Anthraquinone-dyestuffs

The ability of the 1-hydroxyanthraquinone system to form chelate complexes is, however, still employed in the synthesis of certain anthraquinone dyestuffs since it permits selective reactions to be carried out. Thus, treatment of the borate ester (215) of 1,2-dihydroxyanthraquinone with acetic anhydride yields l-hydroxy-2-acetoxyanthraquinone, the 1-hydroxy group being protected against electrophilic attack as a result of its being involved in coordination to boron. 

In this paper solubility measurements of synthetic and natural dyestuffs are presented using VIS-spectroscopy. The investigations concentrate on two different methods. I. P-carotene was measured as a function of temperature and pressure in near- and supercritical C02 (289 to 309 K, 10 to 160 MPa) and CC1F3 (297 to 326 K, 12 to 180 MPa), respectively, using a static method. II. Additionally, the solubilities of l,4-bis-(n-alkylamino)-9,10-anthraquinones (with n-alkyl = butyl, octyl) were determined with a dynamic method in temperature and pressure ranges from 310 to 340 K and 8 to 20 MPa, respectively this method permits a continuous purification from better soluble impurities as well as the measurement of solubilities at the same time. For both anthraquinone dyestuffs intersection points of the solubility isotherms were found in the plot of concentration versus pressure. This behavior can be explained by a density effect. 

Aromatic sulfonates Educts for azo and anthraquinone dyestuffs, intermediates in ion-exchange resin production, pesticides, pharmaceuticals, wetting agents, optical brigjiteners, tanning agents, plasticizers Water... 

The totally enclosed List sublimation unit Figure 8.33) is provided with selfcleaning heat exchange surfaces and operates semi-continuously under reduced pressure without the aid of a carrier gas. Accumulated impurities are discharged from the sublimator periodically. Batch and continuous modifications of this unit are available (Schwenk and Raouzeos, 1995) and have been successfully applied industrially for the purification of anthraquinone, dyestuffs intermediates, metal-organic compounds and pharmaceuticals with production rates ranging from 300 to 10000 ton/year. 

Whereas alizarin has been replaced commercially by modern dyestuffs, related anthraquinone dyestuffs offer at least potentially attractive fields of application. 

Anthracene was first discovered in coal tar by Jean B.A. Dumas and Auguste Laurent in 1832. The importance of anthracene for industrial aromatic chemistry began with the synthesis of the dyestuff alizarin by Carl Graebe and Carl Th. Liebermann, as well as by William H. Perkin in 1868, replacing the natural dye produced from madder. Anthraquinone dyestuffs have remained the most important class of dyes, alongside azo-dyes, since the beginning of the chemistry of synthetic dyestuffs. 

By far the most versatile synthetic anthraquinone dyestuffs are based on anthra-quinone derivatives which are substituted in the 1-, 1,4-, 1,5- and 1,8-positions 1,2-substituted derivatives, as in the case of alizarin, are also significant. 

Bromamine acid (l-amino-4-bromoanthraquinone-2-sulfonic acid) is the most important intermediate for the production of acid anthraquinone dyestuffs. 

Swidersky, P., Tuma, D., and Schneider, G.M. (1996) High-pressure investigations on the solubility of some homologous anthraquinone dyestuffs in supercritical gases by VIS-spectroscopy. Part II - l,4-Bis-(n-alkylajnino)-9,10-anthraquinones and Disperse Red 11 in CO2, N2O, and CHF3 up to 180 MPa, J. Supercrit. Fluids 9, 12-18. 

Tuma, D. (1999), Spectroscopic high-pressure investigations in near and supercritical fluids up to 180 MPa — Solubility and stability of anthraquinone dyestuff s and /3-Carotene in CO2, N2O, CCIF3, and SFe (in German), Doctoral dissertation, University of Bochum, Germany. 

Various species of Rubia (Rubiaceae) produce the dyestuff known commonly as madder (. v.) the most common species are Rubia tinctorum L. R. peregrina L. R. cordifolia L. R. sikkimensis Kurz. R. akane Hakm R. iberica C. Koch R. rigid-ifolia Pojark (Schweppe, 1992 Schweppe and Winter, 1997). For a fuller discussion of the various members of the Rubiaceae that produce madder-related anthraquinone dyestuffs, see the entry for madder. 

The excellent photostability of the anthraquinone dyestuffs are related to the introduction of a proton donor in the a-posi-tion of the anthraquinone molecule [58], The anthraquinone molecule itself has no absorption band in the visible spectrum [46], so at least one of the 1,4, 5, or 8 (or 2,... 

It is an important dyestuffs intermediate. It condenses with chloroethanoic acid to give phenylglycine-o-carboxylic acid for the synthesis of indigo. It can be diazotized and used as a first component in azo-dyes it condenses also with chloroanthraquinones to give intermediates for anthraquinone dyes. 

