反応 #425870

反応方程式

4-piperidone ethylene ketal

methyl-4-bromobenzoate

X-Phos

cesium carbonate

→

title compound

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

溶媒

toluene

t-BuOH

t-BuOH

toluene

反応条件

後処理

1. 1
   その他A thick-walled glass reaction vessel
2. 2
   その他The stirred contents were purged with nitrogen
3. 3
   その他the vessel was sealed
4. 4
   温度Upon cooling to room temperature
5. 5
   ろ過the reaction mixture was filtered through celite
6. 6
   濃縮the filtrate was concentrated
7. 7
   洗浄Elution through a flash column (silica gel 60, 230-400 mesh, 3:2 hexanes:EtOAc)

実験手順

Procedure adopted from Tetrahedron Lett., 2007, 48, 2519. A thick-walled glass reaction vessel was charged with palladium(II)acetate (157 mg, 0.698 mmol), X-Phos (332 mg, 0.698 mmol, 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl), cesium carbonate (4.55 g, 13.96 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 (1.80 mL, 13.96 mmol) and methyl-4-bromobenzoate (3.30 g, 15.36 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 18 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, 3:2 hexanes:EtOAc) gave the title compound as an off-white, crystalline solid (3.20 g, 83%).

出典