反应详情

温度

0 °C

To a cold (−78° C.) of diisopropylamine (3.44 mL, 24.5 mmol) in tetrahydrofuran (49 mL) was added n-butyl lithium (2.5 M in hexanes, 9.81 mL, 24.5 mmol) dropwise over 10 minutes. The ice bath was removed, and the reaction mixture was allowed to warm to 0° C. and then cooled back to ±78° C. A solution of Example 45B (3.3 g, 12.3 mmol) in tetrahydrofuran (10 mL) was then added. The ice bath was removed and the reaction mixture was heated at 50° C. for 2 hours. The reaction mixture was then cooled back to ±78° C. and methyl iodide (0.84 mL, 13.5 mmol) was added followed by stirring for 2 hours. The cooling bath was removed, and the reaction mixture was stirred at room temperature for 1 hour. The reaction solution was then poured into diethyl ether (200 mL) and 1M HCl (200 mL). The layers were separated and the aqueous layer was further extracted with diethyl ether (2×200 mL). The combined organic layers were dried over sodium sulfate, filtered and concentrated to a crude yellow oil. The crude oil was purified by flash chromatography with 15% ethyl acetate/84% hexane/1% methanol to afford the titled compound (2.37 g) as a light yellow oil. MS (CI) m/z 273 (M+1)+.

1. customThe ice bath was removed
2. temperaturecooled back
3. customto ±78° C
4. customThe ice bath was removed
5. temperaturethe reaction mixture was heated at 50° C. for 2 hours
6. temperatureThe reaction mixture was then cooled back
7. customto ±78° C.
8. customThe cooling bath was removed
9. stirringthe reaction mixture was stirred at room temperature for 1 hour
10. additionThe reaction solution was then poured into diethyl ether (200 mL) and 1M HCl (200 mL)
11. customThe layers were separated
12. extractionthe aqueous layer was further extracted with diethyl ether (2×200 mL)
13. dry with materialThe combined organic layers were dried over sodium sulfate
14. filtrationfiltered
15. concentrationconcentrated to a crude yellow oil
16. customThe crude oil was purified by flash chromatography with 15% ethyl acetate/84% hexane/1% methanol