L-Pyroglutamic Acid → tert-Butyl 5-oxo-L-prolinate

HRID 1737848Notes

Reaction equation

HRID 1737848 reaction equation
[NH:1]1[C:5](=[O:6])[CH2:4][CH2:3][C@H:2]1[C:7]([OH:9])=[O:8].C([O-])(O)=O.[Na+].C(O[C:19]([CH3:22])([CH3:21])[CH3:20])(=O)C>>[C:19]([O:8][C:7]([C@H:2]1[NH:1][C:5](=[O:6])[CH2:4][CH2:3]1)=[O:9])([CH3:22])([CH3:21])[CH3:20]

Participants

4

Reactant 3

HCID 7405L-Pyroglutamic AcidHCID 10908tert-Butyl acetateHCID 516892Sodium Bicarbonate

Product 1

HCID 10888648tert-Butyl 5-oxo-L-prolinate

Procedure

To a suspension of L-pyroglutamic acid (2.00 g, 15.49 mmol) in t-butyl acetate was added 70% HClO4 (0.46 mL, 17.04 mmol). The suspension was stirred at rt in a tightly closed flask overnight. The resulting solution was poured slowly into a sat. solution of NaHCO3 and extracted twice with EtOAc. The organic phase was dried over MgSO4 and concentrated to provide (S)-pyrrolidin-2-one-5-carboxylic acid t-butyl ester. (2.04 g, 85%) as a white solid 1H NMR (CDCl3) δ 1.48 (s, 9H), 2.16-2.48 (m, 4H), 4.14 (m, 1H), 5.97 (bs, 1H). MS calcd for C9H15NO3 +H 186, found 186.

Workup

  1. extractionextracted twice with EtOAc
  2. dry with materialThe organic phase was dried over MgSO4
  3. concentrationconcentrated

Sources & evidence

ORD record
ord-e9f5a86aa5a9482fb32b9236855572b5
Source dataset
uspto-grants-1999_10
Patent number
US05962487

Reaction notes

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