Ethyl iodoacetate → Ethyl 2-(4-benzyloxycarbonyl-2-oxopiperazino)acetate

Temperatur

-10 °C

To a solution of 4-benyloxycarbonylpiperazin-2-one (M.W.=234.26, 2.34 g, 10 mmol) in anhydrous THF (150 mL) at −78° C. under argon was added lithium bis(trimethylsilyl) amide (1 M in THF, 12 mL, 12 mmol) dropwise. The mixture was stirred at −78° C. for 30 min Ethyl iodoacetate (M.W.−214, 2.14 g, 10 mmol) was added to the mixture at −78° C., stirred, warmed up to −10° C., and then kept in the freezer over night. The reaction was quenched by adding 1N HCl (60 mL) and extracted with EtOAc (200 mL+100 mL). The combined organic layers were washed with sat. NaCl three times, dried with MgSO4, and evaporated to give the crude title compound as a yellowish oil. Reversed-phase HPLC purification afforded the pure compound in 81% yield.

1. additionwas added to the mixture at −78° C.
2. waitkept in the freezer over night
3. customThe reaction was quenched
4. additionby adding 1N HCl (60 mL)
5. extractionextracted with EtOAc (200 mL+100 mL)
6. washThe combined organic layers were washed with sat. NaCl three times
7. dry with materialdried with MgSO4
8. customevaporated

ORD-Eintrag

ord-b4ae95728c25488888b6e5953e14300e

Quelldatensatz

uspto-grants-2001_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06211183B1