Benzanthrone derivatives

Benzanthrone Dyes. Vat dyes derived from benzanthrone may be divided into two groups violanthrones and isoviolanthrones, dyes that have the perylene ring in their molecular stmcture and benzanthrone pyrazolanthrones and benzanthrone acridones, the peri ring closure products of 3-anthra quin onyl amino-ben zanthrone. 

Benzanthrone has been prepared by three general methods, the first of which is generally regarded as the best (i) by heating a reduction product of anthraquinone with sulfuric acid and glycerol,1 or with a derivative of glycerol, or with acrolein. The anthraquinone is usually reduced in sulfuric acid solution, just prior to the reaction, by means of aniline sulfate, iron, , or copper. It has also been prepared (2) by the action of aluminum or ferric chloride on phenyl-a-naphthyl ketone, and (3) from i-phenylnaphthalene-2-carboxylic acid. ... 

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]. 

Isoviolanthrone (109) is an highly anellated polycyclic quinone system. It is derived from the chemical structure of isodibenzanthrone, which may be visualized as being obtained by unsymmetrical condensation of two benzanthrone molecules. The compound itself affords an intense blue shade. 

As an example, we saw earlier, replacing the CH2 group in the parent PAH 7//-benz[de]anthracene, XII, by a keto group, C=0, gives 7//-benz[de]anthracen-7-one, XIII (benzanthrone). It is well known as a major O-PAC in combustion-generated emissions and ambient air (see Table 10.4) and the 3-nitro derivative,... 

Chemists at the rival Bayer company established the structure Indanthrone consists of two anthraquinone units joined through a heterocyclic bridge containing two nitrogens. This enabled industrial research laboratories to discover anthraquinone-based intermediates for other vat dyes. In 1904, an assistant of Bohn synthesized benzanthrone (48), later an important intermediate in processes involving aminoanthraquinone-derived colorants72. 

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. 

Bally-Scholl synthesis. Formation of meso-benzanthrones by the action of glycerol or a derivative, and sulfuric acid on anthraquinones or an-thranols. 

Derivation From benzanthrone by treatment with chlorine. 

The formation of ketonic and quinonoid derivatives of aromatic hydrocarbons during combustion (Alsberg et al. 1985 Levsen 1988). The environmental distribution of benzanthrone and related compounds such as benzo c,d ] py rene-6-one and cyclo pen ta dtf phenan-threne-4-one has been reviewed (Spitzer and Takeuchi 1995), and such transformation products have been identified in, for example, marine sediment samples (Fernandez et al. 1992), fish from a contaminated river (Vassilaros et al. 1982), and urban aerosols (Galceran et al. 1995 Allen et al. 1997). 

Isoviolanthrone is described as a highly anellated polycyclic quinone system , essentially two benzanthrone molecules joined asymmetrically. This compound was first synthesised in 1907 and has long been known as a vat dye. However, it is the dichloro-derivative which is best known as a pigment, affording the reddish violet colour known as isoviolanthrone violet. Cl Pigment Violet 31 Colour Index, 1971 Wich, 1973 Herbst and Hunger, 1997). 

Benzanthrone likewise combined with Grignard rei ents both Clar (14) and Nikanishi (15) believed that they had brought about 1,6-addition. Charrier and Ghigi showed, however, that the reaction was of the l,4-t5rpe. With the methyl and ethyl reagents the corresponding 4-alkyl derivatives of benzanthrone were obtained (16). 

Condensation, In a restricted sense, condensation describes those reactions in which a carbon-carbon bond is formed by the elimination of a simple molecule. An example is the condensation of benzanthrone to dibenzanthrone, shown below in Fig. 23.6 and described on page 909. Dye intermediate chemical terminology uses the term condensation more broadly than this to describe a variety of reactions in which molecules are joined the bonds formed are not restricted to carbon-carbon. An example is the formation of the diphenylamine derivative, commonly called Nitro Delta Acid ... 

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