JPH0730475B2 - Method for producing 1-aminoanthraquinones - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a method for producing 1-aminoanthraquinones. More specifically, the following general formula (A)
1-nitroanthraquinones represented by
Electrolytic reduction is performed in the presence of a basic compound, and at least a part of 1-nitroanthraquinones is electrolytically reduced to a hydroquinone form of 1-aminoanthraquinones represented by the general formula (C), and then the 1-aminoanthraquinones are produced. Of 1-aminoanthraquinones represented by the following general formula (B), which oxidizes the hydroquinone compound of (In the above formulas (A), (B) and (C), R ¹ and R ² each independently represent one selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms and a halogen atom. .) It relates to a manufacturing method.

1-Aminoanthraquinones are compounds having a wide range of uses as intermediates for dyes and pigments.
-Aminoanthraquinone is known as an industrially important intermediate compound.

[Prior Art] In a method for producing 1-aminoanthraquinone by reducing 1-nitroanthraquinones, as a conventional reduction method, a method of hydrogenating reduction using a hydrogenation catalyst (Japanese Patent Publication No.
55-17023), or a method of reducing with alkali sulfide or alkali hydrosulfide (JP-A-53-44550). However, the method of hydrogenation reduction using a hydrogenation catalyst involves various side reactions, the yield is low, and the separation of the catalyst and the product is not easy, which is a problem. On the other hand, in the method of reducing with alkali sulfide or alkali hydrosulfide, the amount of alkali sulfide or alkali hydrosulfide used is large, the COD in the waste liquid becomes high, and its treatment becomes a big problem.

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned drawbacks that cannot be solved by the conventional methods, to perform a selective reaction under mild reaction conditions, and to perform product separation and wastewater treatment. An object of the present invention is to provide a method for obtaining 1-aminoanthraquinones from 1-nitroanthraquinones that is easy and industrially advantageous in terms of working environment and pollution.

[Means for Solving the Problems] The present inventors finally conducted the present invention as a result of earnestly researching to develop a method for industrially advantageously producing 1-aminoanthraquinones. That is, according to the present invention, 1-nitroanthraquinone represented by the general formula (A) is electrolytically reduced in an aqueous solvent in the presence of a basic compound, and at least a part of the 1-nitroanthraquinone is represented by the general formula ( 1-aminoanthraquinone represented by the general formula (B), which is characterized in that the 1-aminoanthraquinone represented by C) is electrolytically reduced to a hydroquinone body, and then the 1-aminoanthraquinone hydroquinone body is oxidized. A method of manufacturing the same is provided.

According to the method of the present invention, the target 1-aminoanthraquinone is obtained in high yield under a simple operation and mild reaction conditions.
It can be obtained with high purity and at low cost without causing problems of product separation or environmental damage. The details will be described below.

The 1-nitroanthraquinones used as a starting material can be obtained, for example, by nitrating anthraquinones with nitric acid or a mixed acid of nitric acid and sulfuric acid.

In the present invention, 1-nitroanthraquinones are electrolytically reduced in an aqueous solvent in the presence of a basic compound. By such a method, intermediates such as 1-hydroxylaminoanthraquinones and hydroquinone compounds of the general formula (C) which are formed on the way to 1-aminoanthraquinones are well dissolved in an aqueous solvent, so that unreacted raw materials 1- Since it is easy to separate from nitroanthraquinones and basic compounds are well dissolved in an aqueous solvent, electroconductivity is increased, electrolysis voltage is reduced, current efficiency is improved, and other electrolytic characteristics are improved.

The aqueous solvent is preferably water or an aqueous solution of a hydrophilic organic solvent such as alcohols such as methanol, ethanol, isopropanol and ethylene glycol, ethers, especially cellosolves such as methyl cellosolve, ketones such as acetone, and the like. Alternatively, they can be mixed and used, and an electrolyte may be added to the solvent in order to increase the conductivity. Further, when a non-aqueous solvent is used together with an aqueous solvent, the unreacted raw material is dissolved in the non-aqueous solvent phase and the product after electrolytic reduction is dissolved in the aqueous solvent phase to facilitate separation.

