Ammonia → 4-Nitro-4'-amino-stilbene-2,2'-disulphonic acid

Reaktionsgleichung

[Na][Na].[N+:3]([C:6]1[CH:7]=[C:8]([S:27]([OH:30])(=[O:29])=[O:28])[C:9]([CH:12]=[CH:13][C:14]2[C:15]([S:23]([OH:26])(=[O:25])=[O:24])=[CH:16][C:17]([N+:20]([O-:22])=[O:21])=[CH:18][CH:19]=2)=[CH:10][CH:11]=1)([O-])=O.[Na].N>>[N+:20]([C:17]1[CH:16]=[C:15]([S:23]([OH:26])(=[O:24])=[O:25])[C:14]([CH:13]=[CH:12][C:9]2[C:8]([S:27]([OH:30])(=[O:29])=[O:28])=[CH:7][C:6]([NH2:3])=[CH:11][CH:10]=2)=[CH:19][CH:18]=1)([O-:22])=[O:21]

Komponenten

Edukt 4

HCID 222Ammonia

HCID 194595-Nitro-2-[2-(4-nitro-2-sulfophenyl)ethenyl]benzenesulfonic acid

HCID 141233Disodium

HCID 5360545Sodium

Produkt 1

HCID 670714-Nitro-4'-amino-stilbene-2,2'-disulphonic acid

Versuchsvorschrift

An aqueous solution of the disodium salt of 4,4'-dinitro-stilbene-2,2'-disulphonic acid is treated with an equivalent amount, relative to the nitro group to be reduced, of sodium bisulphide solution at 75°-85° C., ammonia being added. The course of the reaction can be followed by known analytical methods. When the partial reduction has ended, the 4-nitro-4'-amino-stilbene-2,2'-disulphonic acid formed is isolated as the disodium salt or as an inner salt. The amount of 4,4'-diamino-stilbene-2,2'-disulphonic acid contained as an impurity is less than 1% and the residual content of 4,4'-dinitro-stilbene-2,2'-disulphonic acid is less than 0.1%. 4-Nitro-4'-aminostilbene-2,2'-disulphonic acid is a known intermediate product for dyestuffs.