CS240795B1 - Method of diaminodihydroxy anthraquinone treatment - Google Patents

Abstract

Process for the preparation of diaminohydroxyanthraquinones of the general formula, (51) Int. Clj C 07 C 97/26, C 09 B 1/50 where R is hydrogen or a sulfo group, by reduction of the corresponding dinitro compounds in an alkaline medium at elevated temperature with a mixture of reducing sugars in a molar ratio of glucose equivalent to each reducing nitro group of 1.2 to 2.0 : 1.

Description

The invention relates to a process for the preparation of diaminodihydroxyantraquinones by reduction of the corresponding dinitrodihydroxyantraquinones.

The anthraquinone series nitro compounds are usually reduced to the corresponding amino compounds by treatment with sodium sulfide or other sulfides such as ammonium sulfide, acidic sodium sulfide or polysulfides. Thus, at elevated temperature, a series of dinitrodihydroxyantraquinones can be reduced to the corresponding diaminodihydroxyantraquinones, important intermediates for dispersion production. dyes of blue shades, sulphides are inexpensive reducing agents, but their use on a large scale, however, poses a significant risk of releasing toxic hydrogen sulphide in contact with mineral acids, therefore working with sulphides requires perfect safety precautions starting from handling this substance and ending with disposal waste water from the reaction, which must not come into contact with other acidic waste water. Working with otherwise cheap sulphides becomes more expensive and it is an effort to replace them with other reducing agents,

The reduction of some diaminodihydroxyantraquinones with glucose or inverted saccharide in the alkaline environment of the phenol-water environment has also been described in the literature,

In an alkaline environment, the reduction proceeds satisfactorily in terms of the conversion of the starting dinitroate and the yield of the diamine, but the cost of crystalline glucose makes it economically unattractive. The use of cheaper sucrose in the chemical industry is limited by the fact that it is a foodstuff. In a phenol-water environment, glucose is reduced in

4,5-dinitro-1,8-dihydroxyamtraquinone with only 1 nitro group, to give 4'-amino-5-nitro-1,8-dihydroxyantraquinone.

It has now been found that the diamino-dihydroxyantraquinones of formula I,

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where R is hydrogen or sulfo, the corresponding diaminodihydroxyantraquinones of formula II ₍

wherein R is as defined above, reduced with very good yield and economically advantageously with various reducing sugar mixtures.

These can be obtained either. as waste from certain food or chemical industries, or may be prepared from natural polysaccharide-containing materials for reduction purposes.

Among the useful chemical wastes used for the reduction of the dinitrodihydroxyantraquinones of the formula I, mention may be made of distillation residues from pentaerythritel production containing a mixture of pentos and hexos and harmless pentaerythritol and calcium formate for the reduction process, or waste from beech wood to viscose.

This waste again contains a mixture of reducing pentoses and hexoses and harmless amounts of furfural, acetic acid, formic acid and lignins for reduction. The concentration of distillery stillage, which is the residue from the production of fermented ethanol from molasses, can likewise be used.

Of the food product wastes, the mother filtrates may be advantageously used as reducing agents for the crystallization of glucose produced by acid hydrolysis of starch. These filtrates contain glucose as the main constituent and, in addition, other reducing monosaccharides, such as levoglucosan, xylose and arabinose, further reducing disaccharides such as maltose,

Similarly, molasses containing mainly glucose and sucrose can be used, and the reducing effect of molasses can be further enhanced by inverting the present sucrose. Other abrasive wastes include thickened liquid pectin isolation wastes containing a mixture of inorganic substances, reducing sugars and optionally other substances (such as citric acid). Similarly, concentrated waste water from yeast production can be used.

A mixture of reducing monosaccharides, disaccharides and other oligosaccharides can also be prepared by acid or enzymatic hydrolysis of starch or starch-containing substances, such as various types of flour, where flour which is not suitable for food or feed purposes can be advantageously used. Acidic hydrolysis of the isolated starch or starch contained in the flour produces a mixture of monosaccharides, disaccharides and other oligosaccharides, containing predominantly glucose, maltose, isomaltose, minor amounts of xylose and aratoinosine, and other substances such as glycosides formed by reaction of monosaccharides glucose products such as jakoyk, 5-hydroxyraethylfurfural, levulic acid and formic acid.

These substances are not a defect in the reduction of dinitrodihydroxyantraquinones. When starch is degraded to reducing sugars enzymatically by amylase, the resulting reducing sugar solution is rich in glucose. In the case where the acid flour hydrolyzate is used after the reduction, the insoluble protein must first be removed from the suspension after the hydrolysis.

