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

HRID 884385Notes

Reaction equation

HRID 884385 reaction equation
[NH:1]1[C:5](=[O:6])[CH2:4][CH2:3][C@H:2]1[C:7]([OH:9])=[O:8].Cl(O)(=O)(=O)=O.C([O-])(O)=O.[Na+].C(O[C:24]([CH3:27])([CH3:26])[CH3:25])(=O)C>>[C:24]([O:8][C:7]([C@@H:2]1[CH2:3][CH2:4][C:5](=[O:6])[NH:1]1)=[O:9])([CH3:27])([CH3:26])[CH3:25]

Participants

5

Reactant 4

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

Product 1

HCID 10888648tert-Butyl 5-oxo-L-prolinateYield 58%

Procedure

30.0 g of L-pyroglutamic acid 133 (232 mmol) was suspended in 500 ml of tert-butyl acetate and added with 12 ml of 60% perchloric acid. After stirring for 15 h at RT, the resulting clear solution was cooled to 0° C. and adjusted to a pH value of 4-5 by adding 30.0 g of solid NaHCO3. After removing the solid by filtration, the filtrate was concentrated to dryness, thereby obtaining 25.4 g (136 mmol, 58%) of the tert-butyl ester 206 as a white solid that was reacted without further purification. An analytical sample was obtained by column chromatography over silica gel (eluant: EE).

Workup

  1. temperaturethe resulting clear solution was cooled to 0° C.
  2. customAfter removing the solid
  3. filtrationby filtration
  4. concentrationthe filtrate was concentrated to dryness

Sources & evidence

ORD record
ord-ff935afa6e9b4d6f87ad2fa927a632d1
Source dataset
uspto-grants-2012_08
Patent number
US08242105B2

Reaction notes

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