反应详情

温度

60 °C

Methyl (2R)-2-(cyclopentylamino)butanoate 1k (2.50 g, 13.50 mmol) and sodium bicarbonate (4.54 g, 54 mmol) were dissolved in 100 mL of cyclohexane, stirred for 30 minutes followed by the addition of 2,4-dichloro-5-nitro-pyrimidine (2.88 g, 14.84 mmol), heated to 60° C. and stirred for another 12 hours. The reaction mixture was filtered, washed with dichloromethane (50 mL), and the filtrate was concentrated under reduced pressure, the resulting residue was recrystallized by 150 mL of the mixture solvent of ethyl acetate and n-hexane (V/V=1:4) to obtain the title compound methyl (2R)-2-[(2-chloro-5-nitro-pyrimidin-4-yl)-(1-cyclopentyl)amino]butanoate 1m (3.36 g, yield: 72.6%) as a light yellow solid.

1. stirringstirred for another 12 hours
2. filtrationThe reaction mixture was filtered
3. washwashed with dichloromethane (50 mL)
4. concentrationthe filtrate was concentrated under reduced pressure
5. customthe resulting residue was recrystallized by 150 mL of the mixture solvent of ethyl acetate and n-hexane (V/V=1:4)