Реакция #88329

Уравнение реакции

iso-butyl chloroformate

diazomethane

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

triethylamine

→

desired product

Выход 82.3%

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

Выход 82.3%

Растворители

ether

THF

Условия реакции

Обработка

1. 1
   Фильтрацияthen filtered
2. 2
   workup.STIRRINGThe reaction mixture is stirred at room temperature for 3 hours
3. 3
   Концентрированиеconcentrated
4. 4
   workup.DISSOLUTIONThe residue is dissolved in EtOAc
5. 5
   Промывкаwashed successively with water and brine
6. 6
   Сушкаdried (Na2SO4)
7. 7
   Фильтрацияfiltered
8. 8
   Концентрированиеconcentrated in vacuo
9. 9
   ДругоеThe resulting residue is purified over silica (hexane/EtOAc 2:1)

Методика

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).

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