反应详情

To a solution of 4-bromo-3-methyl-benzaldehyde (4.3 g) (Example 1.1) in ethanol (50 ml), were added at ambient temperature hydroxylamine hydrochloride (1.75 g), sodium acetate (2.07 g) and water (15 ml). The reaction mixture was stirred at ambient temperature for 3 hours. The reaction mixture was concentrated and the residue was partitioned between ethyl acetate and aqueous sodium hydroxide (2M). The phases were separated and the organic phase was washed with brine, dried over sodium sulfate, and concentrated. The residue was purified by chromatography on silica gel (eluent: cyclohexane/ethyl acetate 4:1) to give 4-bromo-3-methyl-benzaldehyde oxime (3.65 g) as a white solid. 1H-NMR (400 MHz, CDCl3): 8.05 (s, 1H), 7.50 (m, 2H), 7.25 (d, 1H), 2.40 (s, 3H) ppm.

1. concentrationThe reaction mixture was concentrated
2. customthe residue was partitioned between ethyl acetate and aqueous sodium hydroxide (2M)
3. customThe phases were separated
4. washthe organic phase was washed with brine
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated
7. customThe residue was purified by chromatography on silica gel (eluent: cyclohexane/ethyl acetate 4:1)