Only the reduction products involving the keto groups are of any academic or industrial importance. Complete reduction of the keto groups by ammonia and zinc (von Perger method) gives rise to anthracene in good yields and quaUty (10). This method is of importance since substituted anthracenes can be prepared from the corresponding anthraquinones. Industrially, an important dyestuff intermediate, 3-chloroanthracene-2-carboxyhc acid, (2) is prepared by this method (11) from 3-chloroanthraquinone-2-carboxyhc acid [84-32-2]... 

In the dyestuff industry, anthraquinone still ranks high as an intermediate for the production of dyes and pigments having properties unattainable by any other class of dyes or pigments. Its cost is relatively high and will remain so because of the equipment and operations involved in its manufacture. As of May 1991, anthraquinone sold for 4.4/kg in ton quantities. In the United States and abroad, anthraquinone is manufactured by a few large chemical companies (62). At present, only two processes for its production come into consideration manufacture by the Friedel-Crafts reaction utilizing benzene, phthahc anhydride, and anhydrous aluminum chloride, and by the vapor-phase catalytic oxidation of anthracene the latter method is preferred. 

Heterocyclic Azo Dyes. One long-term aim of dyestuffs research has been to combine the brightness and high fastness properties of anthraquinone dyes with the strength and economy of azo dyes. This aim is now being realized with heterocychc azo dyes, which fall into two main groups those derived from heterocychc coupling components, and those derived from heterocychc diazo components. 

The appearance of synthetic fibers in the 1920s accelerated the further development of anthraquinone dyes. Soon after British Celanese succeeded in commerciali2ing cellulose acetate fiber in 1921, anthraquinone disperse dyes for this fiber were invented by Stepherdson (British Dyestuffs Corp.) and Celatenes (Scottish Dyes) independendy. Anthraquinone disperse dyes for polyester fiber were developed after the introduction of this fiber by ICI and Du Pont in 1952. These dyes were improved products of the disperse dyes that had been developed for cellulose acetate fiber 30 years before. 

Anthraquinone dyes are derived from several key compounds, ie, dye intermediates. Production of these dye intermediates often requires sophisticated production processes and a large amount of investment in plant constmction. The competitiveness of final products, dyestuffs, depends on that of the intermediates, ie, quaUty, cost, and availabiUty. 

In addition to these, some anthraquinone dyes and their intermediates are also produced in Eastern Europe, Russia, China, and Korea. As the result of the history of anthraquinone chemistry, most manufacturers are still located in Western Europe. Most former manufacturers in the United States abandoned the dyestuff business or were acquired by European companies by the middle of the 1980s. 

HPLC ESI MS is also a useful tool in the analysis of non-anthraquinone red dyestuffs. The use of this technique allows the identification of carthamin as the main colour component of safflower.[34] Ten species of the genus Alkanna are extracted with hexane, and dissolved in water-methanol solution after evaporation. [47] Ammonium formate buffer (pH 3.0) was used as the mobile phase modifier. In the preparations, alkannin and many hydroxynaphthoquinones (alkannin derivatives) were identified by comparison of retention times, as mass spectra (in the NI mode) for all compounds consisted only of quasi-molecular peaks. 

M.A. Ackacha, K. Polec Pawlak and M. Jarosz, Identification of anthraquinone coloring matters in natural red dyestuffs by high performance liquid chromatography with ultraviolet and electrospray mass spectrometric detection, J. Sep. Sci., 26, 1028 1034 (2003). 

Acid dye affinity, 19 759 Acid dyes, 9 184-186, 189-190, 215-216, 226, 243 26 395-396 anthraquinone, 9 301, 327-329 azo, 9 389-394 Acid dyestuffs, 9 223 Acid extractants, 10 750 Acid fixing reactive dyes, 9 478-481 Acid foods, heat preservation of, 12 80 Acid functional polyesters, 10 402 Acid gas constituents, 12 376-378 Acid gases, 10 612-613... 

Basic chrome sulfate, 6 543 Basic copper chromate, molecular formula, properties, and uses, 6 561t Basic detergents, 15 222 Basic (cationic) dyes, 9 217, 242-243 anthraquinone, 9 301 azo, 9 421 24 Basic dyestuffs, 9 224 Basic extractants, of rare-earth elements, 14 642... 

More extensive studies using somewhat higher wavelengths have been reported by Geacintov et al. (111, 112). These authors used phototendering dyestuffs notably the sodium salt of anthracene 2,7 disulfonic acid as the sensitizer in aqueous solution. For grafting to cellulose acetate and ethyl cellulose 2-methyl anthraquinone which is soluble in organic solvents was used. The mechanism proposed was the removal of a... 

Anthracyclinones The anthraquinone 1, available from the commercial dyestuff l,4,5-trihydroxy-9,10-anthraquinone, reacts regiospecifically because of the halo substituent with 2-methoxybutadiene to give 2. The product can be converted by ketalization and oxidation into the quinone 3, a known precursor to anthracyclinones. 

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