Lithium Hydroxide → 1-((Tert-butoxy)carbonyl)-4,4-difluoropiperidine-2-carboxylic acid

To a solution of 1-tert-butyl 2-methyl 4,4-difluoropiperidine-1,2-dicarboxylate, 13e, (4.6 g, 16.5 mmol) in THF (18 mL), methanol (18 mL) and H2O (9 mL) was added lithium hydroxide (3.45 g, 82.22 mmol). The reaction mixture was stirred at room temperature for 1 hour. All volatiles were removed under reduced pressure. The residue was diluted with a slight amount of water and ether. The layers were separated and the organic phase was discarded. The aqueous phase was acidified to pH 3 with the addition of aqueous saturated KHSO4 solution. The product was extracted with EtOAc. The organic phase was washed with water, dried over MgSO4, filtered and evaporated to dryness. The resulting product was used without further purification.

1. customAll volatiles were removed under reduced pressure
2. additionThe residue was diluted with a slight amount of water and ether
3. customThe layers were separated
4. additionThe aqueous phase was acidified to pH 3 with the addition of aqueous saturated KHSO4 solution
5. extractionThe product was extracted with EtOAc
6. washThe organic phase was washed with water
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. customevaporated to dryness
10. customThe resulting product was used without further purification

ORDレコード

ord-910c428627e94b36b31a19ee463a1cbb

出典データセット

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US09345708B2