反応 #7381

反応方程式

Thionyl chloride

D-glutamic acid

potassium hydrogen carbonate

benzyl chloroformate

ethyl acetate

→

title compound

Dimethyl (2R)-2-{[(benzyloxy)carbonyl]amino}pentanedioate

溶媒

methanol

water

反応条件

後処理

1. 1
   温度the mixture subsequently heated
2. 2
   温度under reflux for 16 h
3. 3
   温度On cooling
4. 4
   濃縮the mixture was concentrated under reduced pressure
5. 5
   その他the residue azeotroped with toluene
6. 6
   その他to give a white solid
7. 7
   workup.ADDITIONwas added
8. 8
   洗浄The separated organic phase was washed with water
9. 9
   乾燥dried (over magnesium sulphate)
10. 10
    濃縮concentrated under reduced pressure
11. 11
    その他to provide a yellow oil
12. 12
    その他This oil was purified
13. 13
    洗浄flash column chromatography (silica, eluting with cyclohexane:ethyl acetate 2:1)

実験手順

Thionyl chloride (30 ml) was added to a cooled solution of D-glutamic acid (33.2 g) in methanol (250 ml) and the mixture subsequently heated under reflux for 16 h. On cooling, the mixture was concentrated under reduced pressure and the residue azeotroped with toluene to give a white solid. This was stirred with ethyl acetate, water and potassium hydrogen carbonate at 0° C. while benzyl chloroformate (30 ml) was added. The mixture was warmed to room temperature and stirred for 5 h. The separated organic phase was washed with water, dried (over magnesium sulphate) and concentrated under reduced pressure to provide a yellow oil. This oil was purified using flash column chromatography (silica, eluting with cyclohexane:ethyl acetate 2:1) to give the title compound (22.45 g) as an oil.

出典