As the basic compound to be present in the electrolytic reduction of the present invention, a usual inorganic or organic basic compound can be used, and specific examples include the following.

1) Periodic Table Group Ia, Group Ib, Group IIa and Group IIb metal oxides, hydroxides and salts with weak acids (eg magnesium oxide, calcium oxide, sodium hydroxide,
Potassium hydroxide, sodium bicarbonate, sodium carbonate,
Sodium acetate, sodium borate, sodium sulfite, sodium phosphate-hydrogen phosphate, potassium phosphate, potassium permanganate, sodium chromate, sodium sulfide, sodium methylate, sodium phenolate,
Ethylenediaminetetraacetic acid tetrasodium, sodium polysulfide, sodium hydrosulfide, etc.) 2) Ammonia, ammonium carbonate and ammonia complex salt 3) Primary amine, secondary amine, tertiary amine, quaternary amine hydroxide and other Nitrogen-containing basic compounds Among these, particularly, the hydroxides, carbonates, and bicarbonates of metals of Group Ia, Group Ib, Group IIa, and Group IIb of the periodic table are remarkable, and are suitable. Used. The amount of the basic compound to be present during the electrolytic reduction may be an amount that can be maintained basic, particularly as a basic compound Group Ia, Group IIa, Group Ib, Group Ib metal of the periodic table If the basic compound of 1 is used in an amount of 2 equivalents or more with respect to 1-nitroanthraquinones, it is easy to handle because it is dissolved as a hydroquinone salt of 1-aminoanthraquinones after completion of electrolytic reduction under a reducing condition, which is preferable. Further, if the amount of the basic compound is too large, the selectivity in electrolytic reduction decreases, so it is preferably 1000 equivalent times or less with respect to 1-aminoanthraquinones.

The electrolytic reduction may be carried out in the state of an electrolytic solution in which 1-nitroanthraquinones are completely dissolved, but it can also be carried out in an emulsion or slurry state, and in the state of slurry for the purpose of increasing the concentration of raw materials and increasing productivity. Preferably there is. When the interfacial tension of the electrolytic solution is large, foaming may occur, but in order to suppress this, it is also effective to add, for example, a silicon antifoaming agent to the electrolytic solution.

The concentration of the 1-nitroanthraquinones in the catholyte during the electrolytic reduction is not particularly limited, but if it is too low, the electrolytic properties such as current efficiency deteriorate, and if it is too high, the viscosity of the liquid increases. Therefore, the concentration of 1-nitroanthraquinones in the catholyte is 0.01 to 50% by weight, more preferably 0.1 to 20% by weight.
It is desirable to be in the range of.

The electrolytic reduction is preferably carried out in an electrolytic cell comprising an anode chamber and a cathode chamber having a diaphragm in the center. When the diaphragm is not used, the structure of the electrolytic cell is simplified, the cost related to the electrolytic cell and the maintenance are facilitated, and there is an advantage that there is no need to oxidize after the electrolysis because an oxidation reaction occurs at the anode. However, when the diaphragm is not used, in addition to mixing of the anolyte and catholyte, the products produced by reduction in the cathodic reaction and the raw materials move to the anode side and are oxidized to produce by-products, It causes a decrease in current efficiency, selectivity or yield. Any membrane can be used as the diaphragm as long as it has a role of preventing the mixing of the bipolar liquids, and an ion exchange membrane, a porous ceramic, a resin or the like can be used. An anion exchange membrane or a cation exchange membrane is used as the ion exchange membrane, and a fluorine-based ion exchange membrane is preferable in consideration of durability.

In the electrolytic reduction, a known electrode is usually used as the cathode material, but when an aqueous solvent is used as the catholyte, it is preferable to use a material having a large hydrogen overvoltage in order to avoid a decrease in current efficiency due to hydrogen gas generation. It is also effective to use a component having catalytic activity for the hydrogenation reaction. Specifically, palladium, platinum, ruthenium, rhodium, nickel, cobalt, copper, lead, iron, zirconium, cadmium, silver, tin, zinc, mercury, titanium, stainless steel, graphite, etc. are used alone or in combination of two or more kinds. To be
They can also be supported on the substrate in the form of alloys, compounds, plating, sintering and the like. On the other hand, a known electrode material is used for the anode, and for example, oxide-coated electrodes such as iridium oxide-coated titanium and platinum-iridium oxide-coated titanium, platinum-plated titanium, graphite and glassy carbon are used.

