反应详情

A solution of 1.99 g (0.010 mole) of (rac)-3-cyclopentylamino-2-methyl-propanoic acid ethyl ester in 25 mL of water was added dropwise to a solution of 1.94 g (0.010 mole) of 2,4-dichloro-5-nitro-pyrimidine in 25 mL of ethyl ether. At 0 degrees, 2.0 g (0.020 mole) of potassium bicarbonate was added. The mixture was stirred at ambient temperature for 3 hours. The layers were then separated, and the aqueous layer extracted twice with 30 mL of ether. The combined organic layers were dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. Purification by silica gel chromatography, eluting with hexanes-ethyl acetate (100:0-80:20) gave 3.0 g of (rac)-3-[(2-chloro-5-nitro-pyrimidin-4-yl)-cyclopentyl-amino]-butanoic acid ethyl ester (IV-1)

1. customThe layers were then separated
2. extractionthe aqueous layer extracted twice with 30 mL of ether
3. dry with materialThe combined organic layers were dried over anhydrous magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customPurification by silica gel chromatography
7. washeluting with hexanes-ethyl acetate (100:0-80:20)