The reducing ability of a solution mixture of reducing sugar it is advantageous to express a glucose equivalent t.zv _e, which is determined by conventional methods e.g. · Luff-Schoorl ·

If the reducing sugar solutions are not sufficiently resistant to ethanolic fermentation, they can be preserved during storage by adding, for example, potassium pyrosulfite, sodium sulfite, formic acid, formaldehyde, or biocidal agents such as bis (tributyltin) oxide.

Of the dinitrodihydroxyantraquinones of the formula I, the following substances may in particular be used:

4,8-dinitro-1,5-dihydroxyantraquinone or a mixture thereof with 2,4-dinitrophenol as obtained by alkaline hydrolysis

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4,8-dinitro-1,5-bis (2,4-dinitrophenoxy) anthraquinone 4,5-dinitro-1,8-dihydroxyantraquinone or a mixture thereof with 2,4-dinitrophenoler as obtained by alkaline hydrolysis of 4,5-dinitro -1,8-bis /

2,4- dinitrophenoxy / anthraquinone

Mixture of 4,8-dinitro-1,5-dihydroxyantraquinone with 4,5-dinitro-1,8-dihydroxyantraquinone or a mixture of the two and 2,4-dinitrophenol after alkaline hydrolysis of the corresponding 2,4-dinitrophenoxy derivatives

4.7-dinitro-1,8-dihydroxyantraquinone

4,5-dinitro-1,8-dihydroxyantraquinone or a mixture of the two latter

4,8-dinitro-4,5-dihydroxyantraquinone-2,6-disulfonic acid

4,5-dinitro-1,8-dihydroxyantraquinone-2,7-disulonic acid

Said dinitrodihydroxyantraquinones may be reduced by a mixture of reducing sugars in an aqueous-alkaline medium at a temperature of 80 to 100 ° C, the amount of reducing solution being applied such that 1.2 to 2.0 moles of glucose equivalent per reducing nitro group. After completion of the reduction, the resulting diaminodihydroxyantraquinones are filtered off and washed with water until neutral.

In the case of diaminodihydroxyantraquinone sulfonic acids, the reaction mixture is first salted out after reduction, the precipitate is filtered and washed with dilute sodium chloride solution until neutral. The mother filtrates and washings contain carbohydrate oxidation and decomposition products such as gluconic, lactic, oxalic and formic acids and their disposal does not require any special measures.

The following examples illustrate the reduction process of the invention. The parts indicated are those of IVt tnestat. for solids and by volume for liquids.

Example 1

114 parts of a neutral aqueous paste containing 29% 4,5-dinitro-1,8-dihydroxyantraquinone, i.e. 33.0 parts of 100% of the substance are mixed in 600 parts of water, a solution of 30 parts of 95% sodium hydroxide in 60 parts of water is added. the mixture is heated to 95 ° C _e is then evenly added to 138 parts of the mother filtrate from the crystallization of glucose (made by hydrolysis of starch using acid), which corre- 5,240,795 gives 50.4 parts of glucose equivalents ₉ the reduction is even a further

Heating for 1.5 hours at 95 ° C. The reaction mixture is then allowed to cool to 60 ° C, the precipitated fine crystalline product is filtered off and the cake is washed with 60 ° C warm water until neutral to brilliant yellow and to a colorless filtrate. Drying the product paste at 90 ° C yields 26.9 parts of the technical diaminodihydroxylate it contains

89.2% of 4,5-diamino-1,8-dihydroxyantraquinone, i.e. 24 parts of 100 substance i.e. 89% th.

Example 2

68.7 parts aqueous paste containing 33.7% 4,5-dinitro-1,8-bis)

The 2,4-dinitrophenoxy / anthraquinone, i.e., 23.17 parts of 100% of the compound, is stirred in 250 parts of water and a solution of 9 parts of 95% sodium hydroxide in 15 parts of water is added to the fine suspension. The reaction mixture is heated to 95 ° C and maintained at this temperature for about 1 hour. During this time, the hydrolyzed and nitrated phenoxy group is run, the end of which is controlled by thin-layer chromatography. A solution of 10 parts of 95% sodium hydroxide in 25 parts of water is added to the reaction mixture after hydrolysis, and a solution of reducing sugars in the form of concentrated pectin-containing wastes containing 36 parts of glucose equivalent is gradually added at 95 °. At the beginning of introduction of the reducing agent, the reaction proceeds mildly exothermic and the temperature maintained at 95 C. ^{At the} speed control is added to the reducing agent. After addition of the reducing agent, the reaction mixture was kept 0.5 hours at 95 ° C and then allowed to cool to _about 55 ° C At this temperature, the precipitated microcrystalline share filtered and washed with 60 ° C warm water to neutrality and the colorless filtrate. Drying of the paste at 95 ° C gives 8.62 parts of a dark blue product containing 85% 4,5-diaraino-1,8-dihydroxyantraquinone, ie 7.3 g of 100%, ie 77% th. based on the starting 4,5-dinitro-1,8bis (2,4-dinitrophenoxy) anthraquinor. If the same starting nitro compound is reduced by sodium sulfide or glucose according to a generally known procedure, the ad at the same batch in the first case in the first case obtains 7.3 parts of 100% diaminodihydroxyantraquinone, i.e. 77% th. and in the second case 7.0 parts of a 100% diaminodihydroxy derivative ie 74% th. relative to the starting nitro compound. In the chromatographic comparison of the two compounds with the diaminodihydroxyantraquinone prepared according to Example 2, virtually no differences were observed.

