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

HRID 1630041Notes

Reaction equation

HRID 1630041 reaction equation
Cl(O)(=O)(=O)=O.[O:6]=[C:7]1[NH:11][C@H:10]([C:12]([OH:14])=[O:13])[CH2:9][CH2:8]1.C(=O)(O)[O-].[Na+].C(O[C:24]([CH3:27])([CH3:26])[CH3:25])(=O)C>>[O:6]=[C:7]1[NH:11][C@H:10]([C:12]([O:14][C:24]([CH3:27])([CH3:26])[CH3:25])=[O:13])[CH2:9][CH2:8]1

Participants

5

Reactant 4

HCID 7405L-Pyroglutamic AcidHCID 10908tert-Butyl acetateHCID 24247Perchloric AcidHCID 516892Sodium Bicarbonate

Product 1

HCID 10888648tert-Butyl 5-oxo-L-prolinateYield 75.5%

Procedure

Step (a) Aqueous perchloric acid (70%, 5 mL) was added to a solution of (S)-5-oxopyrrolidine-2-carboxylic acid (20 g, 154.9 mmol) in tert-butyl acetate (260 mL) at ambient temperature. The mixture was stirred at ambient temperature for 18 hrs in a 500 mL round bottom flask sealed with a rubber septum and then poured carefully into sat. sodium bicarbonate (200 mL). The mixture was extracted with ethyl acetate (2×200 mL) and the combined extract was dried over anhydrous sodium sulfate and concentrated in vacuo. The crude product solidified under high vacuum. The solid was treated with a 10:1 hexanes/diethyl ether mixture. The solids were collect by filtration and dried to give (S)-tert-butyl 5-oxopyrrolidine-2-carboxylate (21.65 g, 116.9 mmol, 75.5%), clean as a white solid.

Workup

  1. customsealed with a rubber septum
  2. extractionThe mixture was extracted with ethyl acetate (2×200 mL)
  3. extractionthe combined extract
  4. dry with materialwas dried over anhydrous sodium sulfate
  5. concentrationconcentrated in vacuo
  6. additionThe solid was treated with a 10:1 hexanes/diethyl ether mixture
  7. filtrationThe solids were collect by filtration
  8. customdried

Sources & evidence

ORD record
ord-2bbaf5f3257d452096c83358fd9c71a8
Source dataset
uspto-grants-2014_07
Patent number
US08791102B2

Reaction notes

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