反应详情

A solution of cis(±)4-azido-1-(2-hydroxyethyl)piperidin-3-ol (Intermediate 45) (0.4 g, 2.15 mmol) in dry dichloromethane (15 mL) and 2,6-lutidine (0.325 mL, 2.8 mmol) was treated at −20° C. dropwise with a solution of methanesulfonyl chloride (0.175 mL, 2.26 mmol) in dichloromethane (5 mL). The temperature was allowed to reach 0° C. and kept at 0° C. for 10 hours. The resulting reaction mixture was diluted with dichloromethane (50 mL) and washed with saturated aqueous sodium hydrogen carbonate solution (10 mL). The aqueous phase was back extracted with dichloromethane (20 mL) and the combined organic phases were dried over sodium sulfate. The solvent was removed under reduced pressure, and the residue was codistilled with dry DMF (10 mL) without heating. This crude preparation of the mesylate was used without further purification directly for the next step.

1. customto reach 0° C.
2. customThe resulting reaction mixture
3. washwashed with saturated aqueous sodium hydrogen carbonate solution (10 mL)
4. extractionThe aqueous phase was back extracted with dichloromethane (20 mL)
5. dry with materialthe combined organic phases were dried over sodium sulfate
6. customThe solvent was removed under reduced pressure
7. temperaturewithout heating
8. customThis crude preparation of the mesylate
9. customwas used without further purification directly for the next step