تفاعل #88339

معادلة التفاعل

iso-butyl chloroformate

diazomethane

2-(S)-tert-butoxycarbonylamino-3-(4-nitrophenyl)-propionic acid

triethylamine

→

desired product

المردود 82.0%

(S)-[3-diazo-1-(4-nitrobenzyl)-2-oxo-propyl]-carbamic acid tert-butyl ester

المردود 82.0%

المذيبات

ether

THF

ظروف التفاعل

المعالجة

1. 1
   ترشيحfiltered
2. 2
   workup.STIRRINGThe reaction mixture was stirred at room temperature for 3 hours
3. 3
   تركيزthen concentrated in vacuo
4. 4
   workup.DISSOLUTIONThe resulting residue was dissolved in EtOAc
5. 5
   غسيلwashed successively with water and brine
6. 6
   تجفيفdried (Na2SO4)
7. 7
   ترشيحfiltered
8. 8
   تركيزconcentrated
9. 9
   أخرىThe residue was purified over silica (hexane/EtOAc 2:1)

الإجراء التجريبي

To a 0° C. solution of 2-(S)-tert-butoxycarbonylamino-3-(4-nitrophenyl)-propionic acid, 1, (1.20 g, 4.0 mmol) in THF (20 mL) was added dropwise triethylamine (0.61 mL, 4.4 mmol) followed by iso-butyl chloroformate (0.57 mL, 4.4 mmol). The reaction mixture was stirred at 0° C. for 20 minutes and filtered. The filtrate was treated with an ether solution of diazomethane (˜16 mmol) at 0° C. The reaction mixture was stirred at room temperature for 3 hours then concentrated in vacuo. The resulting residue was dissolved in EtOAc and washed successively with water and brine, dried (Na2SO4), filtered and concentrated. The residue was purified over silica (hexane/EtOAc 2:1) to afford 1.1 g (82% yield) of the desired product as a slightly yellow solid. 1H NMR (300 MHz, CDCl3) δ 8.16 (d, J=8.7 Hz, 2H), 7.39 (d, J=8.7 Hz, 2H), 5.39 (s, 1H), 5.16 (d, J=6.3 Hz, 1H), 4.49 (s, 1H), 3.25 (dd, J=13.8 and 6.6, 1H), 3.06 (dd, J=13.5 and 6.9 Hz, 1H), 1.41 (s, 9H).

المصدر