反应 #1178405

反应方程式

(Z)-4-oxo-5-azaundec-2-enedioic acid

acetic anhydride

phenothiazine

HCl

water

→

desired product

N-Succinimidyl 6-Maleimidohexanoate

溶剂

THF

Triethylamine

反应条件

后处理

1. 1
   其他equipped with an overhead stirrer
2. 2
   温度the mixture was heated
3. 3
   温度to reflux
4. 4
   温度After a total of 4 hours of reflux
5. 5
   workup.STIRRINGThe mixture was stirred 3 hours at room temperature
6. 6
   过滤was filtered through a filtration pad (Celite 545, J. T. Baker, Jackson, Tenn.)
7. 7
   其他to remove solids
8. 8
   萃取The filtrate was extracted with 4×500 ml of chloroform
9. 9
   干燥the combined extracts were dried over sodium sulfate
10. 10
    workup.ADDITIONAfter adding 15 mg of phenothiazine
11. 11
    其他polymerization
12. 12
    其他the solvent was removed under reduced pressure
13. 13
    其他The 6-maleimidohexanoic acid was recrystallized from 2:1 hexane
14. 14
    其他chloroform to give typical
15. 15
    其他yields of 76-83 g (55-60%) with a melting point of 81-85° C

实验过程

(Z)-4-oxo-5-azaundec-2-enedioic 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 about 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 filtration pad (Celite 545, J. T. Baker, Jackson, Tenn.) 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 2:1 hexane:chloroform 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: 1H NMR (CDCl3) maleimide protons 6.55 (s, 2H), methylene adjacent to nitrogen 3.40 (t, 2H), methylene adjacent to carbonyl 2.30 (t, 2H), and remaining methylenes 1.05-1.85 (m, 6H).

来源