4-Chloro-3,5-dinitrobenzenesulfonic acid is produced by a process based on the sulfonation and nitration of chlorobenzene that uses 2 mol/mol of potassium nitrate, in place of the 1 mol/mol employed in the production of 4- chloro-3-nitrobenzenesulfonic acid. The product is isolated from the quenched reaction mixture as the potassium salt, after addition of potassium chloride.
