Reacción #50035

Ecuación de reacción

methanol

sulfuryl chloride

L-pyroglutamic acid

→

pyroglutamic methyl ester

Rendimiento 91.0%

Disolventes

DMF

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturato warm slowly
2. 2
   OtroThe methanol was removed under vacuum
3. 3
   workup.DISSOLUTIONthe residue was dissolved in ethyl acetate (400 mL)
4. 4
   workup.ADDITIONWater (~10 mL) was added
5. 5
   workup.ADDITIONfollowed by the addition of sodium carbonate until basic
6. 6
   OtroThe organic layer was decanted
7. 7
   Lavadothe slurry was washed with ethyl acetate (4×15 mL)
8. 8
   Secadodried over magnesium sulfate
9. 9
   OtroRemoval of the solvent

Procedimiento

To methanol (30.0 mL), cooled to -10° to -15° C., was slowly added sulfuryl chloride (11.0 mL, 178 mmol), DMF (0.133 mL) and L-pyroglutamic acid (L=(S) configuration, 10.0 g, 77.5 mmol, Sigma Chemical Co.). The stirred mixture was allowed to warm slowly and then stirred at room temperature for 36 hours. The methanol was removed under vacuum, and the residue was dissolved in ethyl acetate (400 mL). Water (~10 mL) was added, followed by the addition of sodium carbonate until basic. The organic layer was decanted, the slurry was washed with ethyl acetate (4×15 mL), and the organics were then combined and dried over magnesium sulfate. Removal of the solvent gave crude pyroglutamic methyl ester (10.04 g, 91%). NMR and MS analysis indicated >95% purity.

Fuente