反应详情

Under an argon atmosphere, a solution of 26.86 g (0.145 mole) of (rac)-3-cyclopentylamino-2-methyl-propanoic acid methyl ester in 25 mL of ethyl acetate was added over 5 minutes to a cooled (5 degrees) and stirring mixture of 28.13 g (0.145 mole) of 2,4-dichloro-5-nitro-pyrimidine, 48.72 g (0.58 mole) of sodium bicarbonate and 300 mL of ethyl acetate. The cooling bath was removed and the mixture stirred for 17 hours at room temperature. Activated charcoal was added and after stirring briefly, the mixture was filtered through a pad of Celite, washing the filter pad with ethyl acetate. The mixture was concentrated under reduced pressure to give 50.37 g of (rac)-3-[(2-chloro-5-nitro-pyrimidin-4-yl)-cyclopentyl-amino]-2-methyl-propanoic acid methyl ester (IV-1) as a thick oil, which contained a small portion of a regioisomer. This material was used directly in the next step without further purification.

1. temperaturea cooled (5 degrees)
2. customThe cooling bath was removed
3. stirringthe mixture stirred for 17 hours at room temperature
4. additionActivated charcoal was added
5. stirringafter stirring briefly
6. filtrationthe mixture was filtered through a pad of Celite
7. washwashing the filter pad with ethyl acetate
8. concentrationThe mixture was concentrated under reduced pressure