反应详情

温度

70 °C

6-chloro-2-cyano-3-nitropyridine (9.50 g, 51.76 mmol) is taken up in 150 mL of 90% H2SO4 solution. The reaction mixture is stirred for 4 h at 70° C., cooled and slowly added dropwise to ice water. The precipitate formed is filtered off, washed with water and dried. The aqueous filtrate is extracted 6× with DCM. The organic phases are combined, dried on Na2SO4, filtered off and concentrated by rotary evaporation. The residue is mixed with the precipitate, dried overnight at 50° C. in the drying cupboard and 6-chloro-3-nitro-pyridine-2-carboxylic acid amide (HPLC-MS: tRet.=0.43 min; MS (M+H)+=202) is obtained.

1. temperaturecooled
2. customThe precipitate formed
3. filtrationis filtered off
4. washwashed with water
5. customdried
6. extractionThe aqueous filtrate is extracted 6× with DCM
7. customdried on Na2SO4
8. filtrationfiltered off
9. concentrationconcentrated by rotary evaporation
10. additionThe residue is mixed with the precipitate
11. customdried overnight at 50° C. in the drying cupboard