Pyridine → 4-Bromo-3-nitrobenzaldoxime

Participants

Reaction Steps

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).

Provenance & Evidence