Anthraquinone l-

C. A typical aromatic amine. Best prepared by the prolonged action of concentrated ammonia solution at a high temperature upon anthraquinone-l-sulphonic acid in the presence of BaClj and by reduction of the corresponding nitro compound or by amination of the chloroanthraquinone. 

Use of mercuric catalysts has created a serious pollution problem thereby limiting the manufacture of such acids. Other catalysts such as palladium or mthenium have been proposed (17). Nitration of anthraquinone has been studied intensively in an effort to obtain 1-nitroanthraquinone [82-34-8] suitable for the manufacture of 1-aminoanthraquinone [82-45-1]. However, the nitration proceeds so rapidly that a mixture of mono- and dinitroanthraquinone is produced. It has not been possible, economically, to separate from this mixture 1-nitroanthraquinone in a yield and purity suitable for the manufacture of 1-aminoanthraquinone. Chlorination of anthraquinone cannot be used to manufacture 1-chloroanthraquinone [82-44-0] since polychlorinated products are formed readily. Consequentiy, 1-chloroanthraquinone is manufactured by reaction of anthraquinone-l-sulfonic acid [82-49-5] with sodium chlorate and hydrochloric acid (18). 

In the anthraquinone series, apart from the special case of the amination of leucoquinizarin, sulfonic acid and nitro are the preferred leaving groups. 1-Aminoanthraquinone is manufactured from anthraquinone-l-sulfonic acid or 1-nitroanthraquinone, and 2-amino anthraquinone (betamine) from anthraquinone-2-sulfonic acid. 

Anthraquinone-l-sulfonic acid and Its Derivatives. Anthraquinone-l-sulfonic acid [82-49-5] (16) has become less competitive than 1-nitroanthraquinone as the intermediate for 1-aminoanthraquinone. However, it still has a great importance as an intermediate for manufacturing vat dyes via 1-chloroanthraquinone. 

Chloroanthraquinone [82-44-0] (41) is an intermediate for manufacturing vat dyes such as Cl Vat Brown 1. 1-Chloroanthraquinone is prepared by chlorination of anthraquinone-l-sulfonic acid with sodium chlorate in hydrochloric acid at elevated temperature (61). An alternative route from 1-nitroanthraquinone (18) using elemental chlorine at high temperature has been reported (62). 

Anthraquinone-l,5-disulfonic acid [117-14-6] (44), and anthraquinone-1, 8-disulfonic acid [82-48-4] (45) are produced from anthraquinone by disulfonation in oleum a higher concentration of SO than that used for 1-sulfonic acid is employed in the presence of mercury catalyst (64,65). After completion of sulfonation, 1,5-disulfonic acid is precipitated by addition of dilute sulfuric acid and separated. After clarification with charcoal, 1,5-disulfonic acid is precipitated as the sodium salt by addition of sodium chloride. The 1,8-disulfonic acid is isolated as the potassium salt from the sulfuric acid mother hquor by addition of potassium chloride solution. 

Anthraquinone dyes have been produced for many decades and have covered a wide range of dye classes. In spite of the complexity of production and relatively high costs, they have played an important role in the areas where excellent properties ate requited, because they have excellent lightfastness and leveling properties with brUhant shades that ate not attainable with other chtomophotes. However, recent increases in environmental costs have become a serious problem, and future prospects for the anthraquinone dye industry ate not optimistic. Some traditional manufacturers have stopped the production of a certain dye class or dye intermediates that were especially burdened by environmental costs, eg, vat dyes and their intermediates derived from anthraquinone-l-sulfonic acid and 1,5-disulfonic acid. However, several manufacturers have succeeded in process improvement and continue production, even expanding their capacity. In the forthcoming century the woddwide framework of production will change drastically. 

Sodium anthraquinone-l,5-disulfonate (HjO) [853-35-0] M 412.3. Separated from insoluble impurities by continuous extraction with water. Crystd twice from hot water and dried under vacuum. 

Sodium anthraquinone-l-sulfonate (HjO) [107439-61-2] M 328.3. Crystd from hot water (4mL/g) after treatment with active charcoal, or from water by addition of EtOH. Dried under vacuum over CaCl2, or in an oven at 70°. Stored in the dark. 

In an interesting study, phthalocyanine complexes containing four anthraquinone nuclei (5.34) were synthesised and evaluated as potential vat dyes and pigments [18]. Anthraquinone-1,2-dicarbonitrile or the corresponding dicarboxylic anhydride was reacted with a transition-metal salt, namely vanadium, chromium, iron, cobalt, nickel, copper, tin, platinum or lead (Scheme 5.6). Substituted analogues were also prepared from amino, chloro or nitro derivatives of anthraquinone-l,2-dicarboxylic anhydride. 

As noted in the Introduction sulfenic acids are generally unstable and reactive. A few, namely, anthraquinone-1-sulfenic acid [1], anthraquinone-l,4-di-sulfenic acid [2], and the sulfenic acid [3] (generated by thermolysis of sulfoxide [4]) have, however, been isolated as pure crystalline compounds (Bruice and Sayigh, 1959 Bruice and Markiw, 1957 Chou et al., 1974). Another sulfenic acid that appears to be of considerable stability is the pyrimidine derivative [5]. The silver salt of [5] was isolated by Pal et al. (1969) from the alkaline hydrolysis of the corresponding disulfide. The free sulfenic acid [5] was then liberated in solution by treating the silver salt with dilute aqueous hydrochloric acid and filtering off the silver chloride formed. Solutions... 

More reliable reagents for the preparation of sulfinic acids are zinc [694, 695], sodium sulfide [249] and sodium sulfite [2S2. These reagents not only stop the reduction at the stage of the sulfinic acids (in the form of their salts) but do not reduce other functions present in the molecules. In the reduction of anthraquinone-l,5-disulfonyl chloride with sodium sulfide below 40° anthraquinone-l,5-disulfinic acid was obtained in 83.5% yield [249], and p-cyanobenzenesulfonyl chloride was reduced to p-cyanobenzenesulfinic acid in 87.4% yield [252]. 

Only a few qui nones react with sulfur tetrafluoride in the normal way by replacing each carbonyl group by two fluorine atoms. The examples are 9,10-anthraquinone (l),41 phenanthrene-9,10-quinone (2),100 and acenaphthoquinone and its substituted derivatives 3.101102 The reactions proceed at 150-300 C, preferably in the presence of anhydrous hydrogen fluoride. 

Amino-3,7-disull o-9.10-anthraquinon-l-ylamino)-anilino]-5-chloro-2.4-difluoro-ElOa. 74 (Educt)... 

Zn(anthraquinon-l-olate)2, 86 ZnC30H28N2S4 Zn SXN(CH2Ph)2 2, 98 ZnC32H12N8012S4 [Zn (03S)4pTithalocyanine ]4, 513 ZnC32H16N8 Zn(phthalocyanine), 511 ZnC36H20N4... 

The copper-catalysed, Ullman-type coupling of aryl, heteroaryl and alkenyl halides may be achieved at ambient temperature using copper(I) thiophene-2-carboxylate as catalyst.60 A new semiconducting poly(anthraquinone-l,5-diyl) with nitro groups at the 4- and 8-positions has been prepared by Ullman-type coupling using metallic copper or a zerovalent nickel complex as catalyst.61... 

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