Ethanol → ethyl (2R)-5-oxopyrrolidine-2-carboxylate
Reaction equation
[CH2:1]([OH:3])[CH3:2].[NH:4]1[C:8](=[O:9])[CH2:7][CH2:6][C@@H:5]1[C:10](O)=[O:11].C[Si](Cl)(C)C.C(=O)(O)[O-].[Na+]>C1(C)C=CC=CC=1.ClCCl>[CH2:1]([O:3][C:10]([C@H:5]1[CH2:6][CH2:7][C:8](=[O:9])[NH:4]1)=[O:11])[CH3:2]Participants
Conditions
- Temperature
- 30 °C
Procedure
To a flask containing anhydrous ethanol and D-pyroglutamic acid at ambient temperature (˜23° C.) was slowly added trimethylsilyl chloride while maintaining a reaction temperature NMT 30° C. After stirring at ambient temperature for a period of time, the reaction solution was concentrated under reduced pressure to give a yellow oil. The product was dissolved in toluene and concentrated under reduced pressure to give a yellow oil. The crude product was dissolved in dichloromethane and stirred with the slow addition of aqueous saturated sodium bicarbonate solution until a pH of 7-8 was reached. The organic layer was isolated, and the aqueous layer was extracted further with dichloromethane. The combined organic layers were dried over sodium sulfate, filtered and concentrated under reduced pressure to give product, (R)-5-oxo-pyrrolidine-2-carboxylic acid ethyl ester, as a yellow oil.
Workup
- concentrationthe reaction solution was concentrated under reduced pressure
- customto give a yellow oil
- concentrationconcentrated under reduced pressure
- customto give a yellow oil
- customThe organic layer was isolated
- extractionthe aqueous layer was extracted further with dichloromethane
- dry with materialThe combined organic layers were dried over sodium sulfate
- filtrationfiltered
- concentrationconcentrated under reduced pressure
Sources & evidence
- ORD record
- ord-fecc04cab3fb4503a234755abac8d1df
- Source dataset
- uspto-grants-2015_02
- Patent number
- US08962863B2
Reaction notes
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