PURPLE CRYSTALLINE POWDER
4,4'-Diaminobiphenyl-2,2'-disulfonic acid hydrate is an important raw material and intermediate used in Organic Synthesis, Pharmaceuticals, Agrochemicals and Dyestuff. Benzidine-2,2' -disulfonic acid is used in the production of yellow and red azo dyes.
2,2'-Benzidinedisulfonic acid is made from the potassium or sodium salt of 3- nitrobenzenesulfonic acid by a gradual reduction using zinc dust and sodium hydroxide solution in a dilute aqueous solution. The product is subsequently rearranged using hydrochloric acid or dilute sulfuric acid. Electrochemical or catalytic reductions are also possible.
Leaflets or prisms or light purple powder.
Flash point data for 2,2'-Benzidinedisulfonic acid are not available; however, 2,2'-Benzidinedisulfonic acid is probably combustible.
Flammability and Explosibility
Non flammable
A severe eye irritant. When heated to decomposition it emitsvery toxic fumes of SOx and NOx.
