Dimethylformamide → (2S)-2-benzyloxycarbonylamino-3-[[4-(3-nitrophenyl)piperazin-1-yl]carbonylamino]propanoic Acid Methyl Ester

Temperature

25 °C

To a solution of the compound of Reference Example 13 (300 mg) and ethyldiisopropylamine (0.656 ml) in dichloromethane (10 ml) is added chloroformic acid p-nitrophenyl ester (273 mg), and the mixture is stirred at 25° C. for 6 hours. To the reaction solution are added a solution of (2S)-3-amino-2-(benzyloxycarbonylamino)propanoic acid methyl ester hydrochloride (709 mg) and ethyldiisopropylamine (0.65 ml) in dimethylformamide (20 ml), and the mixture is stirred at 60° C. overnight. The reaction solution is diluted with ethyl acetate, and then the mixture is washed successively with 10% aqueous citric acid solution, saturated aqueous sodium hydrogen carbonate solution, and saturated brine, dried over magnesium sulfate, and the solvent is evaporated under reduced pressure. The residue is purified by silica gel column chromatography (eluent: gradient, 0% to 100% ethyl acetate/hexane) to give the title compound (120 mg).

1. stirringthe mixture is stirred at 60° C. overnight
2. washthe mixture is washed successively with 10% aqueous citric acid solution, saturated aqueous sodium hydrogen carbonate solution, and saturated brine
3. dry with materialdried over magnesium sulfate
4. customthe solvent is evaporated under reduced pressure
5. customThe residue is purified by silica gel column chromatography (eluent: gradient, 0% to 100% ethyl acetate/hexane)

ORD record

ord-7c41607a6f0b49038136f0efa8933284

Source dataset

uspto-grants-2007_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07176199B2