反応 #65541

反応方程式

L-serine

sodium hydrogen carbonate

4-nitrobenzyloxycarbonyl chloride

4-nitrobenzyloxycarbonyl chloride

sodium hydrogen carbonate

→

methyl (2S)-3-hydroxy-2-[(4-nitrobenzyloxycarbonyl)amino]propionate

収率 24.2%

溶媒

water

diethyl ether

diethyl ether

反応条件

後処理

1. 1
   workup.STIRRINGAfter stirring for 3 hours
2. 2
   その他the aqueous layer was separated
3. 3
   洗浄washed with ethyl acetate
4. 4
   抽出the aqueous solution was extracted twice with ethyl acetate
5. 5
   乾燥dried over magnesium sulfate
6. 6
   その他evaporated
7. 7
   workup.ADDITIONTo the residue were added methanol (40 ml) and concentrated sulfuric acid (0.7 ml)
8. 8
   workup.STIRRINGthe solution was stirred at 50°-55° C. for 2.5 hours
9. 9
   workup.ADDITIONTo the mixture was added triethylamine (4.2 ml)
10. 10
    その他the mixture was evaporated in vacuo
11. 11
    workup.ADDITIONThe resulting residue was poured into a mixture of ethyl acetate and water
12. 12
    その他The organic layer was separated
13. 13
    洗浄washed twice with brine
14. 14
    乾燥dried over magnesium sulfate
15. 15
    その他evaporated
16. 16
    その他The residue was chromatographed on silica gel (300 ml)
17. 17
    洗浄eluted with a mixture of acetone and dichloromethane (8:92, V/V)

実験手順

To a stirred solution of L-serine (3.5 g) and sodium hydrogen carbonate (7.5 g) in water (46 ml) was added 4-nitrobenzyloxycarbonyl chloride (6.4 g) in diethyl ether (10 ml) at ambient temperature. After stirring for 2 hours, to the solution were added 4-nitrobenzyloxycarbonyl chloride (6.4 g) in diethyl ether (10 ml), and sodium hydrogen carbonate (3.6 g). After stirring for 3 hours, the aqueous layer was separated and washed with ethyl acetate. After adjusting the pH to 2 with concentrated hydrochloric acid, the aqueous solution was extracted twice with ethyl acetate, dried over magnesium sulfate and evaporated. To the residue were added methanol (40 ml) and concentrated sulfuric acid (0.7 ml), and the solution was stirred at 50°-55° C. for 2.5 hours. To the mixture was added triethylamine (4.2 ml) and the mixture was evaporated in vacuo. The resulting residue was poured into a mixture of ethyl acetate and water. The organic layer was separated, washed twice with brine, dried over magnesium sulfate and evaporated. The residue was chromatographed on silica gel (300 ml) and eluted with a mixture of acetone and dichloromethane (8:92, V/V) to give methyl (2S)-3-hydroxy-2-[(4-nitrobenzyloxycarbonyl)amino]propionate (2.14 g).

出典