Alizarin derivatives

Aliphatic solvents, alkyllithium compounds and, 14 250-251 Aliphatic sulfonates, 26 145 Aliquot samples, 13 413-415 analysis of, 13 416 Aliskren, 5 158 Alitame, 12 42 24 232 Alite, phase in Portland cement clinker, 5 471, 472t, 473t Alitretinoin, 25 790 Alizarin, color of, 7 331 Alizarin derivatives, 9 337 Alizarin pure Blue B, 4 361t Alkadienes, metathesis of, 26 923 Alkali/alkaline-earth cation recognition,... 

An interesting variation on the chelate formation of alizarin derivatives is the production of Turkey red, a brilliant red dye known from ancient times. Recipes for its production insist not only on aluminum, but on lime, in order to achieve the red-purplish color and the high fastness properties for which it is famed. Its probable structure is shown in Figure 8 10), Some modem mordant dyestuffs derived from alizarin are shown in Table IV. 

Anlhraquinone-2-su phonic acid. The sodium salt, commonly called silver salt , is used for the preparation of alizarin and 2-aminoanthraquinone and to prepare Fieser s solution. Aminoanthraquinone derivatives are the basis of many dyestuffs. 

Anthraquinone is of great technical importance, as many of its derivatives form valuable dyes notable among these are the hydroxy-derivatives (alizarin, etc.)y the amino-derivatives (indanthrene, etc.) and the sulphonic acids. 

Qumones are colored p benzoqumone for example is yellow Many occur natu rally and have been used as dyes Alizarin is a red pigment extracted from the roots of the madder plant Its preparation from anthracene a coal tar derivative m 1868 was a significant step m the development of the synthetic dyestuff industry... 

Anthraquinone [84-65-1] has yet to be found in nature, although some of its substitution products have been known since antiquity (alizarin, kermes, cochineal, and lac dye). Of all the quinones found naturally, those derived from anthraquinone far exceed all others. Many of these are found in molds (2). 

A variety of derivatives have been produced from alizarin and used as mordant dyes for cotton and wool. Examples are given in Table 7. 

Phenolic antioxidants in rubber extracts were determined indirectly photometrically after reaction with Fe(III) salts which form a red Fe(II)-dipyridyl compound. The method was applicable to Vulkanox BKF and Vulkanox KB [52]. Similarly, aromatic amines (Vulkanox PBN, 4020, DDA, 4010 NA) were determined photometrically after coupling with Echtrotsalz GG (4-nitrobenzdiazonium fluoroborate). For qualitative analysis of vulcanisation accelerators in extracts of rubbers and elastomers colour reactions with dithio-carbamates (for Vulkacit P, ZP, L, LDA, LDB, WL), thiuram derivatives (for Vulkacit I), zinc 2-mercaptobenzthiazol (for Vulkacit ZM, DM, F, AZ, CZ, MOZ, DZ) and hexamethylene tetramine (for Vulkacit H30), were mentioned as well as PC and TLC analyses (according to DIN 53622) followed by IR identification [52]. 8-Hydroquinoline extraction of interference ions and alizarin-La3+ complexation were utilised for the spectrophotometric determination of fluorine in silica used as an antistatic agent in PE [74], Also Polygard (trisnonylphenylphosphite) in styrene-butadienes has been determined by colorimetric methods [75,76], Most procedures are fairly dated for more detailed descriptions see references [25,42,44],... 

There is a wide diversity of chemical structures of anthraquinone colorants. Many anthraquinone dyes are found in nature, perhaps the best known being alizarin, 1,2-dihydroxyanthraquinone, the principal constituent of madder (see Chapter 1). These natural anthraquinone dyes are no longer of significant commercial importance. Many of the current commercial range of synthetic anthraquinone dyes are simply substituted derivatives of the anthraquinone system. For example, a number of the most important red and blue disperse dyes for application to polyester fibres are simple non-ionic anthraquinone molecules, containing substituents such as amino, hydroxy and methoxy, and a number of sul-fonated derivatives are commonly used as acid dyes for wool. 

