Anthraquinone derivative

Although considered an active participant in the process cycle, the tetrahydroaLkylanthraquinone (10) may not be a significant part of the catalytic hydrogenation because, dependent on the concentration in the working solution, these could all be converted to the hydroquinone by the labile shift per equation 17 and not be available to participate. None of the other first- or second-generation anthraquinone derivatives produce hydrogen peroxide, but most are susceptible to further reaction by oxidative or reductive mechanisms. 

Other Reactions. Phthabc anhydride (1) undergoes condensation to form anthraquinone derivatives ... 

In 1901, mercury cataly2ed a-sulfonation of anthraquinone was discovered, and this led to the development of the chemistry of a-substituted anthraquinone derivatives (a-amino, a-chloro, a-hydroxy, and a,a -dihydroxyanthraquinones). In the same year R. Bohn discovered indanthrone. Afterward flavanthrone, pyranthrone, and ben2anthrone, etc, were synthesi2ed, and anthraquinone vat dyes such as ben2oylaniinoanthraquinone, anthrimides, and anthrimidocarba2oles were also invented. These anthraquinone derivatives were widely used to dye cotton with excellent fastness, and formed the basis of the anthraquinone vat dye industry. 

The main by-products of the Ullmaim condensation are l-aniinoanthraquinone-2-sulfonic acid and l-amino-4-hydroxyanthraquinone-2-sulfonic acid. The choice of copper catalyst affects the selectivity of these by-products. Generally, metal copper powder or copper(I) salt catalyst has a greater reactivity than copper(Il) salts. However, they are likely to yield the reduced product (l-aniinoanthraquinone-2-sulfonic acid). The reaction mechanism has not been estabUshed. It is very difficult to clarify which oxidation state of copper functions as catalyst, since this reaction involves fast redox equiUbria where anthraquinone derivatives and copper compounds are concerned. Some evidence indicates that the catalyst is probably a copper(I) compound (28,29). 

In order to develop the dyes for these fields, characteristics of known dyes have been re-examined, and some anthraquinone dyes have been found usable. One example of use is in thermal-transfer recording where the sublimation properties of disperse dyes are appHed. Anthraquinone compounds have also been found to be usehil dichroic dyes for guest-host Hquid crystal displays when the substituents are properly selected to have high order parameters. These dichroic dyes can be used for polarizer films of LCD systems as well. Anthraquinone derivatives that absorb in the near-infrared region have also been discovered, which may be appHcable in semiconductor laser recording. 

A series of anthraquinone derivatives 92 are reported to provide good yields of 93 (Eq. 12 ) (83KGS1621, 85ZOR1959). 

Note Monohydroxybenzene derivatives and vicinal hydroxymethoxybenzene derivatives do not react under these conditions but can be made visible by spraying afterwards with Folin-Qocalteu s reagent [1]. Flavonoids, anthraquinone derivatives and a-nitroso-B-naphthol yield a red color with alkalis alone [1]. Steroids and aromatic amines do not react [1]. 

The chromatograms are dried in a stream of cold air, first sprayed homogeneously with the reagent and, as in the case of anthraquinone derivatives, they are then dried in a steam of warm air for a few minutes [10] or at room temperature for 20 min [11]. In the case of pesticides the chromatogram is covered by a glass plate and heated to 100-200°C for up to 30 min [16]. 

Much toxicological data are available on this red pigment acute oral toxicity in mice, 90-day subchronic toxicological study, acute dermal irritation and corrosion, acute eye irritation and corrosion, anti-tumor effectiveness, micronucleus test in mice, AMES test Salmonella typhimurium reverse mutation assay), estimation of antibiotic activity, and results of estimation of five mycotoxins. A new patent on Arpink Red was filed in 2001 with claims of anti-cancer effects of the anthraquinone derivatives and apphcations in the food and pharmaceutical fields. 

Water-soluble polymeric dyes have been prepared from water-insoluble chromophores, viz., anthraquinone derivatives. Unreacted chromophore and its simple derivatives, which are all water-insoluble, remain in solution due to solubilization by the polymeric dye. A method has been developed to separate and quantitate the polymeric dye and these hydrophobic impurities using Sephadex column packing. The solvent developed has the property of debinding the impiirities from the polymer, and further allows a separation of the imp irities into discrete species. This latter separation is based on the functional groups on the impurity molecules, having a different interaction with the Sephadex surface in the presence of this solvent. The polymer elutes at the void volume... 

Oxidative repair is not a unique feature of our Rh(III) complexes. We also demonstrated efficient long-range repair using a covalently tethered naphthalene diimide intercalator (li /0 1.9 V vs NHE) [151]. An intercalated ethidium derivative was ineffective at dimer repair, consistent with the fact that the reduction potential of Et is significantly below the potential of the dimer. Thymine dimer repair by a series of anthraquinone derivatives was also evaluated [151]. Despite the fact that the excited triplets are of sufficient potential to oxidize the thymine dimer ( 3 -/0 1.9 V vs NHE), the anthraquinone derivatives were unable to effect repair [152]. We attribute the lack of repair by these anthraquinone derivatives to their particularly short-lived singlet states anthraquinone derivatives that do not rapidly interconvert to the excited triplet state are indeed effective at thymine dimer repair [151]. These observations suggest that interaction of the dimer with the singlet state may be essential for repair. 

Photochemical nucleophilic substitution of some simple anthraquinone derivatives has been reported by Griffiths and Hawkins.<145) Irradiation of 1-methoxyanthraquinone (90) in ammonia solution resulted primarily in 1-aminoanthraquinone (91) ... 

Beng W, Hesse A, Herramann M, Kraft R. Structure elucidation of a new anthraquinone derivatives from Rubia tinctorium. Pharmazie 1975 30 330-334. 

Table 12.36 Peak cathodic potentials of anthraquinone derivatives measured using Ag/AgCI/3M KCI in 4 g/l sodium hydroxide solution [239]...

Figure 2.6 Anthraquinone derivatives can photoreactively couple to substrates by means of a free radical generation process. The reactive intermediate also can be regenerated back to the initial anthraquinone by proton abstraction and oxidation, resulting in the possibility of again being photolyzed and successfully coupled to the substrate.

Anthraquinol + 02 —i> Anthraquinone + H202 The anthraquinone derivative is usually 2-ethyl- or 2-pentyl-anthraquinone. The solvent is usually a mixture of two solvents, one for the quinone and one for the quinol. The... 

Table 5 Association and dissociation rate constants for anthraquinone derivatives with ct-DNA and polydeoxynucleotides from ref. 101...

An example of industrial interest is the benzanthrone (9) synthesis. Benzan-throne derivatives are manufactured by cathodically reducing anthraquinone derivatives that may contain electronegative substituents [61]. In the cathode compartment the reduction of anthraquinone (7) in 85% H2S04 to oxanthrone (8) occurs which in presence of glycerol reacts to form benzanthrone (9), which is an important dye intermediate [40, 61]. 

Vat dyes are used to colour both components in pale depths on polyester/cellulosic fibre blends [44] but coloration of the polyester component in this case is more closely analogous to disperse dyeing (section 1.6.5). Anthraquinone disperse dyes resemble those vat dyes that are substituted anthraquinone derivatives and in both instances it is exclusively the virtually water-insoluble keto form that is absorbed by the polyester fibre. 

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