Anthraquinone heterocyclic

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. 

Anthraquinone dyes are second only to azo dyes in importance as disperse dyes and are predominant in the red, violet, blue and blue-green sectors [14]. Because anthraquinone disperse dyes are relatively expensive to manufacture, successful attempts were made to replace some of them with technically equivalent and more economical products [15]. The replacement process has been most successful in the red region using, for example, heterocyclic azo dyes and novel chromogens. The brilliance of the anthraquinones with their narrow spectral absorption bands is difficult to attain with other structures, however, as is their high light fastness and chemical stability. The development of anthraquinone disperse dyes is included in a review by Dawson [16]. 

Heterocyclic ring systems are also used to connect two anthraquinone groups. Typical examples include Cl Vat Red 10 (6.106), which is an oxazole derivative obtained from 2-amino-3-hydroxyanthraquinone and the appropriate acyl chloride, the similar thiazole derivative Cl Vat Blue 31 (6.107) and the oxadiazole derivative Cl Vat Blue 64 (6.108). 

This chapter classifies polycyclic pigments by chemical constitution. The resulting classes include aminoanthraquinones, hydroxyanthraquinones, heterocyclic and polycarbocyclic anthraquinone pigments. 

As a group, these pigments include compounds whose heterocyclic system is formally derived from the anthraquinone nucleus. 

Directed metalatioru orf/io-Metalation of bcnzamides has been used for a one-pot route to polycyclic anthraquinones and heterocyclic benzoquinones.1 Example ... 

Other five-membered heterocycles such as thiophenes, thiazoles and oxazoles have been successfully annellated in the anthraquinone series. For example, the yellow dye (12) may be prepared from 2,6-diaminoanthraquinone by condensation with benzotrichloride and sulfur. Similarly, the six-membered heterocycles acridines, quinoneazines, pyrazines, acridones and pyrimidines are frequently incorporated (B-52MI11201). In fact, the best known of the anthraquinone vat dyes are indanthrone (13) and flavanthrone (14). The former anthraquinoneazine, a beautiful blue, which was the first such structure to be manufactured on a large scale, may be prepared by alkali fusion of 2-aminoanthraquinone at 220 °C (27MI11200). Treatment of 2-aminoanthraquinone in nitrobenzene with antimony pentachloride yields the yellow flavanthrone (14), the structure being confirmed by Scholl (07CB1691). Both indanthrone and flavanthrone and their derivatives have attracted considerable commercial attention. 

The carbocyclic azo dye class provides dyes having high cost-effectiveness combined with good all-around fastness properties. However, they lack brightness, and consequently, they cannot compete with anthraquinone dyes lor brightness. This shortcoming of carbocyclic azo dyes is overcome by heterocyclic azo dyes. 

Excellent yields of adduct have been obtained from a variety of o-quinones, including o-benzoquinone, 1,2-naphthaquinone, phen-anthraquinone, 5,6-chrysenequinone, and many of their simple derivatives, including the heterocyclic quinone 326 benzo[A]quinoline-5,6-quinone. Lower yields are in general observed for aromatic diketones such as benzil,327 and the reaction does not appear to occur to any appreciable extent with aliphatic a-diketones. 

Peri-annelated heterocyclic systems 411 with the inverse heteroatom orientation are formed on heating anthraquinone-1 -carboxylic acid 410 in aqueous solution of hydroxylamine hydrochloride (64MI1). 

The heterocycle formed in the cyclocondensation reactions of 2-acetylenyl-l-chloro-9,10-anthraquinones or 5-acet-yleneyl-3-(diethylamino)-l,4-naphthaquinones with hydrazine is influenced by the presence of a heterofunctional OH group in the acetylenic substituent. This directive effect was used in the synthesis of naphtha [2,3- ]cin noline-4,7,12-triones and 4//-naphtho[ 1,8-z/7]-l, 2-dia/cpin-8-oncs <2000MC188>. 

Anthraquinone dyes are characterized by the presence of one or more carbonyl groups in association with a conjugated system. These dyes also may contain hydroxy, amino, or sulfonic acid groups as well as complex heterocyclic systems. Anthraquinones uses include disperse, vat, acid, mordant, and fiber reactive applications. 

The two overriding trends in traditional colorants research for many years have been improved cost-effectiveness and increased technical excellence. Improved cost-effectiveness usually means replacing tinctorially weak dyes such as anthraquinones, until recently the second largest class after the azo dyes, with tinctorially stronger dyes such as heterocyclic azo dyes, triphendioxazines, and benzodifuranones. This theme will be pursued throughout this chapter, in which dyes are discussed by chemical structure. 

A large number of quinones of the general structure 7 are known, where X corresponds to a heterocyclic residue containing one or more rings, and the chemistry of these has been reviewed extensively [6-8], If X consists of a benzenoid or aza-benzenoid ring system, then such compounds are best regarded as anthraquinone analogues. In the case of other heterocyclic residues, they may be considered as 1,4-naphthoquinone derivatives. 

Heterocyclic analogues of anthraquinone are a family of potent antibiotics, many with antitumor and cytostatic properties. Diazaquinomycin A (118) is a thymidine synthetase inhibitor <88TL3545>. Low solubility of compound (118) has led to the development of more soluble active analogues, for example, (119) (92JPS815, 94EUP574195). 

Additional noteworthy applications of CEC include natural products such as the plant flavonoids hesperetin and hesperidin [160], anthraquinones extracted from rhubarb and from Chinese medicine [161], and heterocyclic compounds present in oils of bergamot, mandarin, and sweet orange [162], The CEC analysis of retinyl esters has been investigated by Roed et al. in nonaqueous mode for the separation of liver extracts of arctic seal [163]. Carotenoid isomers were also separated on C30 stationary phases by nonaqueous CEC [164]. It was found that CEC offered increased resolution compared to HPLC, and in CEC... 

Shvartsberg MS, Ivanchikova ID (2003) Synthesis of sulfur-containing heterocyclic compounds by cyclocondensation of acetylenic derivatives of anthraquinone with sodium sulfide. ARKIVOC 13 87-100... 

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