The electrolytic reduction can be performed by either the constant voltage method or the constant current method, but the constant current method is preferable. Electrolytic current density is usually 1-250 m
A / cm ² , preferably 10 to 150 mA / cm ² . The electrolysis temperature is not particularly limited, but if it is low, the electrolysis voltage will rise and the viscosity of the electrolyte will also rise, so it is preferably 5 ° C or higher, and if the temperature is too high, it will cause corrosion of the material and decrease in selectivity and yield, so it is 180 ° C or lower. Is preferred. More preferably, it is in the range of 30 to 120 ° C.

Even if a diaphragm is used, electrolytic reduction is preferably performed in a non-oxidizing atmosphere because oxygen is likely to be generated in the anode and an oxidizing atmosphere is easily generated. The anolyte is not particularly limited as long as it is an electrolytic solution, but when electrolyzing using an electrolytic cell having a diaphragm, a 1-aminoanthraquinone having a large crystal grain size is obtained by using a proton donating solution such as an acid as the anolyte. It is preferable because the 1-aminoanthraquinones can be easily separated by filtration or the like, the concentration of the basic compound in the filtrate does not increase, and the filtrate can be reused. Examples of the proton-donating solution include carboxylic acids such as acetic acid and trifluoroacetic acid; phenols;
Alcohols such as butanol, propanol, ethanol, methanol; glycols such as ethylene glycol; sulfonic acids such as methanesulfonic acid and trifluoromethanesulfonic acid; inorganic acids such as phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid;
There is water or the like, and a mixture thereof may be used. Particularly, an acid or an aqueous acid solution is preferable, and an aqueous solution of one selected from phosphoric acid, methanesulfonic acid, hydrochloric acid, nitric acid and sulfuric acid is more preferable.

There is also a method of performing electrolytic reduction while externally circulating the electrolytic solution, but after electrolytically reducing the electrolytic solution in a batch system by charging the electrolytic solution in the electrolytic cell, a method of extracting the electrolytic solution, or the electrolytic solution in the electrolytic cell A method of continuously circulating in one pass to carry out electrolytic reduction is preferable. In the case of these methods, a product having improved conversion, high purity and large particle size can be obtained. In addition, since the catholyte is foamed during electrolytic reduction to increase the electrolytic cell volume, the viscosity of the catholyte increases due to the reaction and the workability deteriorates, and the raw material concentration in the catholyte is lowered to prevent these. However, when the latter method is used, the problems of increasing the viscosity of the catholyte and foaming during electrolytic reduction do not occur, and the concentration of the raw material in the catholyte is reduced. It is possible to increase the productivity and further improve the productivity.

At the time of electrolytic reduction, it is also possible to carry out an oxygen generation reaction or another effective anodic reaction at the anode. For example, when hydrochloric acid is used as the anolyte, chlorine gas can be obtained by the anodic reaction, and the anodic reaction can be effectively used. As an electrolytic cell used for electrolytic reduction, a known electrolytic cell such as a tube type, a tank type and a filter press type is used. Further, when electrolytic reduction is performed under a pressure of 0.1 to 25 kg / cm ² G, even if hydrogen is generated at the cathode, it dissolves in the catholyte and effectively acts as a reducing agent to improve current efficiency. Further, it is effective against foaming of the catholyte during electrolysis, the raw material concentration in the catholyte can be increased, and electrolytic reduction can be advantageously performed.

