反应详情

温度

-78 °C

A solution of 6-bromo-3H-benzooxazol-2-one (0.9236 g, 4.31 micromoles) in anhydrous tetrahydrofuran (25 mL) and dimethylformamide (3 mL) under nitrogen was cooled to −78° C. before addition of n-butyllithium (2.5M in hexane) (3.8 mL, 2.2 equiv). After stirring for 10 min at −78° C., 24 mL of sec-butyllithium (1.4 M in cyclohexane, 8 equiv) was added. The reaction was stirred while slowly warming to −40° C. When this temperature was reached, the reaction was quenched by addition of methanol. The reaction mixture was concentrated in vacuo and water was added. The aqueous layer was acidified with 1N HCl (ca. pH 5) and extracted with ethyl acetate (3×50 mL), dried over sodium sulfate, filtered and concentrated to give the product, 0.6402 g (91%). MS (ESI) 164 (MH)+. 1H NMR (400 MHz, DMSO-d6) δ 9.90 (1H, s), 7.79 (1H, d, J=8.0 Hz), 7.74 (1H, s), 7.28 (1H, d, J=8.0 Hz).

1. stirringThe reaction was stirred
2. temperaturewhile slowly warming to −40° C
3. customthe reaction was quenched by addition of methanol
4. concentrationThe reaction mixture was concentrated in vacuo and water
5. additionwas added
6. extractionextracted with ethyl acetate (3×50 mL)
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customto give the product, 0.6402 g (91%)