Reaktion #425853

Reaktionsgleichung

4-piperidone ethylene ketal

methyl-3-bromobenzoate

t-BuOH

t-BuOH

cesium carbonate

→

title compound

Ausbeute 97.1%

Methyl-3-(1,4-dioxa-8-azaspiro[4.5]dec-8-yl)-benzoate

Ausbeute 97.1%

Lösungsmittel

toluene

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA thick-walled glass reaction vessel
2. 2
   SonstigeThe stirred contents were purged with nitrogen
3. 3
   Sonstigethe vessel was sealed
4. 4
   TemperaturUpon cooling to room temperature
5. 5
   Filtrationthe reaction mixture was filtered through celite
6. 6
   Einengenthe filtrate was concentrated
7. 7
   WaschenElution through a flash column (silica gel 60, 230-400 mesh, 7:3 hexanes:EtOAc)
8. 8
   Einengenfollowed by concentration

Vorschrift

Procedure adopted from Tetrahedron Lett., 2007, 48, 2519. A thick-walled glass reaction vessel was charged with palladium(II)acetate (235 mg, 1.05 mmol), X-Phos (500 mg, 1.05 mmol, 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl), cesium carbonate (6.82 g, 20.95 mmol) and 5:1 (v/v) toluene:t-BuOH (20 mL). The stirred contents were purged with nitrogen and a solution of 4-piperidone ethylene ketal (2.70 mL, 20.95 mmol) and methyl-3-bromobenzoate (4.95 g, 23.02 mmol) in 5:1 (v/v) toluene:t-BuOH (100 mL) was added. After stirring for 2 minutes, the vessel was sealed and the reaction mixture was heated at 120° C. for 16 hours. Upon cooling to room temperature, the reaction mixture was filtered through celite and the filtrate was concentrated. Elution through a flash column (silica gel 60, 230-400 mesh, 7:3 hexanes:EtOAc) followed by concentration gave the title compound as an oil (5.64 g, 97%).

Quelle