| abstract |
A process for the preparation of 4,4'-dinitrostilbene-2,2'-disulfonic acid and its salts, of the formula ##STR1## in which M is hydrogen or an alkali metal cation, by oxidation of 4-nitrotoluene-2-sulfonic acid in organic solvents, and also the reduction of the resulting acid or salt, without isolation, to give 4,4'-diamino- or (4-amino-4'-nitro)-stilbene-2,2'-disulfonic acid or salts thereof. |