Reaktion #1153559

Reaktionsgleichung

N6-Carbobenzyloxy-L-lysine

maleic acid

HCl

→

Asp

Lösungsmittel

NaOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe solution was refluxed for 24 hr
2. 2
   Temperaturto cool
3. 3
   Temperaturchilled
4. 4
   FiltrationThe mixture was filtered
5. 5
   Sonstigeto remove the unreacted maleic acid which
6. 6
   Waschenwas washed with water (15 mL)
7. 7
   Sonstigeevaporated
8. 8
   workup.DISSOLUTIONThe residue was dissolved in 4% ammonium formate (120 mL)
9. 9
   Sonstigedegassed briefly
10. 10
    workup.ADDITION10% Pd/C (600 mg) was added
11. 11
    Temperaturthe mixture was refluxed under Ar
12. 12
    FiltrationThe mixture was filtered through celite
13. 13
    Sonstigethe filtrate evaporated
14. 14
    workup.DISSOLUTIONThe residue was dissolved in a solution of sodium hydroxide (1.3 g) and sodium carbonate (8.7 g) in dd H2O (40 mL)
15. 15
    workup.ADDITIONThis solution is added to the oxirane-derivatized resin (40 mL bed volume)
16. 16
    Sonstigeprepared
17. 17
    workup.STIRRINGThe mixture was stirred at 60°
18. 18
    workup.STIRRINGwith mechanical stirring for 4 hr
19. 19
    workup.WAITat ambient for 16 hr
20. 20
    FiltrationThe resin was collected by filtration
21. 21
    Waschenwashed with ddH2O (6×100 mL), 10% HOAc (6×100 mL), and ddH2O (6×100 mL) or until the pH
22. 22
    Sonstigedried in preparation for metal loading

Vorschrift

N6-Carbobenzyloxy-L-lysine (6.15 g) and excess maleic acid (17.6 g) were dissolved in 2 M NaOH (35 mL). The solution was refluxed for 24 hr and allowed to cool to ambient. The pH was adjusted to 3 with 6 M HCl and chilled. The mixture was filtered to remove the unreacted maleic acid which was washed with water (15 mL). The filtrate and washings were combined and evaporated. The residue was dissolved in 4% ammonium formate (120 mL) and degassed briefly. 10% Pd/C (600 mg) was added and the mixture was refluxed under Ar with stirring for 5 hr. The mixture was filtered through celite and the filtrate evaporated. The residue was dissolved in a solution of sodium hydroxide (1.3 g) and sodium carbonate (8.7 g) in dd H2O (40 mL). The final pH was adjusted to 11. This solution is added to the oxirane-derivatized resin (40 mL bed volume) prepared as described in Example 1. The mixture was stirred at 60° with mechanical stirring for 4 hr and at ambient for 16 hr. The resin was collected by filtration, washed with ddH2O (6×100 mL), 10% HOAc (6×100 mL), and ddH2O (6×100 mL) or until the pH reached about 6 by litmus paper test. The C-Linked CM-Asp chelating resin was suction dried in preparation for metal loading.

Quelle