Reaktion #434958

Reaktionsgleichung

di-tert-butylazodicarboxylate

tert-butyl 1-cyclohexyl-2-hydroxyethylcarbamate

5-bromo-1-(2,6-difluorobenzyl)-6-methylpyrimidine-2,4(1H,3H)-dione

triphenylphosphine

→

compound 4b

Ausbeute 95.4%

5-bromo-3-[2(R)-tert-butoxycarbonylamino-2-cyclohexylethyl]-1-[2,6-difluorobenzyl]-6-methyl-pyrimidine-2,4(1 H,3H)-dione

Ausbeute 95.4%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigevolatiles were evaporated
2. 2
   SonstigeThe residue was partitioned between saturated NaHCO3/H2O and EtOAc
3. 3
   TrocknenThe organic layer was dried (sodium sulfate)
4. 4
   Sonstigeevaporated
5. 5
   Sonstigepurified by flash chromatography (silica, 25% EtOAc/hexanes)

Vorschrift

A solution of tert-butyl 1-cyclohexyl-2-hydroxyethylcarbamate 4a (638 mg, 2.62 mmol) in THF (10 mL) was treated with 5-bromo-1-(2,6-difluorobenzyl)-6-methylpyrimidine-2,4(1H,3H)-dione 1d.1 (869 mg, 2.62 mmol) and triphenylphosphine (1.03 g, 3.93 mmol) at ambient temperature, then di-tert-butylazodicarboxylate (906 mg, 3.93 mmol) was introduced. The reaction mixture was stirred at ambient temperature for 16 hours and volatiles were evaporated. The residue was partitioned between saturated NaHCO3/H2O and EtOAc. The organic layer was dried (sodium sulfate), evaporated, and purified by flash chromatography (silica, 25% EtOAc/hexanes) to give compound 4b (1.39 g, 95.4% ). MS (CI) m/z 456.1, 458.1 (MH+-Boc).

Quelle