反应详情

To a stirred solution of 2 (10.12 g, 5.59 mmol) in dry THF (200 ml) at −78° C. was added n-BuLi (24 ml, 76.7 mmol, 2.5 M solution in hexanes) and the resultant suspension was stirred for 15 minutes. Bromine (18.9 g, 120 mmol) was added slowly and the reaction mixture was stirred for additional 30 minutes, quenched with water and diluted with EtOAc. The organic phase was separated and dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. Purification by column chromatography (eluent EtOAc/Hexane 9:1) afforded title compound 49 (10.5 g, 71% yield) as a yellow solid. 1H NMR (CDCl3) δ (ppm): 8.62 (d, J=5.09 Hz, 1H), 7.92 (s, 1H), 7.59 (d, J=5.09 Hz, 1H).

1. customquenched with water
2. additiondiluted with EtOAc
3. customThe organic phase was separated
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. customPurification by column chromatography (eluent EtOAc/Hexane 9:1)