Anthraquinone Anthrimide Carbazoles

Anthrimide Carbazoles. Fast vat dyes are produced by carbazole ring closure from a,a-dianthraquinonylamines (anthrimides). The shade is determined by the number and position of the carbazole systems and by additional substituents, especially acylamino or alkoxyl groups. Anthraquinone carbazoles make it possible to dye cellulose fibers in level, very fast yellow, orange, brown, gray, and olive shades. However, this series lacks dyes with bright shades. 

Various more complex dyes of industrial significance contain more than one carbazole system. For example, Cl Vat Orange 11 (6.86) contains two carbazole components and a central unit derived from 1,5-diaminoanthraquinone. This dye is prepared by carbazolisation of the trianthrimide produced when two moles of 1-chloroanthraquinone react with one mole of 1,5-diaminoanthraquinone. The equivalent isomeric dye obtained from 1,4-diamino-anthraquinone is reddish brown (6.87 Cl Vat Brown 1). The interesting, symmetrically-substituted tetracarbazole dye Cl Vat Green 8 (6.88) was first synthesised in 1911 by Hepp from 1,4,5,8-tetrachloroanthraquinone. Not surprisingly, the product (C70H28N4Oio relative molecular mass 1084) is of very low solubility. The structure was confirmed in 1957 by Jayaraman, who found no evidence of uncyclised anthrimides in the UV spectrum of the dye solution in concentrated sulphuric acid [32]. 

Other Acid Anthraquinone Dyes. In addition to the dyes in the preceding classes, a whole series of specially developed products is available. For instance, derivatives of the anthrimide or carbazole series are known to be very light-fast gray and brown wool dyes. The post-sulfonation products of 1,5- and 1,8-diarylami-noanthraquinones are violet dyes commonly applied as mixtures. 

A typical use of 61 is, by fusion with potassium hydroxide at high temperature, in the production of flavanthrone (67) (Scheme 15). Fusion of 61 with potassium hydroxide under milder conditions affords the important anthraquinone azines known as indanthrones (Travis Chapter 1). The main vat-dye reactions proceed via anthrimides, which are both dyes and intermediates, since they are readily converted into cyclic carbazole derivatives. For example, benzanthrones, such as 68 and 69, dibenzanthrones, isodibenzanthrones, and their derivatives and substitution products, are important in vat-dye manufacture. An example of their use is in the synthesis of Cl Vat Olive T (70) (Scheme 16). Benzanthrone acridones made from 1-aminoanthraquinones are important green dyes. Certain vat-dye reactions require high-boiling organic solvents. 

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See also in sourсe #XX -- [ ]

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