反应详情

温度

-78 °C

A solution of n-butyllithium in hexanes (1.65 M, 5.2 mL) was added dropwise to a solution of 4-bromo-N,N-bis(trimethylsilyl)aniline (2.55 mL) in THF (14 mL) at −78° C. The resulting mixture was stirred for 1.5 h at −78° C. before a solution of N-isopropylidene-2-methylpropane-2-sulfinamide in THF (2.8 mL) was added dropwise at −78° C. The reaction mixture was stirred for an additional 1 h at −78° C. then allowed to warm to room temperature. After being stirred for 18 h at room temperature, the reaction mixture was poured into ice cooled saturated sodium bicarbonate solution. The aqueous layer was extracted with ethyl acetate. The combined organic layer was washed with saturated sodium bicarbonate solution and brine and then dried over anhydrous sodium sulfate. The dried solution was filtered and the filtrate was concentrated to dryness. The residue was diluted with diisopropylether and extracted with 1 M citric acid solution. The aqueous extracts were combined and basified with sodium bicarbonate solid to pH>7. The basic aqueous layer was extracted with ethyl acetate and the organic layer was washed with brine. The organics were dried over anhydrous sodium sulfate and concentrated under reduced pressure. Purification by column chromatography (50-100% ethyl acetate in hexanes) gave the product (173 mg, 12%). 400 M Hz 1H-NMR (CDCl3) δ: 7.26 (d, J=8.7 Hz, 2H), 6.65 (d, J=8.7 Hz, 2H), 3.66 (brs, 1H), 3.31 (s, 1H), 1.67 (s, 3H), 1.64 (s, 3H), 1.20 (s, 9H).

1. additionwas added dropwise at −78° C
2. temperatureto warm to room temperature
3. stirringAfter being stirred for 18 h at room temperature
4. additionthe reaction mixture was poured into ice cooled saturated sodium bicarbonate solution
5. extractionThe aqueous layer was extracted with ethyl acetate
6. washThe combined organic layer was washed with saturated sodium bicarbonate solution and brine
7. dry with materialdried over anhydrous sodium sulfate
8. filtrationThe dried solution was filtered
9. concentrationthe filtrate was concentrated to dryness
10. additionThe residue was diluted with diisopropylether
11. extractionextracted with 1 M citric acid solution
12. extractionThe basic aqueous layer was extracted with ethyl acetate
13. washthe organic layer was washed with brine
14. dry with materialThe organics were dried over anhydrous sodium sulfate
15. concentrationconcentrated under reduced pressure
16. customPurification by column chromatography (50-100% ethyl acetate in hexanes)