反应 #2122482

反应方程式

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

triethylamine

4-dimethylaminopyridine DMAP

ethyl chloroformate

→

crude product

carbonic acid 3-(2,5-dimethyl-phenyl)-8-methoxy-2-oxo-1-oxa-8-aza-spiro[4.5]dec-3-en-4-yl ester ethyl ester

溶剂

THF

THF

反应条件

后处理

1. 1
   workup.WAITleft
2. 2
   其他Then the solvent was removed under vacuum
3. 3
   workup.ADDITIONEthyl acetate was added to the residue
4. 4
   其他the precipitation
5. 5
   过滤was filtered off
6. 6
   浓缩The filtrate was concentrated under vacuum

实验过程

To a solution of 3-(2,5-dimethyl-phenyl)-4-hydroxy-8-methoxy-1-oxa-8-aza-spiro[4.5]dec-3-en-2-one (120 mg, 0.40 mmol), triethylamine (0.08 ml, 60 mg, 0.60 mmol) and 4-dimethylaminopyridine DMAP (2 mg, 0.02 mmol) in 4 ml THF at 0° C. was added a solution of ethyl chloroformate (0.05 ml, 52 mg, 0.50 mmol) dissolved in 1 ml THF dropwise. The suspension was kept at 0° C. for 30 minutes under argon and left stirring at room temperature overnight. Then the solvent was removed under vacuum. Ethyl acetate was added to the residue and the precipitation was filtered off. The filtrate was concentrated under vacuum to give the crude product, which was purified by column chromatography on silica gel (ethyl acetate/cyclohexane 1:9). Yield: 111 mg of carbonic acid 3-(2,5-dimethylphenyl)-8-methoxy-2-oxo-1-oxa-8-aza-spiro[4.5]dec-3-en-4-yl ester ethyl ester (title compound P1.1) as a light yellow gum.

来源