反应详情

A 10 mL rb flask equipped with a magnetic stir bar was charged with 0.227 g (0.52 mmol) of the product of Example 89, 0.101 g (0.57 mmol) of N-bromosuccinimide, 3 mL CCl4 and ca. 5 mg of 2,2′-azobisisobutyronitrile (AIBN). The reaction mixture was heated to reflux under a nitrogen atmosphere for 2 h then cooled to room temperature and filtered. The filtrate was evaporated in vacuo, and the residue was then redissolved in 2 mL of DMSO. The solution containing the crude bromination product was transferred to a 10 mL reaction tube of a CEM Corporation Discover 300 Watt microwave reactor and 73 mg (0.62 mmol) of N-methylmorpholine-N-oxide was added. The reaction vessel was sealed, placed in the microwave reactor and heated at 150° C. for 2–3 min. After the reaction mixture had cooled to room temperature, it was partitioned between EtOAc and 10% aq. NaHSO4 and extracted. The organic layer was washed with 10% aq. NaHSO4, water, brine, dried (MgSO4), filtered and evaporated. The residue was purified on a silica gel flash chromatography column eluted with 0–10% EtOAc-hexane. Evaporation of the purified fractions and drying in vacuo afforded the title compound. HPLC/MS: 452.1 (M+1), 454.0 (M+3); Rt=4.63 min.

1. customA 10 mL rb flask equipped with a magnetic stir bar
2. temperatureThe reaction mixture was heated
3. temperatureto reflux under a nitrogen atmosphere for 2 h
4. filtrationfiltered
5. customThe filtrate was evaporated in vacuo
6. dissolutionthe residue was then redissolved in 2 mL of DMSO
7. additionThe solution containing the crude bromination product
8. additionwas added
9. customThe reaction vessel was sealed
10. temperatureheated at 150° C. for 2–3 min
11. temperatureAfter the reaction mixture had cooled to room temperature
12. customit was partitioned between EtOAc and 10% aq. NaHSO4
13. extractionextracted
14. washThe organic layer was washed with 10% aq. NaHSO4, water, brine
15. dry with materialdried (MgSO4)
16. filtrationfiltered
17. customevaporated
18. customThe residue was purified on a silica gel flash chromatography column
19. washeluted with 0–10% EtOAc-hexane
20. customEvaporation of the purified fractions
21. customdrying in vacuo