Methanol → Methyl 5-oxo-L-prolinate

To a solution of (2S)-5-pyrrolidone-2-carboxylic acid (75 g) in methanol (580 ml) was added dropwise thionyl chloride (150 ml) at 0° C. After the addition, the reaction mixture was allowed to warm to room temperature and stirred for two hours. The solvent was removed in vacuo, and the residue was diluted with a mixture of ethyl acetate (1 l), methanol (50 ml) and water (10 ml). To this mixture was added by portions potassium carbonate (50 g), and the mixture was stirred for two hours. The precipitate was filtered off, and the filtrate was dried over magnesium sulfate. Evaporation of the solvent gave methyl (2S)-5-pyrrolidone-2-carboxylate (82.5 g) as an oil.

1. additionAfter the addition
2. customThe solvent was removed in vacuo
3. additionthe residue was diluted with a mixture of ethyl acetate (1 l), methanol (50 ml) and water (10 ml)
4. additionTo this mixture was added by portions potassium carbonate (50 g)
5. stirringthe mixture was stirred for two hours
6. filtrationThe precipitate was filtered off
7. dry with materialthe filtrate was dried over magnesium sulfate
8. customEvaporation of the solvent

ORD record

ord-af71fb5d13554007a0bbe64b2d5ff069

Source dataset

uspto-grants-1992_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05102877