反应详情

温度

50 °C

3-Amino-4-bromo-6-chloro-pyridine-2-carboxylic acid methyl ester (169 mg) was suspended in methanol (3 mL) and 2N sodium hydroxide solution (2 mL). The suspension was stirred at 50° C. for 3 hours. The precipitate was filtered off and washed carefully with diethyl ether. The precipitate was dissolved in a mixture of 2N hydrochloric acid and ethyl acetate and the layers were separated. The aqueous layer was 2× extracted with ethyl acetate, washed with brine, dried over MgSO4 and concentrated in vacuum to afford 138 mg of the title compound of the formula

1. filtrationThe precipitate was filtered off
2. washwashed carefully with diethyl ether
3. dissolutionThe precipitate was dissolved in a mixture of 2N hydrochloric acid and ethyl acetate
4. customthe layers were separated
5. extractionextracted with ethyl acetate
6. washwashed with brine
7. dry with materialdried over MgSO4
8. concentrationconcentrated in vacuum