反应详情

To a solution of 3-oxopiperazine-1-carboxylic acid benzyl ester (4.68 g, 20 mmol) in 20 mL of DMF at) 0° C. is added sodium hydride (60%, 880 mg, 22 mmol). The suspension is stirred at ambient temperature for one t-butyl bromoacetate (4.68 g, 24 mmol) is added. The resulting mixture is stirred at ambient temperature overnight. After dilution with ethyl acetate (200 mL), the mixture is washed with brine (3×50 mL). The crude residue obtained from concentration of the organic phase is chromatographied on silica gel (30% ethyl acetate/Hexane) to give 5.57 g (80%) of 4-tert-butoxycarbonylmethyl-3-oxopiperazine-1-carboxylic acid benzyl ester as a white solid.

1. additionis added
2. washAfter dilution with ethyl acetate (200 mL), the mixture is washed with brine (3×50 mL)
3. customThe crude residue obtained from concentration of the organic phase