[Cl:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[F:9].[N+:10]([O-])([OH:12])=[O:11]>S(=O)(=O)(O)O>[Cl:1][C:2]1[C:3]([F:9])=[CH:4][C:5]([N+:10]([O-:12])=[O:11])=[C:6]([F:8])[CH:7]=11-Chloro-2,5-difluorobenzene (31.7 g, 0.21 mol) was dissolved in sulfuric acid (110 ml) at −40° C., then a solution of sulfuric acid (20 ml) and nitric acid (30 ml) was added dropwise. The mixture was stirred for 1 hr while temperature slowly raised to 20° C. The product was forced to crystallize by mixing the reaction mixture with ice-water (500 ml), the yellow crystals were filtered, washed with cold water and dried in fume hood overnight. (38.0 g). 1H NMR (CDCl3, 300 MHz) 7.46 (1H, dd, J=9.8, 9.9 Hz), 7.96 (1H, dd, J=7.9, 7.9 Hz) ppm.
Wird geladen…