تفاعل #7381

معادلة التفاعل

Thionyl chloride

D-glutamic acid

potassium hydrogen carbonate

benzyl chloroformate

ethyl acetate

→

title compound

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

المذيبات

methanol

water

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةthe mixture subsequently heated
2. 2
   درجة الحرارةunder reflux for 16 h
3. 3
   درجة الحرارةOn cooling
4. 4
   تركيزthe mixture was concentrated under reduced pressure
5. 5
   أخرىthe residue azeotroped with toluene
6. 6
   أخرىto give a white solid
7. 7
   workup.ADDITIONwas added
8. 8
   غسيلThe separated organic phase was washed with water
9. 9
   تجفيفdried (over magnesium sulphate)
10. 10
    تركيزconcentrated under reduced pressure
11. 11
    أخرىto provide a yellow oil
12. 12
    أخرىThis oil was purified
13. 13
    غسيلflash column chromatography (silica, eluting with cyclohexane:ethyl acetate 2:1)

الإجراء التجريبي

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.

المصدر