Tetrafluoroboric acid → 2,3-Dichloro-4,5-difluorobenzenediazonium tetrafluoroborate

Reaction equation

[Cl:1][C:2]1[C:8]([Cl:9])=[C:7]([F:10])[C:6]([F:11])=[CH:5][C:3]=1[NH2:4].[N:12]([O-])=O.[Na+].[F:16][B-:17]([F:20])([F:19])[F:18].[H+]>O>[F:16][B-:17]([F:20])([F:19])[F:18].[Cl:1][C:2]1[C:8]([Cl:9])=[C:7]([F:10])[C:6]([F:11])=[CH:5][C:3]=1[N+:4]#[N:12]

Participants

Procedure

To a suspension of 2,3-dichloro-4,5-difluoroaniline (0.88 g) in 42% fluoroboric acid (10 ml) with stirring vigorously was added sodium nitrite (0.43 g) in water (1 ml) at -15° to 0° C. for 14 minutes. After stirred for 3 hours at the same temperature, the resulting precipitate was collected by filtration, washed with 42% fluoroboric acid and then with ether to give the title compound (0.66 g) as white powdery crystals, mp 211° C. (decompd.).