Reaktion #10217

Reaktionsgleichung

(Z)-4-Oxo-5-aza-2-undecendioic acid

acetic anhydride

phenothiazine

HCl

water

→

desired product

N-Succinimidyl 6-Maleimidohexanoate

Lösungsmittel

THF

Triethylamine

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeequipped with an overhead stirrer
2. 2
   Temperaturthe mixture was heated
3. 3
   Temperaturto reflux
4. 4
   TemperaturAfter a total of 4 hours of reflux
5. 5
   Temperaturthe dark mixture was cooled to <60° C.
6. 6
   workup.STIRRINGThe mixture was stirred 3 hours at room temperature
7. 7
   Filtrationwas filtered through a Celite 545 pad
8. 8
   Sonstigeto remove solids
9. 9
   ExtraktionThe filtrate was extracted with 4×500 ml of chloroform
10. 10
    Trocknenthe combined extracts were dried over sodium sulfate
11. 11
    workup.ADDITIONAfter adding 15 mg of phenothiazine
12. 12
    Sonstigepolymerization
13. 13
    Sonstigethe solvent was removed under reduced pressure
14. 14
    SonstigeThe 6-maleimidohexanoic acid was recrystallized from hexane/chloroform (2/1)
15. 15
    Sonstigeto give typical
16. 16
    Sonstigeyields of 76–83 g (55–60%) with a melting point of 81–85° C

Vorschrift

(Z)-4-Oxo-5-aza-2-undecendioic acid, 150.0 g (0.654 moles), acetic anhydride, 68 ml (73.5 g, 0.721 moles), and phenothiazine, 500 mg, were added to a 2 liter three-neck round bottom flask equipped with an overhead stirrer. Triethylamine, 91 ml (0.653 moles), and 600 ml of THF were added and the mixture was heated to reflux while stirring. After a total of 4 hours of reflux, the dark mixture was cooled to <60° C. and poured into a solution of 250 ml of 12 N HCl in 3 liters of water. The mixture was stirred 3 hours at room temperature and then was filtered through a Celite 545 pad to remove solids. The filtrate was extracted with 4×500 ml of chloroform and the combined extracts were dried over sodium sulfate. After adding 15 mg of phenothiazine to prevent polymerization, the solvent was removed under reduced pressure. The 6-maleimidohexanoic acid was recrystallized from hexane/chloroform (2/1) to give typical yields of 76–83 g (55–60%) with a melting point of 81–85° C. Analysis on a NMR spectrometer was consistent with the desired product.

Quelle