Reacción #680655

Ecuación de reacción

NaHCO3

Boron trifluoride etherate

5,5,5-trifluoropentanoic acid

tert-butyl 2,2,2-trichloroacetimidate

→

tert-Butyl 5,5,5-trifluoropentanoate

Rendimiento 98.0%

Disolventes

THF

hexane

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturato warm to room temperature overnight
2. 2
   workup.STIRRINGstirred for 30 min
3. 3
   FiltraciónThe mixture was filtered through MgSO4
4. 4
   Lavadowashed with hexanes (200 mL)
5. 5
   workup.WAITto rest for 45 min
6. 6
   Otrothe resulting solid material was removed
7. 7
   Filtraciónby filtering on the same MgSO4
8. 8
   Filtraciónfilter again
9. 9
   Lavadowashed with hexanes (100 mL)
10. 10
    Concentraciónconcentrated under reduced pressure
11. 11
    Temperaturawithout heat
12. 12
    Filtraciónfiltered through a clean fritted funnel
13. 13
    Lavadowashed with hexane (5 mL)
14. 14
    Concentraciónconcentrated under reduced pressure
15. 15
    Temperaturawithout heat
16. 16
    FiltraciónThe resulting neat oil was filtered through a 0.45 μm nylon membrane
17. 17
    Filtraciónfilter disk
18. 18
    Otroto provide Intermediate S-1G (6.6 g, 31.4 mmol 98% yield) as a colorless oil

Procedimiento

To a stirred solution of 5,5,5-trifluoropentanoic acid (5 g, 32.0 mmol) in THF (30 mL) and hexane (30 mL) at 0° C., was added tert-butyl 2,2,2-trichloroacetimidate (11.46 mL, 64.1 mmol). The mixture was stirred for 15 min at 0° C. Boron trifluoride etherate (0.406 mL, 3.20 mmol) was added and the reaction mixture was allowed to warm to room temperature overnight. To the clear reaction mixture was added solid NaHCO3 (5 g) and stirred for 30 min. The mixture was filtered through MgSO4 and washed with hexanes (200 mL). The solution was allowed to rest for 45 min, and the resulting solid material was removed by filtering on the same MgSO4 filter again, washed with hexanes (100 mL) and concentrated under reduced pressure without heat. The volume was reduced to about 30 mL, filtered through a clean fritted funnel, washed with hexane (5 mL), and then concentrated under reduced pressure without heat. The resulting neat oil was filtered through a 0.45 μm nylon membrane filter disk to provide Intermediate S-1G (6.6 g, 31.4 mmol 98% yield) as a colorless oil: 1H NMR (400 MHz, CDCl3) δ ppm 1.38 (s, 9 H) 1.74-1.83 (m, 2 H) 2.00-2.13 (m, 2 H) 2.24 (t, J=7.28 Hz, 2 H).

Fuente