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Hydrolysis and reduction of 4,8-dinitro-1,5-bis (2,4-dinitrophenoxy) anthraquinone can be carried out in the same manner.

Example 3

68.7 parts of an aqueous paste containing 23.17 parts of 4,5-dinitro-1,8-bis (2,4-dinitrophenoxy) anthraquinone are hydrolyzed and reduced according to the procedure of Example 2, except that 150 parts of a reducing carbohydrate solution obtained by acid hydrolysis of wheat flour containing 36 parts of glucose equivalent. Filtration of the reaction mixture, washing of the cake and drying yielded 8.38 g of a dry product containing 85%

4,5-diamino-1,8-dihydroxyantraquinone, i.e. 7.1 g of 100% i.e. 75.3% th. to the starting nitro compound. Acidic hydrolyses and flours are carried out, for example, as follows:

110 parts of water and 2.1 parts of HCl 36% are heated to gentle boiling and 72 parts of flour are introduced in 1 hour. The suspension is then heated to gentle boiling for 8 hours. Insoluble proteins are filtered off after the addition of a filtering agent, which may be, for example, wood flour. The filtrate contains a mixture of reducing sugars with a content of 36 parts glucose equivalent.

Example 4

68.7 parts of an aqueous paste containing 23.17 parts of 4,5-dinitro-1,8bis (2,4-dinitrophenoxy) anthraquinone is hydrolyzed and reduced according to the procedure of Example 2 except that a concentrated waste from processing of beech wood into a viscose containing reducing sugars corresponding to 44 parts glucose equivalent. Filtration of the reaction mixture, washing of the cake and drying yields a technical product which contains 6.9 parts of 4,5-diamino-1,8-dihydroxyantraquinone, i.e. 73% th. to the starting nitro compound.

Example 5

Sodium 53,4-part of 4-8-dinitro-1,5-dihydroxyantraquinone-2,6-disulfonate in the form of a 34% aqueous, slightly acid paste is stirred in 800 parts of water and the resulting suspension is neutralized with a 40% sodium hydroxide solution to pH 7 »5 to 8. To the reaction mixture is added a solution of 95% sodium hydroxide in 200 parts of water, the mixture is heated to 95 ° C and 210 parts of hydrolyzate are added dropwise over about 15 minutes.

7 240 795 flour, prepared according to Example 3, containing 4θ, 4 parts glucose equivalent. After introduction of the hydrolyzate, the reaction mixture is maintained at 95 ° C for about 0.5 hours until the reduction is complete. The end of the reaction was monitored by thin-layer chromatography. If no starting nitro compound or hydroxy amino derivatives are present in the mixture, the reaction mixture is salted out at 85 ° C with 30 parts of anhydrous sodium sulphate and the product precipitated after cooling to 35 ° C is filtered and washed with a 1.5% sodium sulphate solution to neutrality on brilliant yellow. Dry the cake at 85 ° 0 to const. 36.2 parts by weight of the reduced product, which contains predominantly sodium 4,8-diamino-1,5-dihydroxyantraquinone-2,6-disulfonate, were evaluated in color shade with a slightly greener, slightly brighter shade and in strength 50/100 Location hydroly.átu flour can be used with the same results also in a reduction of filtrate after crystallization of glucose, prepared by enzymatic hydrolysis of starch ou _e above procedure can also successfully reduce the 4,5-dinitro-l, 8--dihydroxyantraquinone Sodium -2,6-disulfonate.

Claims (1)

A process for the preparation of diaminodihydroxyantraquinones of the formula wherein R is hydrogen or sulfo by reducing the corresponding dinitro compounds in an alkaline environment at elevated temperature and in the presence of reducing sugars, characterized in that a mixture of monosaccharides and oligosaccharides in solution is added to the reaction mixture in molar ratio of glucose equivalent to each reducing nitro group of 1.2 to 2.0: 1.