反応 #2122483

反応方程式

(2,4,5-trimethyl-phenyl)acetic acid methyl ester

4-hydroxy-1-methoxy-piperidine-4-carboxylic acid ethyl ester

potassium tert-butoxide

→

4-Hydroxy-8-methoxy-3-(2,4,5-trimethyl-phenyl)-1-oxa-8-aza-spiro[4.5]dec-3-en-2-one

溶媒

THF

THF

反応条件

後処理

1. 1
   その他The suspension obtained
2. 2
   温度refluxed under argon for one hour
3. 3
   温度After cooling to room temperature
4. 4
   濃縮the reaction mixture was concentrated
5. 5
   workup.ADDITIONwater was added
6. 6
   抽出The aqueous layer was extracted with dichloromethane
7. 7
   洗浄the combined organic layers were then washed with brine
8. 8
   乾燥dried over sodium sulfate
9. 9
   ろ過After filtration and concentration under vacuum
10. 10
    その他the residue was purified by column chromatography (silica gel, ethyl acetate 100%)

実験手順

To a solution of (2,4,5-trimethyl-phenyl)acetic acid methyl ester (0.6 g, 3.12 mmol) and 4-hydroxy-1-methoxy-piperidine-4-carboxylic acid ethyl ester (0.76 g, 3.74 mmol) in 7 ml anhydrous THF was added a 1 M solution of potassium tert-butoxide (6.9 ml, 8.87 mmol) in THF at room temperature. The suspension obtained was first stirred at room temperature for one hour, and then refluxed under argon for one hour. After cooling to room temperature, the reaction mixture was concentrated, water was added and the mixture acidified with little HCl (37%). The aqueous layer was extracted with dichloromethane, and the combined organic layers were then washed with brine and dried over sodium sulfate. After filtration and concentration under vacuum, the residue was purified by column chromatography (silica gel, ethyl acetate 100%). Yield: 280 mg of 4-hydroxy-8-methoxy-3-(2,4,5-trimethyl-phenyl)-1-oxa-8-aza-spiro[4.5]dec-3-en-2-one (title compound P2.2) as a white solid, mp 199-204° C.

出典