反应详情

温度

95 °C

48.5 g of 2-ethoxy-6-acetylpyridine were introduced into 145 ml of hydrogen bromide solution (30 percent strength solution in glacial acetic acid) and the mixture was heated to 95° C. A further 176 ml of hydrogen bromide solution (30% strength solution in glacial acetic acid) were added dropwise at this temperature. The mixture was stirred for 3 hours at 95° C. and then cooled to room temperature. It was poured into ice-water and neutralized to pH 7 using 50 percent strength aqueous sodium hydroxide solution. The mixture was subsequently extracted 3 times with methyl tert-butyl ether. The aqueous phase was concentrated. The residue which remained was stirred 4 times with acetone. After the combined acetone phases had been concentrated, there remained 38.5 g of 2-hydroxy-6-acetylpyridine as a colorless solid (m.p.: 115-117 C).

1. temperaturecooled to room temperature
2. extractionThe mixture was subsequently extracted 3 times with methyl tert-butyl ether
3. concentrationThe aqueous phase was concentrated
4. stirringThe residue which remained was stirred 4 times with acetone
5. concentrationAfter the combined acetone phases had been concentrated