Anthraquinonesulfonic Acids

Until fairly recently, preparation of almost 80 % of all important anthraquinones was based on anthraquinonesulfonic acids. However, nitration of anthraquinone is gaining in importance presently, a development triggered mainly by environmental considerations (e g., production of large volumes of waste dilute acids during anthraquinone sulfonation). However, great progress has been made recently in solving the problems associated with sulfonation. 

Preparation of nearly all important anthraquinones starts from the following key intermediates anthraquinonesulfonic acids, nitroanthraquinones, and the products of nucleus synthesis, 1,4-dihydroxy-, 2-methyl-, and 2-chloroanthraquinone. The only exceptions are derivatives with condensed rings, e.g., benzan-throne and derived products, which are prepared directly from anthraquinone via anthrone. 

Nitration of anthraquinonesulfonic acids follows the same general pattern as in the naphthalene series. A mixture of various isomers is always formed, and of these the 1,5 derivative is easily separated, the others with more difficulty. 

Technical Observations. The solution of ammonium sulfite formed by the action of ammonia on anthraquinonesulfonic acid has a deleterious action on the end product. The sulfite must be removed, therefore, by oxidizing it to the sulfate. 

The hydroxylation of aromatic compounds takes place on heating with solid potassium hydroxide of compounds with low electron density in the ring and occurs in positions prone to nucleophilic attack. Nitrobenzene is converted into o-nitrophenol on heating with potassium hydroxide for 2 h at 60-70 °C (yield 45%) [485]. Quinoline gives carbostyril (2-hydroxyqui-noline) on heating with potassium hydroxide for 3 h at 225 °C (yield 77%) [486], A historically important reaction is the hydroxylation of both a- and P-anthraquinonesulfonic acid by alkali fusion to yield alizarin (1,2-dihy-droxyanthraquinone). 

Aniline Hydrochloride Animal Oils Anthraquinone Anthraquinonesulfonic Acid Antimony Trichloride ... 

Allyl Mustard Oil 57-06-7 Ammonium Hydrogen Carbonate 1066-33-7 Anthraquinonesulfonic Acid 30637-95-7... 

The FD mass spectra of the di-n-butylammonium salts of a few naphthalene- and anthraquinonesulfonic acids have been reported38. The spectra were dominated by the [Bu2NH2] + ion ([Cat]+). Naphthalene-1-sulfonic acid dibutylammonium salt showed a major [M + Cat] + ion while more abundant ions were [M + H] + in the spectrum of naphthalene-2,6-disulfonic acid di-dibutylammonium salt and [M — Cat + 2H] + in the spectrum of naphthalene-1,3,6-trisulfonic acid tri-dibutylammonium salt. 

Encyclopedia of Chemical Technology/ Anthraquinonesulfonic Acids Ltjbs, pp. 335 f. Venkataraman, op. ciL, vol. 1, pp. 59ff. Fierz-David, pp. 234if. 

Ammonolysis of Anthraquinonesulfonic Acids. The replacement of the —SO3H group by —NHj is limited to the anthraquinone series. The amination can be carried out readily at 165°C with concentrated aqueous ammonia. Compared with the similar ammonolysis of halogenoanthra-quinones, the reaction takes place at lower temperatures and purer amines can be obtained. 

The need of oxidants in the ammonolysis of anthraquinonesulfonic acids has long been recognized. If it is not oxidized, the sulfurous acid that is split off gives rise to the formation of soluble reduction products. The yield of 2-aminoanthraquinone, according to the following reaction, is consequently only about 60 per cent of the theoretical ... 

Lauer has found that inorganic oxidants have a specific value, depending on the particular anthraquinonesulfonic acid undergoing treatment as well as on the operating conditions employed. Certain oxidants give rise to impurities that are not entirely removed by simple technical purification. When present even in traces, the impurities may interfere with the use of the amine in dyestuffs, this, in the final analysis, being the best criterion of purity. 

Solubility. The soluble anthraquinonesulfonic acids are more readily converted to amines than the insoluble halogeno compounds. A similar... 

Other Names 2-Anthraquinonesulfonic acid, 3,4-dihydroxy-, sodium salt Acid Mordant Red SW Acid Red Alizarine Ahcoquinone Red S Alizarin Carmine Alizarin Red S Alizarin S Alizarine Carmine Alizarine Carmine Indicator Alizarine Red A Alizarine Red AS Alizarine Red Indicator Alizarine Red S Alizarine Red S sodium salt Alizarine Red SW Alizarine Red SZ Alizarine Red W Alizarine Red WA Alizarine Red WS Alizarine Red for Wool Alizarine S Alizarine S Extra Cone. A Export Alizarine S Extra Pure A Alizarinsulfonate C.l. 58005 C.l. Mordant Red 3 Calcochrome Alizarine Red SC Camelio Rubine Lake Chrome Red Alizarine Diamond Red W Ext D and C Red No. 7 Eenakrom Red W Mitsui Alizarine Red S Mordant Red 3 Oxanal Fast Red SW Sodium 3,4-dihydroxyanthraquinone-2-sulfonate Sodium aUzarin-3-sulfonate Sodium alizarinesulfonate Sodium alizarinsulfonate CA Index Name 2-Anthracenesulfonic acid, 9,10-dihydro-3,4-dihydroxy-9,10-dioxo-, monosodium salt... 

In the naphthalene series, direct chlorination seldom is used. The reaction takes place readily but leads to numerous isomers. In the anthraquinone series, both direct and indirect chlorination are employed. An example of indirect chlorination is the conversion of 1-anthraquinonesulfonic acid to the corresponding chloro compound. This reaction is carried out at approximately 100°C with sodium or potassium chlorate in hydrochloric acid. 

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