反应详情

温度

-78 °C

To a solution of anhydrous THF (150 ml) containing compound 20A (3.0 g, 13.4 mmol, prepared accordingly to Bioorganic & Medicinal Chemistry, 4, 1996, 227-237) was added 2.1 eq n-BuLi (11.2 ml, 2.5 M in hexane) dropwise at −78° C. under N2. After the addition, the resulting solution was stirred for 2 hours at −78° C. At this temperature 1.1 eq methyldisulfanyl methane (1.33 ml) was added and the resulting solution was stirred for 1 hour at −78° C. and subsequently allowed to warm to ambient temperature overnight. Then the mixture was quenched with a saturated NH4Cl solution at 0° C. and concentrated in vacuo. Ethyl acetate was added and the organic layer was washed with 5% NaHCO3, dried (Na2SO4), filtered and concentrated in vacuo. Purification by flash chromatography (ethyl acetate) afforded compound 21A (oil, 1.71 g, 67%). 1H-NMR (200 MHz, CDCl3): δ 9.18 (d, J=2 Hz, 1H), 8.60 (dd, J=5 Hz, 2 Hz, 1H), 8.28 (dt, J=8 Hz, 2 Hz, 1H), 7.70 (s, 1H), 7.42-7.33 (m, 1H), 2.38 (s, 3H).

1. customprepared accordingly to Bioorganic & Medicinal Chemistry, 4, 1996, 227-237)
2. additionAfter the addition
3. stirringthe resulting solution was stirred for 1 hour at −78° C.
4. temperatureto warm to ambient temperature overnight
5. customThen the mixture was quenched with a saturated NH4Cl solution at 0° C.
6. concentrationconcentrated in vacuo
7. additionEthyl acetate was added
8. washthe organic layer was washed with 5% NaHCO3
9. dry with materialdried (Na2SO4)
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customPurification by flash chromatography (ethyl acetate)