反应详情

(z)-4-oxo-5-aza-undec-2-endioic acid, (160 g; 0.698 moles), zinc chloride, 280 g (2.05 moles), and phenothiazine, 0.15 g were added to a two liter round bottom flask fitted with an overhead stirrer, condenser, thermocouple, addition funnel, an inert gas inlet, and heating mantle. Chloroform (CHCl3), 320 mL was added to the 2 liter reaction flask, and stirring of the mixture was started. Triethylamine (480 mL; 348 g, 3.44 moles (TEA)) was added over one hour. Chlorotrimethyl silane (600 mL; 510 g, 4.69 moles) was then added over two hours. The reaction was brought to reflux and was refluxed overnight (˜16 hours). The reaction was cooled and added to a mixture of CHCl3 (500 mL), water (1.0 liters), ice (300 g), and 12 N hydrochloric acid (240 mL) in a 20 liter container over 15 minutes. After 15 minutes of stirring, the aqueous layer was tested to make sure the pH was less than 5. The organic layer was separated, and the aqueous layer was extracted three times with CHCl3 (700 mL) each extraction. The organic layers were combined and evaporated on a rotary evaporator. The residue was then placed in a 20 liter container. A solution of sodium bicarbonate (192 g) in water (2.4 liters) was added to the residue. The bicarbonate solution was stirred until the solids were dissolved. The bicarbonate solution was treated with a solution of hydrochloric acid, (26 liters of 1.1 N) over 5 minutes to a pH of below 2. The acidified mixture was then extracted with two portions of CHCl3, (1.2 liters and 0.8 liters) each extraction. The combined extracts were dried over sodium sulfate and evaporated. The residue was recrystallized from toluene and hexane. The crystalline product was then isolated by filtration and dried which produced 85.6 g of white N-(6-oxo-6-hydroxyhexyl)maleimide (Mal-EACA; Compound 2). Analysis on an NMR spectrometer was consistent with the desired product: 1H NMR (CDCl3, 400 MHz) δ 6.72 (s, 2H; maleimide protons), 3.52 (t, 2H, J=7.2 Hz; methylene next to maleimide), 2.35 (t, 2H, J=7.4; methylene next to carbonyl), 1.69-1.57 (m, 4H; methylenes adjacent to central methylene), and 1.39-1.30 (m, 2H; the central methylene). The product had a DSC (differential scanning calorimator) melting point peak at 89.9° C.

1. customfitted with an overhead stirrer, condenser
2. additionthermocouple, addition funnel, an inert gas inlet
3. temperatureheating mantle
4. temperatureto reflux
5. temperaturewas refluxed overnight (˜16 hours)
6. temperatureThe reaction was cooled
7. stirringAfter 15 minutes of stirring
8. customThe organic layer was separated
9. extractionthe aqueous layer was extracted three times with CHCl3 (700 mL)
10. extractioneach extraction
11. customevaporated on a rotary evaporator
12. additionA solution of sodium bicarbonate (192 g) in water (2.4 liters) was added to the residue
13. stirringThe bicarbonate solution was stirred until the solids
14. dissolutionwere dissolved
15. additionThe bicarbonate solution was treated with a solution of hydrochloric acid, (26 liters of 1.1 N) over 5 minutes to a pH of below 2
16. extractionThe acidified mixture was then extracted with two portions of CHCl3, (1.2 liters and 0.8 liters)
17. extractioneach extraction
18. dry with materialThe combined extracts were dried over sodium sulfate
19. customevaporated
20. customThe residue was recrystallized from toluene and hexane
21. customThe crystalline product was then isolated by filtration
22. customdried which