Reaktion #50026

Reaktionsgleichung

NaHCO3

L-pyroglutamic acid

methanol

H2SO4

→

(S)-Pyroglutamic Acid Methyl Ester

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   TemperaturThe reaction mixture was cooled to room temperature
3. 3
   workup.STIRRINGthe mixture was stirred for an additional 16 hr
4. 4
   TrocknenThe mixture was dried by addition of 314 g of Na2SO4
5. 5
   workup.STIRRINGwith stirring for 1 hr
6. 6
   Filtrationthe mixture was filtered
7. 7
   Sonstigethe solvent was evaporated under vacuum
8. 8
   Sonstigeto yield a pale yellow oil
9. 9
   Filtrationa small amount of unreacted acid was filtered off
10. 10
    SonstigeThe THF was removed under vacuum
11. 11
    Trocknenthe residual oil was dried by azeotropic distillation with toluene

Vorschrift

A 500 g sample of L-pyroglutamic acid was added to 2.8 L of anhydrous methanol, 28 mL of H2SO4 was added, and the mixture was stirred for 4 hr at 60° C. The reaction mixture was cooled to room temperature, 262 g of NaHCO3 was added, and the mixture was stirred for an additional 16 hr. The mixture was dried by addition of 314 g of Na2SO4 with stirring for 1 hr, then the mixture was filtered and the solvent was evaporated under vacuum to yield a pale yellow oil. The oil was dissolved in THF, and a small amount of unreacted acid was filtered off. The THF was removed under vacuum, and the residual oil was dried by azeotropic distillation with toluene.

Quelle