反应详情

To a solution of 4-fluoro-1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-6-carbaldehyde (1.86 g, 8.94 mmol) and NH2OH.HCl (0.69 g, 9.84 mmol) in THF (16 mL) and H2O (4 mL) at rt was added NaOAc (0.92 g, 11.18 mmol). The reaction mixture was stirred for 3 h and diluted with H2O. The mixture was extracted with EA and the organic layer was separated. The organic solution was washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel eluted with PE-EA (5:1 to 2:1) to give (E)-4-fluoro-1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-6-carbaldehyde oxime (1.8 g, 95.8% yield) as a light yellow solid. 1H NMR (500 MHz, DMSO-d6) δ 11.38 (s, 1H), 9.34 (s, 1H), 8.19 (s, 1H), 7.74 (s, 1H), 7.46 (dd, J=1.2 Hz, J=11.2 Hz, 1H), 1.524 (s, 6H) ppm.

1. extractionThe mixture was extracted with EA
2. customthe organic layer was separated
3. washThe organic solution was washed with brine
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. customThe residue was purified by column chromatography over silica gel
8. washeluted with PE-EA (5:1 to 2:1)