Hydrochloric Acid → 2,4-Dichloro-5-nitropyridine
Reaktionsgleichung
[Cl:1][C:2]1[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][N:5]=[C:4](N)[CH:3]=1.N([O-])=O.[Na+].[ClH:16]>>[Cl:16][C:4]1[CH:3]=[C:2]([Cl:1])[C:7]([N+:8]([O-:10])=[O:9])=[CH:6][N:5]=1Komponenten
4
Versuchsvorschrift
To 4-chloro-5-nitropyridine-2-amine (Method 92, 4.40 g, 21.0 mmol) in concentrated HCl (70 ml) was added sodium nitrite (4.36 g, 63.1 mmol) potion wise at 0-5° C. After 1 hour at 0-5° C., the reaction was warmed to room temperature and stirred for 50 hours. Ice (100 g) was added and the mixture was extracted with ether (2×50 ml) and dried over sodium sulfate. The solvent was removed under reduced pressure and the resulted residue was purified by column chromatography (hexane-DCM=1:5) to give the title compound as a white solid (1.47 g, 33%). 1H NMR (400 MHz) 9.18 (s, 1H), 8.22 (s, 1H).