反应详情

Intermediate 2 (45.0 g, 0.212 mol, 1 eq.) was dissolved in DCM (225 mL), pyridine (80 mL, 0.989 mol, 6 eq.) was added and the mixture was cooled in an ice bath under nitrogen. Acetic anhydride (100 mL, 1.06 mol, 4 eq.) was added slowly via addition funnel. The mixture was stirred (−3 hr) until reaction was complete and then diluted with diethyl ether (500 mL) and washed with 1N HCl (4×250 mL). The mixture was extracted into 8% sodium bicarbonate solution (4×80 mL), acidified to ˜pH 4 with 6N HCl, and the product extracted into diethyl ether, giving 41.1 g of intermediate 3 as a white crystalline solid.

1. temperaturethe mixture was cooled in an ice bath under nitrogen
2. customuntil reaction
3. washwashed with 1N HCl (4×250 mL)
4. extractionThe mixture was extracted into 8% sodium bicarbonate solution (4×80 mL)
5. extractionthe product extracted into diethyl ether