The first quinoline derivative obtained by the process (a) was the dye alizarin blue (Prud homme, 1877). f -Nitroaliza,rin was heated with glycerol and sulphuric acid. The constitution of the product was established by Graehe ... 

Anthracene was oxidized to anthraquinone. dibrominated, and the dibromo derivative subjected to a caustic fusion. Alizarin was obtained in an impure form and in low yield. This represented the first synthesis of a natural dye. 

Reaction LVIIL (a) Reduction of Phenols and Quinones by Distillation with Zinc Dust. (A., 140, 205.)—When certain aromatic oxygen compounds (phenols, naphthols, quinones, etc.), are heated with zinc dust, they are reduced to the corresponding hydrocarbons. Thus, phenol yields benzene, the naphthols naphthalene while anthracene can be obtained from anthraquinone or its hydroxy derivatives, alizarin, or quinizarin. In this way alizarin was first proved to be an anthracene derivative. (B., 1, 43.) For catalytic reduction of phenols, see C. r. 193, 1023. 

The more common and more important red lakes are those of cochineal, red wood, alizarin (or madder) and its derivatives, triphenylmethane dyes (fuchsine), safranine, eosin, developed and sulphonated azo-dyes the last give also orange lakes. 

Besides these, use is also made (especially for dyeing wool), under the name of alizarin red, of the sodium salts of the respective sulphonic derivatives, which form orange-yellow powders... 

Commercial alizarin may be contaminated with anthraquinone and its derivatives devoid of tintorial value, such as hydroxyanthraquinone and certain dihydroxyanthraqu inones (anthraflavic and isoant hr aflavic... 

Qualitative Reactions.—Alizarin is insoluble in water, but soluble in boiling alcohol or in ether it dissolves in sodium hydroxide solution, giving a solution which is violet-blue for pure alizarin, violet for anthra-purpurin, purple-red for flavopuipurin, and red for purpurin. The sul-phonic derivatives are soluble in water and give violet alkaline solutions. 

Various Anthraquinone Derivatives.—These may be determined approximately in commercial alizarin by the following method (Benedikt and Knecht) ... 

Some of these structures retain the methyl from the isoprenyl substituent, whilst in others this has been removed, e.g. alizarin from madder (Rubia tinctomm Rubiaceae), presumably via an oxidation-decarboxylation sequence. Hydroxylation, particularly in the terpenoid-derived ring, is also a frequent feature. 

Erk developed a spectrophotometric procedure for the assay of atorvastatin, both for the bulk drug substance as well as for pharmaceutical formulations. The procedures are based on the reaction between the drug and bromocresol green, alizarin red, or bromophenol blue, which result in the production of ion-pair complexes (1 1). Beer s law was obeyed over the concentration ranges 5.0-53.0, 7.1-55.8, or 7.5-56.0 /ig/ml with bromocresol green, alizarin red, and bromophenol blue, respectively. The specific absorptivities, molar absorptivities, Sandell sensitivities, standard deviations, and the percent recoveries were evaluated. Atorvastatin was determined by measurement of its first derivative signal at 217.8 nm. 

The fiber is first treated with metal salts (mordanted). Highly adhesive, basic metal compounds are formed on the fiber. These compounds are capable of producing insoluble colored complexes (lakes) with certain azo and anthraquinone derivatives. Alizarin is the best-known anthraquinone derivative for this process (see Section 2.3). It used to be isolated from the root of the madder plant but has now been replaced by the synthetic product. Suitable azo dyes contain, e.g., hydroxyl or carboxyl groups in the position ortho to the azo group on one or both of the aromatic nuclei. The shade of the dyeing depends on the type of metallic mordant used. Alizarin with aluminum or calcium salts produces the well-known Turkey red. 

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