反应详情

温度

70 °C

To a suspension of crude 5-bromo-4-methyl-pyridine-2-carboxylic acid (10.9 g, approximately 35.5 mmol) in ethanol (120 mL), H2SO4 (0.5 mL) is added. The mixture is stirred at 70° C. for 18 h. The pH of the clear solution is adjusted to pH 9 by adding sat. aq. NaHCO3-solution and the mixture was extracted with diethyl ether (3×300 mL). The combined org. extracts are dried over MgSO4, filtered and concentrated to give 5-bromo-4-methyl-pyridine-2-carboxylic acid ethyl ester (8.20 g) as a green oil; LC-MS: tR=0.87 min, [M+1]+=243.91.

1. additionis added
2. extractionthe mixture was extracted with diethyl ether (3×300 mL)
3. dry with materialextracts are dried over MgSO4
4. filtrationfiltered
5. concentrationconcentrated