Reaktion #484790

Reaktionsgleichung

acetaldehyde

1-benzyl-4-piperidone

morpholine

1-benzyl-4-morpholino-1,2,5,6-tetrahydropyridine

→

1-benzyl-3-(1-hydroxyethyl)-4-piperidone

Ausbeute 69.7%

Lösungsmittel

methylene chloride

Water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturunder heating
2. 2
   Temperaturreflux
3. 3
   SonstigeAfter completion of the reaction
4. 4
   workup.DISTILLATIONthe solvent was distilled off under reduced pressure, whereby 13.7 g of 1-benzyl-4-morpholino-1,2,5,6-tetrahydropyridine
5. 5
   Sonstigewere quantitatively obtained
6. 6
   Sonstigeobtained above
7. 7
   workup.ADDITIONAfter completion of the dropwise addition
8. 8
   Temperaturthe temperature was gradually raised
9. 9
   Sonstigeto terminate
10. 10
    Sonstigethe reaction
11. 11
    Extraktionfollowed by extraction with methylene chloride
12. 12
    WaschenThe organic layer was washed with saturated saline
13. 13
    Trocknendried over anhydrous sodium sulfate
14. 14
    Einengenconcentrated under reduced pressure
15. 15
    WaschenThe residue was subjected to chromatography on a silica gel column (eluting solvent: toluene/ethyl acetate=4/1)

Vorschrift

A 100 ml tolune solution of 10.0 g (52.9 mmol) of 1-benzyl-4-piperidone and 4.61 g (52.9 mmol) of morpholine was subjected to azeotropic dehydration for 5 hours under heating and reflux by using a water separator. After completion of the reaction, the solvent was distilled off under reduced pressure, whereby 13.7 g of 1-benzyl-4-morpholino-1,2,5,6-tetrahydropyridine were quantitatively obtained. In an argon atmosphere, a 20 ml methylene chloride solution of 1.52 g (34.6 mmol) of acetaldehyde was cooled to −40° C., followed by the dropwise addition of 5.3 ml (43 mmol) of a boron trifluoride-ether complex and 7.44 g (28.8 mmol) of the 1-benzyl-4-morpholino-1,2,5,6-tetrahydropyridine obtained above. After completion of the dropwise addition, the temperature was gradually raised and the reaction mixture was allowed to stand overnight at room temperature. Water was added to terminate the reaction, followed by extraction with methylene chloride. The organic layer was washed with saturated saline, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was subjected to chromatography on a silica gel column (eluting solvent: toluene/ethyl acetate=4/1), whereby 4.68 g (yield: 69.7%) of 1-benzyl-3-(1-hydroxyethyl)-4-piperidone were obtained as a yellowish brown oil.

Quelle