Reaktion #156303

Reaktionsgleichung

methanol

tert-butyl 4-[3-(pyridin-3-yl)propanoyl]piperazine-1-carboxylate

borane tetrahydrofuran

→

tert-butyl 4-[3-(pyridin-3-yl)propyl]piperazine-1-carboxylate

Ausbeute 99.7%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooling
2. 2
   TemperaturThe mixture was heated
3. 3
   Temperaturto reflux for 6 hours
4. 4
   Temperaturby further heating
5. 5
   Temperaturto reflux for 16 hours
6. 6
   TemperaturAfter cooling to room temperature
7. 7
   Einengenthe mixture was concentrated under reduced pressure
8. 8
   workup.ADDITIONa mixture of a saturated aqueous sodium hydrogen carbonate solution and ethyl acetate
9. 9
   workup.ADDITIONwas added
10. 10
    SonstigeThe aqueous layer was separated
11. 11
    Waschenthe organic layer was washed with saturated brine
12. 12
    Trocknendried over anhydrous magnesium sulfate
13. 13
    SonstigeThe solvent was evaporated under reduced pressure
14. 14
    Sonstigethe residue was purified by silica gel column chromatography (chloroform/methanol)

Vorschrift

Under a nitrogen atmosphere, to a solution of 1.5 g of tert-butyl 4-[3-(pyridin-3-yl)propanoyl]piperazine-1-carboxylate in 25 mL of tetrahydrofuran was added 7 mL of a 1 M borane/tetrahydrofuran solution under ice-cooling. The mixture was heated to reflux for 6 hours, and then cooled to room temperature, and 10 mL of methanol was added thereto, followed by further heating to reflux for 16 hours. After cooling to room temperature, the mixture was concentrated under reduced pressure, and a mixture of a saturated aqueous sodium hydrogen carbonate solution and ethyl acetate was added thereto. The aqueous layer was separated, and then the organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure and the residue was purified by silica gel column chromatography (chloroform/methanol) to obtain 1.43 g of tert-butyl 4-[3-(pyridin-3-yl)propyl]piperazine-1-carboxylate.

Quelle