반응 #709030

반응 방정식

2-chloro-3-nitropyridine

(S)-alanine ethyl ester hydrochloride

triethylamine

→

title compound

수율 0.1%

(S)-N-(3-Nitro-2-pyridinyl)alanine hydrochloride

수율 0.1%

용매

ethanol

반응 조건

후처리

1. 1
   온도was heated
2. 2
   온도at reflux for 4.5 hours, during which time a dark yellow solution
3. 3
   기타formed
4. 4
   온도refluxed for an additional 2 hours
5. 5
   기타The solvents were evaporated under reduced pressure
6. 6
   기타the resulting solid was triturated in ethyl acetate
7. 7
   여과filtered
8. 8
   세척rinsed with additional ethyl acetate
9. 9
   세척washed three times with water
10. 10
    건조dried over sodium sulfate
11. 11
    여과filtered
12. 12
    기타evaporated to an oil
13. 13
    세척The oil was eluted through 600 g of silica gel
14. 14
    기타evaporated to an oil
15. 15
    workup.DISSOLUTIONA 3.5-g portion of the oil was dissolved in isopropyl alcohol
16. 16
    기타The mixture was evaporated
17. 17
    workup.DISSOLUTIONredissolved in acetonitrile
18. 18
    workup.ADDITIONAddition of isopropyl ether
19. 19
    기타to precipitate
20. 20
    여과The solid was collected by filtration and its mother liquor
21. 21
    기타was evaporated
22. 22
    기타the residue was triturated in ethereal hydrogen chloride
23. 23
    기타A yellow solid formed which
24. 24
    여과was collected by filtration
25. 25
    기타more solid formed in the mothor liquor
26. 26
    여과This solid was collected by filtration
27. 27
    세척rinsed with diethyl ether
28. 28
    기타dried under high vacuum

실험 절차

A suspension of 2-chloro-3-nitropyridine (68.6 g, 0.434 mole), (S)-alanine ethyl ester hydrochloride (100 g, 0.651 mole) and triethylamine (103.7 g, 1.03 mole) in 95% ethanol was heated at reflux for 4.5 hours, during which time a dark yellow solution formed. The reaction mixture was stirred at room temperature overnight and then refluxed for an additional 2 hours. The solvents were evaporated under reduced pressure, and the resulting solid was triturated in ethyl acetate, filtered, and rinsed with additional ethyl acetate. The filtrate and washings were combined and washed three times with water, dried over sodium sulfate, filtered, and evaporated to an oil weighing 107 g (quantitative yield). The oil was eluted through 600 g of silica gel, using ethyl acetate as the eluent, and evaporated to an oil. A 3.5-g portion of the oil was dissolved in isopropyl alcohol and acidified with ethereal hydrogen chloride. The mixture was evaporated and redissolved in acetonitrile. Addition of isopropyl ether caused a solid to precipitate. The solid was collected by filtration and its mother liquor was evaporated and the residue was triturated in ethereal hydrogen chloride. A yellow solid formed which was collected by filtration. Upon standing, more solid formed in the mothor liquor. This solid was collected by filtration, rinsed with diethyl ether and dried under high vacuum to give 0.14 g of title compound, mp >260° C. (darkens 178°-185° C.).

출처