反应详情

温度

80 °C

Compound 19 (2.18 g, 8.13 mmol) and N-bromosuccinimide (1.70 g, 9.50 mmol) was suspended in 60 mL of CCl4. Dibenzoyl peroxide (20 mg) was added and the mixture was refluxed for 1.5 hr. After removing the solid, the filtrate was washed with concentrated sodium bicarbonate and dried over sodium sulfate. 1H NMR showed the crude material contained 70% of monobrominated and 30% of dibrominated product. This material was dissolved in 20 mL of DMSO and sodium azide (3.70 g, 57 mmol) was added. The mixture was heated to 80° C. for 4 hr before being poured into a mixture of methylene chloride and water. The organic layer was dried and evaporated. The residue was purified by flash column chromatography (5% of ethyl acetate in hexane) to give 20 (2.14 g, 78%, two steps) as colorless oil. 1H NMR (CDCl3) δ 8.22 (s, 1H), 8.00 (d, 7.7 Hz, 1H), 7.76 (d, 8.2 Hz, 1H), 7.58 (m, 2H), 7.50 (m, 2H), 7.33 (d, 7.6 Hz, 1H), 4.43 (s, 2H), 1.62 (s, 9H). 13C NMR (CDCl3) δ 165.2, 140.5, 140.3, 135.8, 132.3, 130.7, 129.1, 128.5, 128.2, 127.8, 127.1, 126.7, 126.6, 80.9, 54.3, 27.8.

1. temperaturethe mixture was refluxed for 1.5 hr
2. customAfter removing the solid
3. washthe filtrate was washed with concentrated sodium bicarbonate
4. dry with materialdried over sodium sulfate
5. dissolutionThis material was dissolved in 20 mL of DMSO
6. customThe organic layer was dried
7. customevaporated
8. customThe residue was purified by flash column chromatography (5% of ethyl acetate in hexane)