In electrolytic reduction, when the 1-nitroanthraquinones are two-electron reductively hydrogenated to directly obtain 1-aminoanthraquinones, it is difficult to increase the conversion rate of the raw material. On the other hand, in the case of 4-electron reductive hydrogenation of 1-nitroanthraquinones, a hydroquinone form of 1-aminoanthraquinones is obtained, and then the 1-aminoanthraquinones can be easily obtained by oxidizing the hydroquinone form. In particular, when the hydroquinone group forms a salt and dissolves under a basic condition such as a hydroquinone form of 1-aminoanthraquinone, electrolytic reduction can be performed in a solution state and the operation is facilitated, which is preferable. To obtain 1-aminoanthraquinones from the hydroquinone form of 1-aminoanthraquinones, it is not necessary to use a special oxidizing agent, and they can be easily obtained by a simple operation such as oxidation through air or using hydrogen peroxide.

1-Aminoanthraquinones produced by electrolytic reduction or oxidation of hydroquinone form can be isolated by filtration, centrifugation, etc., and can be made into a sufficiently high-quality product by simply performing appropriate treatments such as washing and drying. .
The basic compound can be recovered together with the filtrate and recycled for electrolytic reduction. In this case, it is preferable to remove unnecessary organic compounds contained in the filtrate to prevent unnecessary reactions and reduction in product purity. This is carried out, for example, by passing the filtrate through an adsorption tower filled with an adsorbent such as activated carbon. If the filtrate is not recovered and reused for circulation, not only the amount of the aqueous solvent and the basic compound used becomes large, but also since these become waste liquids, the treatment thereof is required, which makes it difficult to carry out on an industrial scale.

[Examples] Next, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

Example 1 12 parts of 1-nitroanthraquinone was added to 50 parts of methyl cellosolve, 200 parts of 5% potassium hydroxide solution was further added, and the resulting slurry liquid was stirred to obtain an electrolytic cell separated by a porous ceramic diaphragm. 5% in the cathode chamber and in the anode chamber
200 parts of a sulfuric acid aqueous solution was added. A platinum-plated titanium electrode was used as the anode, and a nickel plate was used as the cathode.
During the electrolysis, constant current electrolysis was performed at 85 ° C. with a current density of 15 mA / cm ² while stirring the catholyte, and the electrolysis was terminated when an electric quantity of 12 faradaic was applied to 1 mol of 1-nitroanthraquinone used.

The catholyte was taken out and passed through air for 1 hour, and then the precipitate was filtered using a filter paper having a particle retention capacity of 8 microns. The filterability was good. The obtained precipitate was washed with water and dried, and the yield of 1-aminoanthraquinone in terms of purity was 99.2%.

Example 2 The electrolytic reduction was carried out in the same manner as in Example 1 using as a catholyte a solution 95 obtained by subjecting the filtrate obtained in Example 1 to adsorption treatment with activated carbon, to which 11.4 parts of 1-nitroanthraquinone was added. After the completion of electrolysis, the same operation as in Example 1 was performed to obtain 1-aminoanthraquinone with a purity-converted yield of 1-aminoanthraquinone of 99.0%.

Example 3 10 parts of 1-nitroanthraquinone having a purity of 98.2% was added to 50 parts of methanol, and 100 parts of a 5% sodium hydroxide solution was added to obtain a catholyte. 10% sulfuric acid aqueous solution was used as the anolyte, and 30 mA / cm ² at 40 ° C with a fluorine ion exchange membrane as the diaphragm.
An electric quantity of 16 F / mol was applied at a current density of. As for the electrode, a stainless steel plate was used for the anode, and a palladium-supporting carbon electrode was used for the cathode. After completion of electrolysis, the same operation as in Example 1 was performed to obtain 1-aminoanthraquinone (purity 99.4%) with a purity-converted yield of 98.5%. The filterability was good.

Example 4 The electrolytic reduction was carried out in the same manner as in Example 3 using as a catholyte a mixture of 95 parts of a solution obtained by subjecting the filtrate obtained in Example 3 to adsorption of activated carbon to 11.4 parts of 1-nitroanthraquinone. . After the completion of electrolysis, the same operation as in Example 1 was performed to obtain 1-aminoanthraquinone with a purity-converted yield of 1-aminoanthraquinone of 99.0%.

