反应详情

温度

-78 °C

N-butyl lithium (1.6 mol solution in hexane, 19.4 ml) is added dropwise at 0° C., under a nitrogen atmosphere, to a solution of diisopropylamine (4.4 ml) in tetrahydrofuran (100 ml), and the mixture is stirred for 20 minutes. The solution is cooled to -78° C. and then 5 g of 4,5-dichloro-6-ethylpyrimidine in solution in 10 ml of tetrahydrofuran are added dropwise. The mixture is stirred at -78° C. for one hour and then brought to room temperature over a period of 2 hours. After the addition of water (200 ml), the mixture is extracted with ethyl acetate and the organic phase is dried over sodium sulfate and concentrated. Chromatography on silica gel (eluant: ethyl acetate/hexane 1:10) yields 3.8 g (71% of the theoretical yield) of 4,5-dichloro-6-isopropylpyrimidine in the form of a yellow oil.

1. stirringThe mixture is stirred at -78° C. for one hour
2. waitbrought to room temperature over a period of 2 hours
3. extractionthe mixture is extracted with ethyl acetate
4. dry with materialthe organic phase is dried over sodium sulfate
5. concentrationconcentrated
6. customChromatography on silica gel (eluant: ethyl acetate/hexane 1:10) yields 3.8 g (71% of the