Ammonium Chloride → HCID 66582880, compound

Participants

Reaction Conditions

Reaction Steps

A 150-mL round-bottomed flask was charged with 4-benzyl 1-tert-butyl 2-oxo-1,4-piperazinedicarboxylate (1.41 g, 4.22 mmol) and THF (5 mL). 1-Propynylmagnesium bromide (0.5 M in THF, 20.0 mL, 10.0 mmol, Sigma-Aldrich, St. Louis, Mo.) was added at 0° C. slowly. The mixture was stirred at 0° C. for 2 h. Saturated aqueous NH4Cl (40 mL) was added and the aqueous phase was extracted with EtOAc (200 mL, then 2×100 mL). The combined organic phases were dried over sodium sulfate, filtered and concentrated in vacuo. The crude product was purified by column chromatography (50 g of silica, 0 to 50% EtOAc in hexanes) to afford benzyl (2-((tert-butoxycarbonyl)amino)ethyl)(2-oxo-3-pentyn-1-yl)carbamate (1.55 g) as a clear oil.

Provenance & Evidence