反应详情

To a solution of 2.19 g (5.38 mmol) of the product of Step C dissolved in 20 mL of anhydrous THF was added 2.41 mL (16.1 mmol) of 1,8-diazabicyclo[5.4.0]undec-7-ene and the reaction mixture was magnetically stirred under a nitrogen atmosphere for 25 minutes at room temperature. Iodomethane (1.00 mL; 16.1 mmol) was added and the reaction mixture was stirred an additional 15 hours at room temperature. The reaction mixture was diluted with EtOAc and a precipitate formed which was redissolved by addition of methanol. The mixture was further diluted with warm EtOAc (150 mL total), refrigerated overnight and a solid separated which was removed by filtration. The filtrate was evaporated in vacuo and the residue was purified on a silica gel flash chromatography column eluted with 5% EtOAc--CHCl3. Combination of the purified fractions and evaporation in vacuo afforded 0.164 g of the title compound and a number of impure fractions which were reserved for repurification.

1. stirringthe reaction mixture was stirred an additional 15 hours at room temperature
2. customa precipitate formed which
3. customa solid separated which
4. customwas removed by filtration
5. customThe filtrate was evaporated in vacuo
6. customthe residue was purified on a silica gel flash chromatography column
7. washeluted with 5% EtOAc
8. customCombination of the purified fractions and evaporation in vacuo