The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Nucleophilic substitution of aromatic chlorine in diazonium ions by bromide ions》. Authors are Lamm, Bo.The article about the compound:3-Bromo-4-chloronitrobenzenecas:16588-26-4,SMILESS:BrC1=C(C=CC(=C1)[N+](=O)[O-])Cl).Related Products of 16588-26-4. Through the article, more information about this compound (cas:16588-26-4) is conveyed.
To determine why a Cl atom in a suitably substituted diazonium ion should not be replaced by a Br- ion, the reaction of 2-chloro-5-nitrobenzenediazonium ion in an HBr-AcOH-H2O medium at 25° was studied. It was found that some of the aromatic Cl is “”frozen in”” and no quant. conversion of aromatic Cl to Br can occur; the reverse reactions are considerably more rapid than the forward ones, so that a small amount of Cl- ions generated in the exchange reaction produces an equilibrium containing comparable amounts of each, despite the large excess of HBr; and the equilibrium is continually being disturbed by the side-reactions, which cannot be suppressed by increasing the Br- ion concentration
In addition to the literature in the link below, there is a lot of literature about this compound(3-Bromo-4-chloronitrobenzene)Related Products of 16588-26-4, illustrating the importance and wide applicability of this compound(16588-26-4).
Reference:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts