Benzene-1,3-disulfonic acid

Resorcinol Benzene + H2S04 - m.benzene disulfonic acid + NaOH... 

In a similar way resorcinol is made by fusion of m-benzene disulfonic acid ... 

Chelators that were not at all effective in rodent studies include monosodium glutamate, Tiron (4,5-dihydroxy-1,3-benzene-disulfonic acid), DMSA (2,3-dimercaptosuccinic acid), succinic acid, malic acid, CaNa2CTDA (cyclohexanediaminetetraacetic acid), and THPC, a cyclic derivative of EDTA (Kostial et al. 1979 Llobet et al. 1992b Ortega et al. 1989). 

The additives that go into the nickel bath are almost always proprietary carrier portions may include the sodium salts of benzene disulfonic acid, naphthalene 1,5-disulfonic acid, saccharin, and aHyl sulfonic acid. Generally, these compounds are characterized by a —S02 group. Brightener—leveler... 

With other metals, in particular with aluminium and its alloys, the ennobling mechanism is not clear-cut. Recent work by Yan et al. [60] carried out with PPy doped with electroinactive 1,3-benzene-disulfonic acid and electroactive sodium 4,5-dihydroxy-l,3-benzene-disulfonate and using a two-compartment cell similar to that of Rammelt et al. [64] seems to prove that the anodic protection model cannot be applied to the aluminum surface. Although the recharging of PPy by O2 was demonstrated, they found that a small area of exposed aluminium (AA 2024-T3) simulating a defect in a coating and immersed in dilute Harrison s solution (0.35 wt% (NH4)2S04 + 0.05 wt% NaCl in water) did not... 

Diazo coupling involves the N exocyclic atom of the diazonium salt, which acts as an electrophilic center. The diazonium salts of thiazoles couple with a-naphthol (605). 2-nitroresorcinol (606), pyrocatechol (607-609), 2.6-dihydroxy 4-methyl-5-cyanopyridine (610). and other heteroaromatic compounds (404. 611) (Scheme 188). The rates of coupling between 2-diazothicizolium salts and 2-naphthol-3.6-disulfonic acid were measured spectrophotometrically and found to be slower than that of 2-diazopyridinium salts but faster than that of benzene diazonium salts (561 i. The bis-diazonium salt of bis(2-amino-4-methylthiazole) couples with /3-naphthol to give 333 (Scheme 189) (612). The products obtained from the diazo coupling are usuallv highly colored (234. 338. 339. 613-616). 

Sulfonation. Benzene is converted iato benzenesulfonic acid [98-11-3] C H SO, upon reaction with fuming sulfuric acid (oleum) or chlorosulfonic acid. y -Benzenedisulfonic acid [98-48-6] CgHgS20, is prepared by reaction of benzene-sulfonic acid with oleum for 8 h at 85°C. Often under these conditions, appreciable quantities ofT -benzenedisulfonic acid [31375-02-7] are produced. 1,3,5-Benzenetrisulfonic acid [617-99-2] C H S Og, is produced by heating the disulfonic acid with oleum at 230°C (21). 

In the reaction of the strongly electrophilic 4-nitrobenzenediazonium ion with 2-naphthol-6,8-disulfonic acid, which yields a sterically hindered o-complex, Roller and Zollinger (1970) actually observed the rapid formation of a 7T-complex spec-trophotometrically at low pH. The concentration of the 7T-complex decreases slowly and at the same rate as that of the formation of the azo product. H NMR data indicate that the 7t-complex is not localized. All 7T-electrons of the benzene and the naphthalene system are involved in the complex formation to a similar degree, in... 

NF 279,88 -(carbonylbis(itnino-4,l-phenylenecarbonylimino-4,l-phenylenecarbonylimino)) bis(l,3,5-naphthalenetrisulphonic acid) NF 449,4,4, 4,/,4 "-(carbonylbis(imino-5,l, 3-benzenetriylbis(carbonyl imino)))tetrakis-benzene-l,3-disulfonic acid PPADS, pyridoxalphos-phate-6-azophenyl-2, 4 -disulfonic acid tetrasodium salt TNP-ATP,... 

Can be prepd by fusing benzene-met a-disulfonic acid with NaOH, and dissolving the melt in water. After acidifying the soln with HC1, the resorcinol is extracted with a volatile solvent and the solvent evaporated, purification can be achieved by distillation... 

Several metals, including iron, copper and tin, can fog emulsions. Emulsions can be partly stabilized by sequestering these metallic species with suitable ligands. Catechol derivatives are reported to be helpful in preventing fog from this source. Examples include 1,2-dihydroxy-benzene-4-sulfonic acid (sodium salt) and l,2-dihydroxybenzene-3,5-disulfonic acid (disodium salt).37... 

Permethylated tosylated a-cyclodextrin was coupled with aminohydroxyazo-benzene. The product was dimerized to Janus [2]pseudorotaxane, which in turn was bis-azo coupled with 2-naphthol-3,6-disulfonic acid. The product undergoes selfassociation as shown in Figure 14 [44], Note that the final product has o-quinone hydrazone structure. 

Most compounds of this type are cyclic sulfite and sulfate esters of aromatic 1,2-diols as well as anhydrides of aromatic 1,2-disulfonic acids. The simplest representatives with unsubstituted benzene rings are 1,3,2-benzodioxathiole 2-oxide (48) (catechol sulfite), the corresponding 2,2-dioxide (156) (catechol sulfate) and 2,1,3-benzoxadithiole 1,1,3,3-tetroxide (158) (1,2-benzenedisulfonic anhydride). Compound (48) was synthesized by refluxing catechol with thionyl chloride in the presence of pyridine. In a similar fashion, from 2-mercaptophenol 1,2,3-benzoxadithiole 2-oxide was prepared (81AG603). The dioxide (156) was obtained in two steps by reaction of catechol monosodium salt with sulfuryl chloride in benzene at 0-10 °C and subsequent reflux of the intermediate (155) in the presence of pyridine. 

In contrast to benzene and naphthalene compounds, anthraquinone can scarcely be sulfonated with concentrated sulfuric acid because the temperature required is so high that the anthraquinone is largely destroyed. Therefore, fuming sulfuric acid must be used, permitting a lower reaction temperature. Under these conditions, it turns out that it is not possible to introduce a single sulfo group, but a second sulfo group is also introduced. In order to obtain a reasonably pure mono-sulfonic acid, it is necessary to conduct the sulfonation so that only about 50 per cent of the anthraquinone is attacked. Even under such mild conditions, appreciable quantities of disulfonic acids are formed. 

In an iron, porcelain, or enameled vessel provided with stirrer and reflux condenser, 200 grams of benzene is mixed carefully over a period of about 30 minutes with 450 grams of oleum containing 10 per cent SO3. The temperature should not be allowed to rise above 75° until the mixing is complete, then it is raised to 110°. Higher temperatures are not recommended, since the formation of disulfonic acid occurs readily. (Benzenedisulfonic acid is formed more easily than the literature would indicate. See the preparation of benzene-m-disulfonic acid, page 143.) After about 1.5 to 2 hours, the benzene has all disappeared. 

Benzene-m>disulfonic acid is used in the preparation of phenol-m-sulfonic acid and of resorcinol. Further sulfonation of benzene-m-disulfonic acid to the trisulfonic acid is accomplished by heating the sodium salt for several hours at about 250°, in the presence of mercury, with 66 per cent oleum. 

The reaction of di- and polysulfonic acids can usually be carried out so that the replacement of the sulfo groups by hydroxyls takes place stepwise (partial alkali fusion). Thus, phenol-m-sulfonic acid is obtained from benzene-m-disulfonic acid under mild conditions, while resorcinol is formed under more vigorous conditions (see page 144) similarly, naphthalene-l,5-disulfonie acid yields, first, l-naphthol-5-sulfonic acid, then l,5 dihydroxynaphthalene, both valuable azo dye... 

The alkali fusion of benzene-m-disulfonic acid yields resorcinol only in the absence of water. With aqueous sodium hydroxide under pressure, phenol-m-sul-fonic acid is formed, and if the temperature is increased, phenol and decomposition products are formed, but not resorcinol. The formation of some phenol as a byproduct cannot be avoided completely. ... 

Swan [3] prepared a benzene 1,3-disulfonic acid derivative, (III), as a surface coating agent for polyvinylpyrrolidone for subsequent use as a surface modifier on polyvinylchloride urinary catheters. 

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