M-Benzene disulfonate

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

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

When benzene undergoes disulfonation m benzenedisulfomc acid is formed The first sulfonic acid group to go on directs the second one meta to itself... 

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. ... 

Derivation By fusing benzene-m-disulfonic acid with sodium hydroxide. 

Figure 53 BioD of L-lysine dendrimers (left) cationic dendrimer (black bar G3, white bar G4, gray bar o-lysine G4) (right) anionic dendrimer (black bar G3 benzene-4-sulfonate (BS), dark gray bar G4 BS, light gray bar G4 benzene-3,5-disulfonate (BDS), white bar G4 succinate). Reproduced with permission from Kaminskas, L. M. Boyd, B. J. Karellas, P. etal. Mol. Pham. 2007,4,949 and Boyd, B. J. Kaminskas, L. M. Karellas, P. etal. Mol. Pham. 2006, 3, 614. Copyright 2006 American Chemical Society.

Resorcinol (m-dihydroxybenzene) is of greater commercial importance than catechol. It was first produced by Wilhelm Komer in 1868 by alkali fusion of iodophenol. Current industrial processes for resorcinol production are based either on benzene-m-disulfonic acid, which is converted to the dihydroxy com-... 

Arylalkanes and Arylalkenes (Table VIII, p. 181). Diphenylmethane is sulfonated exclusively in the para position rather than in the more hindered ortho position. The 4-sulfonic acid is prepared by treating diphenylmethane with chlorosulfonic acid in chloroform solution at 0 the 4,4 -disulfonic acid, by the action of oleum at 100 . 1,2-Diphenyl-ethane (bibenzyl) when heated with sulfuric acid " jdelds a mixture of a disulfonic acid (probably 4,4 ) and a tetrasulfonic acid. Oleum reacts with stilbene without affecting the olefinic linkage to 3deld a disulfonic acid of unknown structure. Triphenylmethane, sj/m-tetraphenyl-ethane, and tetraphenylethylene yield sulfonic acids containing one sulfo group for each benzene ring, probably in the para position. 

Naphthalene (Table IX, p. 182). The course of the sulfonation of naphthalene is strikingly dependent upon both the reaction temperature and time at low temperatures the product is almost exclusively the -isomer (96%), at 165° the product consists of approximately 85% /5-naphthalenesulfonic acid, 15% a-naphthalenesulfonic acid, and traces of the 1,6-disulfonic acid and of /S-naphthyl sulfone (1%). The pure a-acid is isolated from the former sulfonation as follows the reaction mixture is diluted with water, filtered from unchanged naphthalene, and evaporated somewhat under vacuum at a low temperature the -acid dihydrate separates slowly, and is recrystallized from dilute hydrochloric acid (m.p. 90 ). The pure /3-acid is obtained from the high-temperature sulfonation as follows the reaction mixture is diluted with water and filtered from the sulfone, then shaken with benzene to remove the last traces of the sulfone the water layer is evaporated, and the /3-acid separates as the trihydrate on cooling to 10°. The pure trihydrate (m.p. 83 ) is obtained after several recrystallizations from 10% hydrochloric acid, in which it is practically insoluble at 10 . The trihydrate is converted into the monohydrate (m.p. 124 ) on drying in a desiccator... 

Preparation by reaction of acetic anhydride on p-quinone with concentrated sulfuric acid alone or with benzenesulfonic acid, p-toluenesulfonic acid, dl-camphorsulfonic acid or benzene-m-disulfonic acid at 135° (53 to 70%) [2399]. 

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