反应详情

温度

120 °C

150 g (750 mmol) of 3-bromopyridin-2(1H)-one (O. S. Tee, M. Pavent, J. Am. Chem. Soc. 1982, 104, 4142-4146.) and 207 g (1.50 mol) of potassium carbonate are dissolved in 2.9 l of dimethyl sulphoxide and heated to 120° C. At this temperature, a solution of 317 g (750 mmol) of 1-fluoro-2,5-dimethyl-4-nitrobenzene in 700 ml of dimethyl sulphoxide is added dropwise over a period of 60 min, and the mixture is stirred at 120° C. for 3.5 h. After cooling, the reaction solution is stirred into a water/hydrochloric acid mixture. The mixture is extracted with ethyl acetate, the phases are separated and the aqueous phase is once more extracted with ethyl acetate. The combined organic phases are then washed with water. The phases are separated, and the organic phase is dried over sodium sulphate. After concentration under reduced pressure, the residue is purified by chromatography on silica gel (dichloromethane, then ethyl acetate/dichloromethane 1:20). The product-containing fractions are combined, the solvents are removed and the residue is triturated with diethyl ether. This gives 112 g (46% of theory) of the desired compound.

1. temperatureAfter cooling
2. extractionThe mixture is extracted with ethyl acetate
3. customthe phases are separated
4. extractionthe aqueous phase is once more extracted with ethyl acetate
5. washThe combined organic phases are then washed with water
6. customThe phases are separated
7. dry with materialthe organic phase is dried over sodium sulphate
8. concentrationAfter concentration under reduced pressure
9. customthe residue is purified by chromatography on silica gel (dichloromethane
10. customthe solvents are removed
11. customthe residue is triturated with diethyl ether