Example 5 A platinum-plated titanium electrode was used as the cathode, and the current density was 50.
Electrolysis was performed in the same manner as in Example 1 at mA / cm ² . When electricity of 16 F / mol was applied, a part of the catholyte was extracted using a pump and the supply of catholyte before electrolysis was started. In order to keep the amount of electrolytic solution in the electrolytic cell constant, the supply rate and the withdrawal rate were kept constant. The supply and withdrawal rates of the catholyte were set in consideration of the residence time in the electrolytic cell so that an electric quantity of 16 F / mol was applied to 1-nitroanthraquinone in the supply. The extracted liquid thus obtained was subjected to air oxidation and then filtered. The filterability was extremely good, and the recovered filtrate was reused for adjusting the catholyte supplied to the electrolytic cell. The 1-aminoanthraquinone obtained from the liquid extracted after the electrolytic cell was in a steady state was 99.1% in terms of purity based on the supplied 1-nitroanthraquinone.

Example 6 1-Aminoanthraquinone having a purity of 95.4% was obtained by performing the same operation as in Example 3 except that 1-nitroanthraquinone having a purity of 85% obtained by nitration of anthraquinone was used as a raw material.

[Effects of the Present Invention] As described above, the method of the present invention produces less waste than the conventional methods, and industrially advantageously produces 1-aminoanthraquinones in terms of pollution and production costs. It can be manufactured. Surprisingly, according to the method of the present invention, highly pure 1-aminoanthraquinone was obtained even when the crude 1-nitroanthraquinone obtained by nitration of anthraquinone was used as a raw material. The reason for this is not clear, but in the method of the present invention, the properties of 1-aminoanthraquinone and other impurities or byproducts, such as solubility, are different,
This is probably because the effect of purification has also appeared.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Inoue, 992, Nishi-oki, Kinohama, Aboshi-ku, Himeji City, Hyogo Prefecture 1 Susumu Ogawa, Catalytic Research Laboratory, Nippon Catalysis & Chemical Industry Co., Ltd. (56) Reference JP-A-2-262543 (JP, A) JP-A-2-311445 (JP, A)

Claims (9)

[Claims] 1. A general formula (A) (In the above formula, R ¹ and R ² each independently represent one selected from a hydrogen atom, an alkyl group having 1 to 4 carbon atoms and a halogen atom.) 1-nitroanthraquinone In an aqueous solvent,
General formula (B) for electrolytic reduction in the presence of a basic compound (In the above formula, R ¹ and R ² are the same as above.) In the method for producing a 1-aminoanthraquinone represented by the formula, at least a part of the 1-nitroanthraquinone of the formula (A) is represented by the general formula (C ) (In the above formula, R ¹ and R ² are the same as defined in claim (1).) The 1-aminoanthraquinone hydroquinone compound represented by the formula (1) is electrolytically reduced, and then the 1-aminoanthraquinone A method for producing a 1-aminoanthraquinone represented by the formula (B), which comprises oxidizing a hydroquinone body. 2. The basic compound is a group Ia group, a group Ib group of the periodic table,
The method according to claim 1, which is a basic compound of a Group IIa or Group IIb metal element. 3. The method according to claim 1 or 2, wherein the electrolytic reduction temperature is in the range of 30 to 120 ° C. 4. The method according to any one of claims 1 to 3, wherein the electrolytic reduction is carried out using an electrolytic cell having a diaphragm. 5. The method according to claim 4, wherein the electrolytic reduction is performed using a proton donating solution as the anolyte. 6. A solution containing a basic compound after separating 1-aminoanthraquinones obtained by the method according to any one of claims 1 to 5 is recycled for electrolytic reduction. The method according to any one of (1) to (5). 7. The method according to claim 6, wherein the solution containing the basic compound after separating the 1-aminoanthraquinones is reused for electrolytic reduction after removing the organic compound contained in the solution. . 8. The method according to claim 7, wherein the solution containing the basic compound after separating the 1-aminoanthraquinones is brought into contact with an adsorbent to remove the organic compound contained in the solution. 9. The method according to claim 1, wherein the electrolytic reduction is carried out in the presence of an antifoaming agent.