反应详情

Ethylmagnesium bromide (1.0 M in THF, 71.4 mL, 71.4 mmol) was added dropwise to a −78° C. solution of 2,4-dichloropyrimidine (10 g, 67.1 mmol) in THF (125 mL). After stirring for 1 h, saturated aqueous NH4Cl was added at −78° C. and the reaction was allowed to come to room temperature with stirring. Then, the reaction mixture was extracted with ethyl acetate. The organic layer was washed with saturated aqueous NaHCO3, then dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel eluting with ethyl acetate and hexanes to provide 2-chloro-4-ethylpyrimidine (5.031 g, 18.70 mmol, 27.9%) as a 53:47 regioisomeric mixture.

1. customto come to room temperature
2. stirringwith stirring
3. extractionThen, the reaction mixture was extracted with ethyl acetate
4. washThe organic layer was washed with saturated aqueous NaHCO3
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified by column chromatography on silica gel eluting with ethyl acetate and hexanes