反应详情

温度

-78 °C

To a 250 mL round bottom flask was added tetrahydrofuran (10 mL) and diisopropylamine (1.04 mL, 7.33 mmol) under nitrogen. The flask was cooled down to −20° C. before addition of n-BuLi (2.93 mL, 7.33 mmol). The reaction was stirred at this temperature for 5 min before being cooled to −78° C. 2,4-dibromothiazole (1.782 g, 7.33 mmol) was added at once to the reaction mixture. After stirring at −78° C. for 10 min, (R,E)-N-((S)-2-(2,3-difluorophenyl)hex-5-enylidene)-2-methylpropane-2-sulfinamide (1.1494 g, 3.67 mmol) in 5 mL tetrahydrofuran was added to the reaction mixture via cannula. The reaction was allowed to continue to stir while it was gradually warmed up to −60° C. (4 h). The reaction was cooled down to −78° C. and n-BuLi (2.93 mL, 7.33 mmol) was added at −78° C. The reaction was stirred for 20 min. Methanol (0.44 mL, 11.0 mmol)l was added to quench the reaction. The reaction was stirred at rt for 0.5 h. The solvent was removed under vacuum and the crude mixture was partitioned between ethyl acetate and water. The ethyl acetate layer was separated, dried (sodium sulfate), filtered and concentrated. Flash chromatography using ethyl acetate in hexane from 0 to 50% to 85% gave the desired product (1.08 g, 62%) as a brown oil, which was solidified upon standing at room temperature overnight: MS (ESI)[M+H+]=479.12. 1H NMR showed a mixture of two diastereomers with a ratio of 3/1 (epimerized 1 from previous reactions).

1. stirringAfter stirring at −78° C. for 10 min
2. stirringto stir while it
3. temperaturewas gradually warmed up to −60° C. (4 h)
4. temperatureThe reaction was cooled down to −78° C.
5. stirringThe reaction was stirred for 20 min
6. customto quench
7. customthe reaction
8. stirringThe reaction was stirred at rt for 0.5 h
9. customThe solvent was removed under vacuum
10. customthe crude mixture was partitioned between ethyl acetate and water
11. customThe ethyl acetate layer was separated
12. dry with materialdried (sodium sulfate)
13. filtrationfiltered
14. concentrationconcentrated