تفاعل #88329

معادلة التفاعل

iso-butyl chloroformate

diazomethane

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

triethylamine

→

desired product

المردود 82.3%

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

المردود 82.3%

المذيبات

ether

THF

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

To a 0° C. solution of 2-(S)-tert-butoxycarbonylamino-3-(4-nitrophenyl)-propionic acid (1.20 g, 4.0 mmol) in THF (20 mL) is added dropwise triethylamine (0.61 mL, 4.4 mmol) followed by iso-butyl chloroformate (0.57 mL, 4.4 mmol). The reaction mixture is stirred at 0° C. for 20 minutes then filtered. The filtrate is treated with an ether solution of diazomethane (˜16 mmol) at 0° C. The reaction mixture is stirred at room temperature for 3 hours and concentrated. The residue is dissolved in EtOAc and washed successively with water and brine, dried (Na2SO4), filtered and concentrated in vacuo. The resulting residue is 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