Реакция #7381

Уравнение реакции

Thionyl chloride

D-glutamic acid

potassium hydrogen carbonate

benzyl chloroformate

ethyl acetate

→

title compound

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

Растворители

methanol

water

Условия реакции

Обработка

1. 1
   Температураthe mixture subsequently heated
2. 2
   Температураunder reflux for 16 h
3. 3
   ТемператураOn cooling
4. 4
   Концентрированиеthe mixture was concentrated under reduced pressure
5. 5
   Другоеthe residue azeotroped with toluene
6. 6
   Другоеto give a white solid
7. 7
   workup.ADDITIONwas added
8. 8
   ПромывкаThe separated organic phase was washed with water
9. 9
   Сушкаdried (over magnesium sulphate)
10. 10
    Концентрированиеconcentrated under reduced pressure
11. 11
    Другоеto provide a yellow oil
12. 12
    ДругоеThis oil was purified
13. 13
    Промывкаflash column chromatography (silica, eluting with cyclohexane:ethyl acetate 2:1)

Методика

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.

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