Reaction #172405

Reaction equation

water hydrochloric acid

3-bromopyridin-2(1H)-one

1-fluoro-2,5-dimethyl-4-nitrobenzene

potassium carbonate

→

3-Bromo-1-(2,6-dimethyl-4-nitrophenyl)pyridin-2(1H)-one

Solvents

dimethyl sulphoxide

dimethyl sulphoxide

Conditions

Workup

1. 1
   TemperatureAfter cooling
2. 2
   ExtractionThe mixture is extracted with ethyl acetate
3. 3
   Otherthe phases are separated
4. 4
   Extractionthe aqueous phase is once more extracted with ethyl acetate
5. 5
   WashThe combined organic phases are then washed with water
6. 6
   OtherThe phases are separated
7. 7
   Dryingthe organic phase is dried over sodium sulphate
8. 8
   ConcentrationAfter concentration under reduced pressure
9. 9
   Otherthe residue is purified by chromatography on silica gel (dichloromethane
10. 10
    Otherthe solvents are removed
11. 11
    Otherthe residue is triturated with diethyl ether

Procedure

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.

Source