反应详情

温度

-10 °C

16.8 g of 2-ethoxy-6-bromopyridine were introduced into 220 ml of tetrahydrofuran at -75° C. 54.4 ml of n-butyllithium (1.6-molar solution in n-hexane) were added dropwise at this temperature. Stirring was continued for two hours at -75° C., and 7.6 g of N,N-dimethylacetamide were added dropwise at this temperature. The mixture was stirred for a further hour at -75° C. and then warmed to -10° C., and first approximately 170 ml of 20 percent strength aqueous ammonium chloride solution and then 200 ml of water were added dropwise at this temperature. The mixture was extracted 3 times using methyl tert-butyl ether. The combined organic phases were washed 3 times with water and subsequently dried over sodium sulfate. After the solvent had been stripped off, the residue which remained was chromatographed on silica gel using cyclohexane/methyl tert-butyl ether 8:1. This gave 5.5 g of 2-ethoxy-6-acetylpyridine as a colorless solid (m.p.: 36-37° C).

1. stirringThe mixture was stirred for a further hour at -75° C.
2. extractionThe mixture was extracted 3 times
3. washThe combined organic phases were washed 3 times with water
4. dry with materialsubsequently dried over sodium sulfate
5. customthe residue which remained was chromatographed on silica gel