反应详情

温度

75 °C

A mixture of 2.4 g of 2,6-dimethyl-4-nitropyridine 1-oxide and 16.5 mL of acetyl bromide was stirred at 75° C. under a CaCl2 drying tube for 4 h. The mixture was added to ice with H2O, CHCl3, and EtOAc and solid NaHCO3 was added to pH=7-8. The aqueous layer was extracted with CHCl3 (3×), and the combined extracts were dried over Na2SO4, filtered, and concentrated. Purification by flash silica gel chromatography (1 to 5) % MeOH/CHCl3 provided 1.39 g of 4-bromo-2,6-dimethylpyridine 1-oxide as a pale brown solid in 48% yield.

1. additionwas added to pH=7-8
2. extractionThe aqueous layer was extracted with CHCl3 (3×)
3. dry with materialthe combined extracts were dried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated
6. customPurification by flash silica gel chromatography (1 to 5) % MeOH/CHCl3