反应详情

To 12.4 g of potassium tert-butoxide in 79 ml of dimethylsulfoxide, 6.7 g of nitromethane was added dropwise with stirring under cooling with ice, and after the addition, the mixture was stirred at room temperature for another 1 hour. Then, the reaction mixture was added dropwise to 25.0 g of 5-bromo-2,3-dichloropyridine in 20 ml of dimethylsulfoxide with stirring under cooling with ice, and after the addition, the mixture was stirred at room temperature for 23 hours and at 50° C. for 6 hours. After completion of the reaction, the reaction mixture was allowed to cool to room temperature, mixed with 100 ml of water and 100 ml of saturated aqueous ammonium chloride and extracted with ethyl acetate (200 ml×2). The resulting organic layers were combined, washed with water (100 ml×3) and dried over saturated aqueous sodium chloride and then anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography using ethyl acetate-hexane (with a gradient of from 5:95 to 30:70) as the eluent to obtain 7.8 g of the desired product as a pale yellow oil.

1. temperatureunder cooling with ice
2. additionafter the addition
3. stirringthe mixture was stirred at room temperature for another 1 hour
4. stirringwith stirring
5. temperatureunder cooling with ice
6. additionafter the addition
7. stirringthe mixture was stirred at room temperature for 23 hours and at 50° C. for 6 hours
8. customAfter completion of the reaction
9. extractionextracted with ethyl acetate (200 ml×2)
10. washwashed with water (100 ml×3)
11. dry with materialdried over saturated aqueous sodium chloride
12. customanhydrous sodium sulfate, and the solvent was evaporated under reduced pressure
13. customThe resulting residue was purified by silica gel column chromatography