反应详情

温度

40 °C

A mixture of 5-bromo-2,3-difluorobenzaldehyde (17.38 g, 78.6 mmol), O-methylhydroxylamine hydrochloride (7.23 g, 86.46 mmol), and K2CO3 (13 g, 94.32 mmol) in DME (80 mL) was heated at 40° C. for 14 h. Work-up: the reaction mixture was filtered. The filtrate was concentrated in vacuo, and the residue was purified by column chromatography on silica gel (0˜2% EtOAc in petroleum ether), to give (E)-5-bromo-2,3-difluorobenzaldehyde O-methyl oxime (19.65 g). 1H NMR (CDCl3, 300 MHz): δ 8.20 (s, 1H), 7.76-7.73 (m, 1H), 7.35-7.29 (m, 1H), 4.01 (s, 3H).

1. filtrationthe reaction mixture was filtered
2. concentrationThe filtrate was concentrated in vacuo
3. customthe residue was purified by column chromatography on silica gel (0˜2% EtOAc in petroleum ether)