反应详情

To a solution of 3.30 g (7.21 mmol) of the crude product from Step C dissolved in 40 mL of anhydrous THF was added 1.75 g (10.8 mmol) of 1,1'-carbonyldiimidazole and the reaction mixture was magnetically stirred and heated at reflux for 10 minutes. The reaction was then cooled to room temperature, 2.15 g (10.8 mmol) of 4-iso-propylbenzenesulfonamide and 1.61 mL (10.8 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene were added and the reaction was stirred for an additional 30 minutes at room temperature. The mixture was then diluted with EtOAc (80 mL), washed with 10% aqueous citric acid, saturated aqueous NaCl, dried (MgSO4), filtered and evaporated. The residue was partially purified on a silica gel flash chromatography column eluted with CHCl3 --MeOH--NH4OH (92:8:0.5). The semi-purified material was combined and repurified on a second silica gel flash chromatography column eluted initially with 35% EtOAc-hexane, later with 50% EtOAc-hexane, and finally with 70% EtOAc-hexane. Combination of the purified fractions and evaporation afforded 3.20 g (69%) of the title compound as a yellow oil.

1. temperatureheated
2. temperatureat reflux for 10 minutes
3. stirringthe reaction was stirred for an additional 30 minutes at room temperature
4. washwashed with 10% aqueous citric acid, saturated aqueous NaCl
5. dry with materialdried (MgSO4)
6. filtrationfiltered
7. customevaporated
8. customThe residue was partially purified on a silica gel flash chromatography column
9. washeluted with CHCl3 --MeOH--NH4OH (92:8:0.5)
10. customrepurified on a second silica gel flash chromatography column
11. washeluted initially with 35% EtOAc-hexane, later with 50% EtOAc-hexane
12. customCombination of the purified fractions and evaporation