Nitrogen → tert-Butyl 3,3-difluoro-4-oxopiperidine-1-carboxylate

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), to an ice-cold solution of tert-butyl 3,3-difluoro-4-hydroxypiperidine-1-carboxylate (2.40 g, 10.00 mmol) in dry CH2Cl2 (50 mL) was added a solution of Dess-Martin periodinane (50 mL of a 15% solution in CH2Cl2, 24.00 mmol). The reaction mixture was stirred at rt until completion of the reaction. Sat. aq. NaHCO3 (50 mL) was then added followed by 10% aq. Na2SO3 (50 mL). The mixture was stirred at rt for 1 h, the layers separated and the aq. layer extracted with CH2Cl2 (3×). The combined org. extracts were dried over MgSO4, filtered, and concentrated under reduced pressure. The crude residue was redissolved in CH2Cl2 (30 mL) and stirred in the presence of molecular sieves for 24 h, filtered, and concentrated under reduced pressure to give tert-butyl 3,3-difluoro-4-oxopiperidine-1-carboxylate as a yellow solid.

1. stirringThe mixture was stirred at rt for 1 h
2. customthe layers separated
3. extractionthe aq. layer extracted with CH2Cl2 (3×)
4. dry with materialextracts were dried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. dissolutionThe crude residue was redissolved in CH2Cl2 (30 mL)
8. stirringstirred in the presence of molecular sieves for 24 h
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure

ORD-Eintrag

ord-12251a9c5177443c8245cc6119a9a323

Quelldatensatz

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09139524B2