Anthraquinone alkylated

There is a wide variety of dyes unique to the field of hair coloring. Successive N-alkylation of the nitrophenylenediamines has an additive bathochromic effect on the visible absorption to the extent that violet-blue dyes can be formed. Since the simple A/-alkyl derivatives do not have good dyeing properties, patent activity has concentrated on the superior A/-hydroxyalkyl derivatives of nitrophenylenediamines (29,30), some of which have commercial use (31). Other substituents have been used (32). A series of patents also have been issued on substituted water-soluble azo and anthraquinone dyes bearing quaternary ammonium groups (33). 

SuIfona.tlon, Sulfonation is a common reaction with dialkyl sulfates, either by slow decomposition on heating with the release of SO or by attack at the sulfur end of the O—S bond (63). Reaction products are usually the dimethyl ether, methanol, sulfonic acid, and methyl sulfonates, corresponding to both routes. Reactive aromatics are commonly those with higher reactivity to electrophilic substitution at temperatures > 100° C. Tn phenylamine, diphenylmethylamine, anisole, and diphenyl ether exhibit ring sulfonation at 150—160°C, 140°C, 155—160°C, and 180—190°C, respectively, but diphenyl ketone and benzyl methyl ether do not react up to 190°C. Diphenyl amine methylates and then sulfonates. Catalysis of sulfonation of anthraquinone by dimethyl sulfate occurs with thaHium(III) oxide or mercury(II) oxide at 170°C. Alkyl interchange also gives sulfation. 

The development of the autoxidation of alkyl anthraquinones led to a rapid iacrease ia the production of H2O2 but a sharp decline in the importance of the electrolytic process. In 1991 the total North American, Western European, and Japanese capacity for H2O2 production was more than 870,000 t (77). No H2O2 was produced by the electrolytic peroxydisulfate process. The last plant using this process closed in 1983. 

Reagent for Epoxides e.g. trichothecene-mycotoxins [1 — 6] valepotriates [7,17] Olefins, acetylene derivatives [8] 4-Hydroxycumarin, anthraquinone [8] Alkylating agents [9-12] NOz... 

Lithiation of 3,5-dibromopyridine with IDA and subsequent reaction with electrophiles provide 4-alkyl-3,5-dibromopyridines in high yield <96TL(37)2565>. The synthesis of aza-anthraquinones 39 via metallation of the pyridine ring of 38 was reported by Epsztajn <96T(52)11025>. 

The alkaline hydrolysis of alkyl esters of anthraquinone-1- and -2-carboxylic acids [26] has also been studied (Gore et al., 1971). The rates of... 

Alkyl anthrahydroquinone/alkyl anthraquinone in situ process, 24 173 Alkylanthrahydroquinones, 14 43, 44 oxidation of, 14 50... 

Most of these products are azo or anthraquinone types, often with a localised quaternary ammonium group isolated from the chromogen by a saturated alkyl chain, as in Cl Basic Red 18 (1.52). Such products often exhibit higher light fastness than the traditional delocalised types. Improved azomethine, methine and polymethine basic dyes of good light fastness are also available. In contrast to the more specialised traditional classes, the azo and methine dyes have contributed to the basic dye range across the entire spectrum of hues (see Table 1.6) and now account for a clear majority of all basic dyes listed in the Colour Index. 

Derivatives of diaminoanthrarufin (3.77 X = Y = H) and its 1,8-dihydroxy-4,5-diamino isomer (diaminochrysazin) have been among the most widely used anthraquinone dyes for ester fibres. For example, methylation of diaminoanthrarufin gives Cl Disperse Blue 26, a mixture of several components. Study of the pure N-alkylated derivatives from the base confirmed that monosubstitution (3.77 X = H, Y = alkyl) gives mid-blue dyes with excellent dyeing properties and acceptable fastness on polyester, but the bis-alkyl dyes (3.77 X = Y = alkyl) are greener and inferior in application properties. Mixtures of the unsubstituted base with alkylated components, as obtained industrially, were especially advantageous for build-up to heavy depths, however [93]. 

In a related series of 1,2,4-trisubstituted anthraquinone compounds, the effectiveness of various polar and nonpolar substituents to improve on the low heat fastness of 2-amino-1,4-dihydroxyanthraquinone (3.184 R = H) was examined (Table 3.50). Short-chain alkyl groups (methyl, ethyl) and even the pyranylmethyl ether are relatively ineffective but hydroxyalkyl, cyclohexyl, benzyl and morpholinylethyl groups show moderate increases. Further improvement is given by phenyl, pyridylmethyl and morpholinylpropyl. Outstandingly effective, however, are the benzothiazolyl, dodecylphenyl and fluoro-methylphenyl groupings. 

The traditionally most important route to 1-aminoanthraquinone [1] proceeds via nucleophilic exchange of anthraquinone-1-sulfonic acid or 1-chloroanthraquinone with ammonia. Replacing ammonia by amines affords the corresponding alkyl or arylaminoanthraquinones. 

At present, its synthesis requires a sequential hydrogenation and subsequent oxidation of alkyl anthraquinone [248]. One of the main problems of this process is the high cost of the quinine solvent and the need for continuous anthraquinone replacement. The manufacturing process is also hindered by frequent storage and transport problems. In view of these obstacles, the development of a new synthetic method is of great interest from a commercial standpoint. 

As mentioned earlier, the reductive power of an anion radical can be increased considerably by photoexcitation in the visible part of the spectrum. This type of reaction has been demonstrated in the case of the photo-assisted reductive cleavage of alkyl halides in presence of anthraquinone as mediator Further work is necessary to evaluate the scope of this potentially important process. 

Aliphatic aldehydes and ketones and also aliphatic-aromatic ketones can be converted into the corresponding hydrocarbons alkyl-phenols can be obtained from phenolic-aldehydes and -ketones p-hydroxy-benzophenone yields p-benzylphenol benzoin and benzil yield dibenzyl anthraquinone yields anthracene dihydride. 

The alkylated anthraquinone process accounts for over 95% of the world production of H202, mainly because the it operates under mild conditions and direct contact of 02 and H2 is avoided. In this process, 2-alkylanthraquinone (the alkyl group is typically an ethyl, terf-butyl or amyl group) is dissolved in a mixture of a non-polar solvent (C9-Cn alkylbenzene) and a polar solvent [Trioctyl phosphate (TOP), or tetrabutyl urea (TBU) or diisobutyl carbinol (DIBC)] and then hydrogenated over a precious metal (Pd or Ni) catalyst in a three-phase reactor (trickle bed or slurry bubble column) under mild reaction conditions (<5bar, <80 °C) to generate 2-alkylanthrahydroquinone [1-3, 5], The latter is then auto-oxidized with air in a... 

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