Reaktion #64239

ord-043998def5de4e08b6ecb68e0ad40b1f

Lösungsmittel

Reaktionsbedingungen

Temperatur
-60°CELSIUS
Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    Sonstigebeing kept below -15° C
  2. 2
    workup.WAITAfter 2 hours at -15° C.
  3. 3
    workup.STIRRINGthe mixture is subsequently stirred at room temperature for 15 hours
  4. 4
    Filtrationthe solid is filtered off
  5. 5
    Waschenrinsed with CH2Cl2
  6. 6
    Einengenthe filtrate is concentrated
  7. 7
    workup.ADDITIONthe residue is introduced into water
  8. 8
    Extraktionthe mixture is extracted twice with ethyl acetate
  9. 9
    Waschenthe combined ethyl acetate phases are washed with NaHCO3 solution and water
  10. 10
    Sonstigedried
  11. 11
    Einengenconcentrated

Vorschrift

2.3 g (0.023 mol) of N-methylpiperidine are added to 5.0 g of t-butoxycarbonyl-L-valine (0.023 mol), dissolved in 50 ml of CH2Cl2, at -20° C. 3.2 g (0.023 mol) of isobutyl chloroformate are then rapidly added dropwise at -20° C., the mixture is subsequently stirred at the same temperature for 10 minutes and cooled to -60° C. and 3.5 g (0.023 mol) of 4-methoxy-1-phenylethylamine are allowed to run in, the temperature being kept below -15° C. After 2 hours at -15° C., the mixture is subsequently stirred at room temperature for 15 hours, the solid is filtered off and rinsed with CH2Cl2, the filtrate is concentrated, the residue is introduced into water, the mixture is extracted twice with ethyl acetate and the combined ethyl acetate phases are washed with NaHCO3 solution and water, dried and concentrated. 17.5 g (85% of theory) of N-(t-butoxycarbonyl)-L-valine 4-methoxy-1-phenylethylamide of melting point 126°-127° C. are obtained.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US05411987uspto-grants-1995_05