反应详情

温度

30 °C

To a nitrogen purged, 12 L, 5-necked flask, fitted with an overhead stirrer, a thermocouple and a condenser, was charged ethyl 2-(2,4-difluorophenyl)nicotinate, 3 (144 g, 548 mmoles, 1.0 eq), and 4 L of CH2Cl2. With stirring, mCPBA was added over 5 minutes, and the temperature was gradually increased from 22 to 38° C. in 45 minutes (completeness of reaction determined by HPLC). The reaction was cooled to room temperature and the contents slowly poured into 3 L of water. Na2SO3 was added slowly (exotherm from 20 to 33° C.) until the peroxide test (starch/I2 paper) indicated no peroxides remained in the mixture. The aqueous layer was separated and the organic layer was washed with saturated NaHCO3 (˜3 L). The organic layer was dried with MgSO4, filtered, and concentrated to a brown thick oil. The oil was then treated with MTBE (2 L) and stirred to give a white precipitate, which was collected by filtration, washed with MTBE and dried under vacuum to give the title Compound 4.

1. customTo a nitrogen purged
2. custom12 L, 5-necked flask, fitted with an overhead stirrer
3. custom(completeness of reaction determined by HPLC)
4. temperatureThe reaction was cooled to room temperature
5. customThe aqueous layer was separated
6. washthe organic layer was washed with saturated NaHCO3 (˜3 L)
7. dry with materialThe organic layer was dried with MgSO4
8. filtrationfiltered
9. concentrationconcentrated to a brown thick oil
10. additionThe oil was then treated with MTBE (2 L)
11. stirringstirred
12. customto give a white precipitate, which
13. filtrationwas collected by filtration
14. washwashed with MTBE
15. customdried under vacuum