Sodium Hydroxide → L-Proline, 1-ethyl-5-oxo-

Temperature

0 °C

Ethyl 1-ethyl-5-oxoprolinate (1.33 g, 7.18 mmol) was dissolved in ethanol (10 ml) and cooled to 0° C. in an ice bath. To this was added 12.5M aqueous sodium hydroxide solution (1.72 ml, 21.53 mmol) and the mixture was stirred for ˜4 hours at 0° C. The ethanol was evaporated under vacuum and the aqueous residue was acidified with 2N aqueous hydrogen chloride to pH1. The volume of the aqueous phase was reduced to ˜3 ml under vacuum and then extracted with a 3:1 mixture of chloroform and isopropanol using a phase separator. The combined organic layers were concentrated to a pale yellow oil which on drying in vacuo crystallized to give 1-ethyl-5-oxoproline as a white solid (1.12 g).

1. customThe ethanol was evaporated under vacuum
2. extractionextracted with a 3:1 mixture of chloroform and isopropanol using a phase separator
3. concentrationThe combined organic layers were concentrated to a pale yellow oil which
4. customon drying in vacuo
5. customcrystallized

ORD record

ord-6213c73d62f64a3f85d00cb922231de7

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08048907B2