Sulfuric Acid → (2R)-5,5,5-Trifluoro-2-hydroxypentanoic acid

Temperatur

0 °C

To a cool (0° C.), stirred solution of (2R)-2-amino-5,5,5-trifluoropentanoic acid (4.09 g, 23.90 mmol) (US 2009/0111858 A1) and H2SO4 (2.8 mL, 52.5 mmol) in water (95 mL) was added a solution of sodium nitrite (9.89 g, 143 mmol) in water (30 mL) dropwise via addition funnel over 60 min. The reaction mixture was allowed to slowly warm to room temperature and stirred overnight. The reaction mixture was diluted with Et2O, the aqueous phase was separated and extracted with Et2O (3×). The combined organics were dried (Na2SO4), filtered and concentrated under reduced pressure to provide Intermediate S5B (4.1551 g, >99%) as an amber oil. 1H NMR (400 MHz, CDCl3) δ 4.33 (1H, dd, J=8.03, 4.27 Hz), 2.09-2.42 (3H, m), 1.88-2.02 (1H, m).

1. additiondropwise via addition funnel over 60 min
2. temperatureto slowly warm to room temperature
3. customthe aqueous phase was separated
4. extractionextracted with Et2O (3×)
5. dry with materialThe combined organics were dried (Na2SO4)
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customto provide Intermediate S5B (4.1551 g, >99%) as an amber oil

ORD-Eintrag

ord-82adb25ed1454ea599553b2fa171ce82

Quelldatensatz

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09249157B2