Реакция #88339

Уравнение реакции

iso-butyl chloroformate

diazomethane

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

triethylamine

→

desired product

Выход 82.0%

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

Выход 82.0%

Растворители

ether

THF

Условия реакции

Обработка

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

Методика

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).

Источник