 249 (MH+, 79Br), 251 (MH+, 81Br). Calculated exact mass for C8H10BrClN2 248 (79Br), 250 (81Br).

1. customquenched with 10% sodium hydroxide in water (˜20 ml)
2. temperatureto raise the pH to about 9
3. customThe layers were separated
4. extractionthe aqueous phase was extracted with EtOAc
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. customdried under high vacuum