Hydrochloric Acid → 5-Carboxy-3-nitro-2phenylbenzenediazonium tetrafluoroborate

Participants

Reaction Steps

A hot solution of 3-amino-5-nitro-4-phenylbenzoic acid (39 g; prepared as in Example 1, step C) and potassium nitrite (15 g) in 1 N potassium hydroxide (260 ml) is added dropwise to a mixture of acetic acid (150 ml) and conc. hydrochloric acid (150 ml), while stirring vigorously at -2° to 2° C. After additional stirring at this temperature for about 10 minutes, 50% hydrofluoroboric acid (100 ml) is added during about 5 minutes, keeping the temperature below 5° C by external cooling. After additional stirring at about -10° C for 1 hour, the precipitated 5-carboxy-3-nitro-2-phenylbenzenediazonium tetrafluoroborate is collected by filtration, washed with icecold water (two portions of each 25 ml) and dried.

Provenance & Evidence