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

Participants

Reaction Conditions

Reaction Steps

225.5 g (2.3 mol) of 100% strength sulphuric acid were added to 257.0 g (2.76 mol) of aniline in 460 ml of ortho oil. The suspension obtained was heated at 200° C. for 2.5 hours in a 1.3 1 enamel autoclave. After cooling, the mixture was filtered off with suction and the filter residue was dried. The 475.6 g of solid contained 80.7% of p-sulphanilic acid in addition to unchanged anilinium hydrogensulphate, based on the excess sulphuric acid employed. Aniline-2,4-disulphonic acid was not formed.

Provenance & Evidence