反应详情

To a solution of compound 11 (1.2 g, 4.4 mmol) in THF (100 mL) was added n-BuLi (2.5 M, 3.5 ml) dropwise at −78° C. over 30 minutes and the resulting reaction mixture was stirred below −70° C. for another one hour. Then a solution of iodine (2.2 g, 8.8 mmol) in THF (20 mL) was added dropwise and the dark brown mixture was allowed to warm up to room temperature slowly over one hour. The reaction was quenched with saturated aqueous solution of Na2SO3 (60 mL), and then the mixture was extracted with EtOAc (200 mL×2). The organic layers were combined and dried over Na2SO4, filtered and concentrated in vacuo to give the crude product, which was purified by chromatography on silica gel column (eluted with PE/EtOAc=10:1 to 2:1) to afford compound 12 (450 mg, 25% yield) as a yellow solid. LC-MS: m/z 397 [M+H]+. 1H NMR (400 MHz, CDCl3): δ 8.82 (br. s, 1H), 7.94 (s, 1H), 7.36˜7.32 (m, 5H), 4.65˜4.55 (m, 3H), 1.60 (d, J=6.4 Hz, 3H).

1. customthe resulting reaction mixture
2. customThe reaction was quenched with saturated aqueous solution of Na2SO3 (60 mL)
3. extractionthe mixture was extracted with EtOAc (200 mL×2)
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customto give the crude product, which
8. customwas purified by chromatography on silica gel column (eluted with PE/EtOAc=10:1 to 2:1)