反应详情

温度

140 °C

1328 g (4.34 mol) of dimethyl 2,6-dichloro-isonicotinoyl-malonate are dissolved in a mixture of 3.45 l of dimethyl sulphoxide and 156.2 g (8.68 mol) of water. The reaction mixture is heated to 140° C. and stirred at this temperature for 30 minutes. After this, the reaction mixture is cooled to 10° C. and then added to 8.4 l of ice-water. The mixture is extracted twice with a total of 3.6 l of dichloromethane and the combined organic phases are washed once with 1.5 l of saturated, aqueous sodium hydrogen carbonate solution. After drying over sodium sulphate, the organic phase is concentrated under reduced pressure. The residue which remains is distilled under reduced pressure. In this manner 506.0 g (60% of theory) of 4-acetyl-2,6-dichloropyridine of boiling point 98° C. at 0.5 mbar are obtained. ##STR36##

1. temperatureAfter this, the reaction mixture is cooled to 10° C.
2. extractionThe mixture is extracted twice with a total of 3.6 l of dichloromethane
3. washthe combined organic phases are washed once with 1.5 l of saturated, aqueous sodium hydrogen carbonate solution
4. dry with materialAfter drying over sodium sulphate
5. concentrationthe organic phase is concentrated under reduced pressure
6. distillationThe residue which remains is distilled under reduced pressure