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Disodium 4,4′-dinitrostilbene-2,2′-disulfonate is an organic compound with the formula (O2NC6H3(SO3Na)CH)2 This salt is a common precursor to a variety of textile dyes.
Preparation and reactions
In the laboratory disodium 4,4′-dinitrostilbene-2,2′-disulfonate is obtained by sulfonation of 4-nitrotoluene giving the intermediate product, which is further oxidized with sodium hypochlorite yielding 4,4′-dinitrostilbene-2,2′-disulfonic acid disodium salt.
The compound is useful because it couples with aniline derivatives to give azo dyes. Commercially important dyes derived from this compound include Direct Red 76, Direct Brown 78, and Direct Orange 40.
References
Disodium 4,4'-dinitrostilbene-2,2'-disulfonate Wikipedia(Text) CC BY-SA