反应详情

To a solution of 4-bromo-3-nitro-benzaldehyde (commercially available) (10 g, 43.5 mmol) in methanol (28 ml) under a nitrogen atmosphere was added pyridine (7.74 g, 97.8 mmol) and hydroxylamine hydrochloride (6.04 g, 86.94 mmol). The reaction mixture was stirred at ambient temperature for 16 hours. The reaction mixture was diluted with a mixture of ethyl acetate and aqueous sodium hydrogen carbonate (saturated). The phases were separated and the aqueous phase was extracted twice with ethyl acetate. The combined organic phases were dried over sodium sulfate and concentrated. The residue was purified by column chromatography on silica gel (eluent: ethyl acetate/cyclohexane 1:3) to give 4-bromo-3-nitro-benzaldehyde oxime (5.34 g, 67% yield). 1H-NMR (CDCl3, 400 MHz): 8.11 (s, 1H), 8.05 (d, 1H), 7.75 (d, 1H), 7.62 (m, 2H).

1. customThe phases were separated
2. extractionthe aqueous phase was extracted twice with ethyl acetate
3. dry with materialThe combined organic phases were dried over sodium sulfate
4. concentrationconcentrated
5. customThe residue was purified by column chromatography on silica gel (eluent: ethyl acetate/cyclohexane 1:3)