[Cl:1][C:2]1[CH:3]=[C:4]([OH:8])[CH:5]=[N:6][CH:7]=1.[N+:9]([O-])([OH:11])=[O:10]>S(=O)(=O)(O)O>[Cl:1][C:2]1[CH:3]=[C:4]([OH:8])[C:5]([N+:9]([O-:11])=[O:10])=[N:6][CH:7]=1With ice cooling, 30 g of 5-chloropyridin-3-ol (232 mmol, 1 equivalent) were dissolved in 228 ml of concentrated sulphuric acid, and, at 0° C., 24 ml of concentrated nitric acid were added slowly. The reaction was warmed to RT and stirred overnight. The mixture was stirred into an ice/water mixture and stirred for another 30 min. The solid was filtered off, washed with cold water and air-dried. This gave 33 g (82% of theory) of the title compound, which were used without further purification for the next reaction.
Wird geladen…