反应详情

To a solution of 3,5-dichloropyridine (796 mg, 5.38 mmol) in THF (9.0 mL) at −78° C. was added lithium diisopropylamide (2.0 M heptane/THF/ethylbenzene, 3.41 mL, 6.82 mmol) dropwise. After stirring for 1 h at this temperature, a solution of (R)-5,5-dimethyltetrahydro-3H-pyrrolo[1,2-c][1,2,3]oxathiazole 1,1-dioxide (686 mg, 3.59 mmol) in THF (9.0 mL) was added dropwise at −78° C. and the mixture was allowed to warm to room temperature over 3 h and then stirred at room temperature for 4 h. After evaporation of the solvent, the resulting beige foam was treated with hot (80° C.) 2 N HCl (8 mL) and EtOH (8 mL) overnight. The reaction mixture was concentrated under reduced pressure (rotary evaporator) and the mixture was treated with ice and basified with 5 N NaOH (8 mL) and extracted with EtOAc (2×75 mL). The organic extracts were dried, evaporated and purified by chromatography on an ISCO Combiflash™ RF (25 g Thomson SingleStep column, using a gradient of 0-10% MeOH in DCM) affording (R)-3,5-dichloro-4-((4,4-dimethylpyrrolidin-2-yl)methyl)pyridine (748 mg, 2.89 mmol, 80% yield) as an orange oil. MS (ESI) 259.1, 261.0 [M+H]+.

1. stirringstirred at room temperature for 4 h
2. customAfter evaporation of the solvent
3. additionthe resulting beige foam was treated with hot (80° C.) 2 N HCl (8 mL) and EtOH (8 mL) overnight
4. concentrationThe reaction mixture was concentrated under reduced pressure (rotary evaporator)
5. additionthe mixture was treated with ice
6. extractionextracted with EtOAc (2×75 mL)
7. customThe organic extracts were dried
8. customevaporated
9. custompurified by chromatography on an ISCO Combiflash™ RF (25 g Thomson SingleStep column