3-Nitrobenzolsulfonsure

VerwendenOrganic synthesis. The sodium salt is a protective antireduction agent.

Verwenden3-Nitrobenzenesulfonic acid is used primarily as a mild oxidizing agent or as a precursor for colorant intermediates. In the former case it is used in processing certain anthraquinone intermediates (e.g., amination of anthraquinone-1-sulfonic acid to give 1- aminoanthraquinone) or as a dye-printing auxiliary to obtain resist effects with, for example, vat dyes. Reduction of 3-nitrobenzenesulfonic acid (usually as a liquor) to the important metanilic acid is achieved with iron or by catalytic hydrogenation. The alternative reduction with zinc and alkali or with sodium amalgam yields hydrazobenzene-3,3'-disulfonic acid, which rearranges to benzidine-2,2' - disulfonic acid [117-61-3] on treatment with acid.