Methanol → (S)-1-isopropyl-5-oxopyrrolidine-2-carboxylic acid

Methyl 1-(1-methylethyl)-5-oxo-prolinate (0.152 g, 0.82 mmol) was dissolved in water (3 ml) and methanol (0.5 ml) and treated with 2M aqueous sodium hydroxide (0.682 ml, 1.36 mmol). The mixture was stirred for ˜4 hrs at room temperature and then washed with dichloromethane. The aqueous layer was evaporated and the residue treated with an excess of 1M hydrogen chloride in ether (˜5 ml). The mixture was evaporated once more and the residue was triturated with dichloromethane. The solid material was discarded and the combined dichloromethane fractions were evaporated to give 1-(1-methylethyl)-5-oxo-proline (0.060 g) as a yellow oil which crystallized on standing.

1. washwashed with dichloromethane
2. customThe aqueous layer was evaporated
3. additionthe residue treated with an excess of 1M hydrogen chloride in ether (˜5 ml)
4. customThe mixture was evaporated once more
5. customthe residue was triturated with dichloromethane
6. customthe combined dichloromethane fractions were evaporated

ORD record

ord-ea906a4419bc41eb9c2c4ff7a3dd1224

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08048907B2