Ethanol → Ethyl 5-oxo-L-prolinate

HRID 884374Notes

Reaction equation

HRID 884374 reaction equation
[NH:1]1[C:5](=[O:6])[CH2:4][CH2:3][C@H:2]1[C:7]([OH:9])=[O:8].O=S(Cl)Cl.[CH2:14](O)[CH3:15]>>[CH2:14]([O:8][C:7]([C@@H:2]1[CH2:3][CH2:4][C:5](=[O:6])[NH:1]1)=[O:9])[CH3:15]

Participants

4

Reactant 3

HCID 702EthanolHCID 7405L-Pyroglutamic AcidHCID 24386Thionyl Chloride

Product 1

HCID 2724446Ethyl 5-oxo-L-prolinateYield 99%

Procedure

A suspension of 30.0 g of L-pyroglutamic acid 133 (232 mmol) in 100 ml of anhydrous ethanol was slowly added with 20 ml of SOCl2 (274 mmol, 1.2 eq.) at 0° C. and subsequently stirred for 15 h, and the batch was thawed to room temperature to form a clear solution. For work-up, all volatile components were completely removed under vacuum, the remaining residue was subsequently taken up in 500 ml of ethyl acetate and successively stirred over K2CO3 and MgSO4, each time removing the drying agent by suction. Filtration over a small amount of silica gel and solvent removal under vacuum afforded 36.0 g (230 mmol, 99%) of ester 203 in the form of a slightly yellowish, viscous oil.

Workup

  1. customwas thawed to room temperature
  2. customto form a clear solution
  3. customFor work-up, all volatile components were completely removed under vacuum
  4. stirringsuccessively stirred over K2CO3 and MgSO4
  5. customeach time removing the drying agent by suction
  6. filtrationFiltration
  7. customover a small amount of silica gel and solvent removal under vacuum

Sources & evidence

ORD record
ord-940f666d0a6241089324fb38c08035f4
Source dataset
uspto-grants-2012_08
Patent number
US08242105B2

Reaction notes

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