反应详情

5-Bromo-3-fluoropicolinic acid (1.4 g, 6.5 mmol), N,O-dimethylhydroxylamine.HCl (0.82 g, 8.45 mmol), (2-(7-aza-1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) (3.2 g, 8.45 mmol) and triethylamine (2.3 mL, 16.3 mmol) were stirred in DMF (30 mL) at room temperature for 1 d. EtOAc and sat. aq. Na2CO3 solution was added and the aqueous phase extracted with EtOAc. The combined organics were washed with brine, dried (MgSO4), filtered and concentrated in vacuo. The residue was purified by column chromatography using silica gel and eluting with 20-80% EtOAc in isohexane to afford 5-bromo-3-fluoro-N-methoxy-N-methylpicolinamide.

1. extractionthe aqueous phase extracted with EtOAc
2. washThe combined organics were washed with brine
3. dry with materialdried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customThe residue was purified by column chromatography
7. washeluting with 20-80% EtOAc in isohexane