2,2/-Benzidinedisulfonic acid

Technical Observations. In large scale operations, involving volumes of 4000 to 5000 liters, the crystallization of 2,2 -benzidinedisulfonic acid requires at least 3 days. In order to obtain rapid cooling, lead coils, through which cold water is circidated, are installed in the wooden vats. The sulfonic acid must be diazotized indirectly because of its insolubility. It is dissolved in the required amount of water and soda, the neutral solution is mixed with sodium nitrite, and the mixture is allowed to flow in a thin stream into hydrochloric or sulfuric acid. 

Benzidine, 3,3 -dimethoxy. See Dianisidine Benzidine, 2,2 -disulfo-. See 2,2 -Benzidinedisulfonic acid 2,2 -Benzidinedisulfonic acid CAS 117-61-3 EINECS/ELINCS 204-200-0 Synonyms Benzidine, 2,2 -disulfo- Benzidine-2,2 -disulfonic acid 6,6 -Bimetanilic acid (1,1 -Biphenyl)-2,2 -disulfonic acid, 4,4 -diamino- 2,2 -Biphenyldisulfonic acid, 4,4 -diamino-4,4 -Biphenyldisulfonic acid, 2,2 -diamino- 2,2 -Diamino-4,4 -biphenyldisulfonic acid 4,4 -Diamino-(1,1 -biphenyl)-2,2 -disulfonic acid 4,4 -Diaminobiphenyl-2,2 -disulfonic acid 4,4 -Diaminodiphenyl-2,2 -disulfonic acid 2,2 -Disulfobenzidine 2,2 -Disulfo-4,4 -diaminobiphenyl Empirical C12H12N2O6S2... 

Benzldine-2,2 -disulfonic acid. See 2,2 -Benzidinedisulfonic acid Benzidine hydrochloride. See Benzidine dihydrochloride... 

Biloxazol. See Bitertanol Bilt-Cote H Bitt-Cote H-5, Biit-Plates 145, Bilt-Plates 156. See Kaolin 6,6 -Bimetanilic acid. See 2,2 -Benzidinedisulfonic acid Bimethyl. See Ethane Bina QAT-43. See Lauramidopropyl acetamidodimonium chloride... 

Anthracene Anthranilic acid Anthraquinone Antimony pentachloride Benzaldehyde Benzidine dihydrochloride 2,2 -Benzidinedisulfonic acid Benzoguanamine Benzotrifluoride Benzoyl chloride N-Benzylamine N-Benzyl-N-ethyl-m-toluidine Bisphenol A Bromine 4-Bromochloro benzene Butyl acetoacetate n-Butylamine t-Butylamine Ceteareth-15 o-Chloroaniline p-Chloroaniline m-Chlorobenzoic acid o-Chlorobenzoic acid p-Chlorobenzoic acid m-Chlorobenzotrifluoride o-Chlorobenzotrifluoride p-Chlorobenzotrifluoride Chloroform 4-Chloro-2-nitroaniline 2-Chloronitrobenzene... 

Benzidinedisulfonic acid C12H12N2S 4,4 -Thiodianiline C12H12N4 HCI Basic orange 2 C12H12N4O5S2... 

Therefore, for curing the epoxy groups, special curing agents, such as, 4,4 -diaminodiphenylsulfone and 2,2 -benzidinedisulfonic acid, have been used. It has been demonstrated that 2,2 -benzidinedisulfonic acid, which bears sulfonic acid groups, can effectively reduce the loss of proton conductivity in the composite film [73]. 

Benzidinedisulfonic acid is so insoluble that it must be diazotized indirectly by dissolving it in soda or caustic solution, adding nitrite, and adding the solution to acid. 

Nitrobenzenesulfonic acid is prepared as described under metanilic acid. The reduction is different from similar reactions only in that it is carried out in dilute aqueous solution in three distinct steps, making it possible to obtain the benzidinedisulfonic acid with-a minimum amount of zinc dust and sodium hydroxide. 

Zhang, Y., and Litt, M. H. (1999). Polyimides based on naphthalene tetracarboxylic dianhydride and benzidinedisulfonic acid. ACS Polym. Preprints 40(2), 480. 

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