Sulfuric Acid → 4-Amino-1,3-benzenedisulfonic acid

Participants

Reaction Steps

186.2 g (2 mols) of aniline are initially introduced into 500 ml of 1,2-dichlorobenzene and 208.3 g (2.04 mols) of 96% strength sulphuric acid are added dropwise. The mixture is heated for 8 hours at the boil under a water separator, during which period distillate passes over at a rate of 700 ml per hour, cooled and filtered with suction. After it has been dried, the precipitate weighs 338.5 g and contains 86.1% of p-sulphanilic acid (84.2% of the theoretical yield) and 11.2% of aniline-2,4-disulphonic acid (7.5%, relative to aniline).

Provenance & Evidence