反应详情

A suspension of Intermediate 74a (5.00 g, 35.7 mmol) in acetonitrile (90 mL) was treated with iodine (9.10 g, 35.7 mmol) then ceric ammonium nitrate (19.6 g, 35.7 mmol) and the mixture was stirred at RT overnight. Another portion of iodine (2.28 g, 9.0 mmol) was added and the mixture was stirred for a further 24 h then treated with ice-cold aqueous sodium hydrogensulphite solution (5%, 100 mL). The mixture was filtered through Celite rinsing with EtOAc and water. The phases were separated and the aqueous phase was extracted with EtOAc (2×). The combined organic layers were washed with water and brine, dried (Na2SO4), filtered and evaporated in vacuo. The resulting solid was triturated with ether/cyclohexane, filtered off, washed with cyclohexane and dried at 50° C. in vacuo to give the title compound (3.70 g, 39%). LCMS (Method 3): Rt 2.88 min, m/z 267 [MH+] (weak).

1. filtrationThe mixture was filtered through Celite
2. washrinsing with EtOAc and water
3. customThe phases were separated
4. extractionthe aqueous phase was extracted with EtOAc (2×)
5. washThe combined organic layers were washed with water and brine
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. customevaporated in vacuo
9. customThe resulting solid was triturated with ether/cyclohexane
10. filtrationfiltered off
11. washwashed with cyclohexane
12. customdried at 50° C. in vacuo