DE2228334C3 - Process for the production of a-phenyl ethers of anthraquinones - Google Patents

Description

The invention relates to a process for the preparation of Λ-phenyl ethers of anthraquinone from Λ-nitroanthraquinones.

a-Aryl ethers of anthraquinone are after German Patent 1 58 531 by reacting the corresponding mono- or dinitroanthraquinones obtained with aromatic hydroxy compounds in the presence of potassium or sodium hydroxide. However, this process has the disadvantage that a large excess of the hydroxy compound is involved at the same time serves as a solvent, and is required on the alkali hydroxides, which is why the mother liquors must be worked up after isolation of the reaction product. Because of the content of Alkali hydroxide, phenolate and nitrite, this work-up is very costly and with great losses aromatic hydroxy compound connected.

The object of the present invention was to find an easy-to-use method that at the same time does not have the disadvantages of the prior art method outlined.

It has now been found that you can α-Phenyläther des Anthraquinones in a technically and economically advantageous manner by converting -nitroanthraquinones with phenols in the presence of potassium or sodium hydroxide at elevated temperature, if the implementation of the «-nitroanthraquinone at temperatures between 80 and 180 ° C and in the presence from 0.5 to 2 moles of an acid-binding agent in water-miscible aprotic solvents carried out using 1.0 to 1.9 mol of a phenol per mole of nitro group.

According to the process of the invention, pure a-phenyl ether des is obtained in a high space-time yield Anthraquinones.

Aprotic solvents are understood to mean those solvents that are not capable of to release protons under normal conditions. As are water-miscible aprotic solvents for example the N.N-dialkyl-substituted carboxamides like Ν, Ν-dimethylformamide, N, N-diethylformamide, Ν, Ν-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylpropionamide, Ν, Ν, Ν ', Ν'-tetramethylurea and N-methylpyrrolidone, aliphatic sulfoxides or sulfones such as dimethyl sulfoxide, tetramethylene sulfone, Hexamethylene sulfone or dialkyl ethers of glycols and polyglycols such as ethylene glycol dimethyl ether, Trimethylene glycol dimethyl ether or diethyl ether, ethylene glycol diethyl ether and diethyl glycol dimethyl or diethyl ether and mixtures of these solvents.

For economic reasons, the Ν, Ν-dialkylcarboxamides are particularly suitable. Of these Ν, Ν-dimethylformamide and N-methylpyrrolidone are particularly preferred.

Acid-binding agents are, for example, the alkali carbonates, alkali metal hydroxides and the alkali metal salts of weak carboxylic acids. In detail, for example, sodium hydroxide, Potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, Potassium acetate, sodium benzoate, potassium benzoate, sodium propionate, potassium propionate or their mixtures in Consideration.

For the method according to the invention, potassium hydroxide and potassium carbonate are preferably used as Acid-binding agents are used, as they provide the highest space-time yields and the purest reaction products receives.

In addition to the unsubstituted phenol, the phenol also includes those in the nucleus by alkyl or halogen substituted phenols such as o-cresol, p-cresol, m-cresol, p-tert-butylphenol, o-chlorophenol, m-chlorophenol, p-chlorophenol; o-bromophenol, m-bromophenol, p-bromophenol, 2,4-dichlorophenol, 4-chloro-o cresol, 3,5-dimethylphenol into consideration.

For economic reasons, the unsubstituted phenol is of particular technical importance.

The reaction is expediently carried out by adding the acid-binding agent to the suspension or solution of the a-nitroanthraquinone in the water-miscible aprotic solvent and the phenol and heating the mixture to the desired reaction temperature with stirring. The reaction is conveniently carried out at temperatures between 80 and 180 ⁰ C, preferably between 110 and 15O ⁰ C. The duration of the reaction depends on the temperature and generally lies between 1 and 5 hours. If the reaction is carried out, for example, in the temperature range between 120 and 150 ° C., the reaction is complete after 2 to 3 hours.

The reaction can be followed by chromatography on the decrease in the α-nitroanthraquinone compound and so the end of the implementation can be determined.

The reaction products are obtained from the reaction mixture in a conventional manner by dilution precipitated with water or with water-miscible alcohols and the precipitation by filtering, centrifuging or decantation separated from the alkaline mother liquor. The filter material is then washed with water washed neutral and dried.

A particularly advantageous and therefore preferred one

<> 5 variant of the work-up of the reaction mixture is, however, that the reaction mixture is diluted with isopropanol, which is in the reaction mixture contained I reaction product together with

the salts present in the mixture are precipitated and then separated from the mother liquor. This is a largely salt-free mother liquor obtained, which again without difficulty by fractional distillation can be worked up. The separation of the nitrite-containing salts from the reaction products is done by washing out with warm water.

The advantage of the method of the present invention over the method of the prior art The technique is that when using water-miscible aprotic solvents Amount of acid-binding agents and the amount of phenol can be greatly reduced and that the Implementation takes place in a high space-time yield.

According to the process, pure aryl ethers of anthraquinone are obtained. These are valuable intermediates for the synthesis of dyes.

The following examples are intended to further illustrate the process of the invention. The ones mentioned below Parts and percentages relate to weight.

example 1 1-phenoxyanthraquinone

50 parts of 1-nitroanthraquinone (90%), 100 parts of dimethylformamide, 40 parts of phenol and 30 parts of potassium carbonate are stirred ^{at 140 ° C. for 2.5 hours.} After cooling to 100 ° C., the reaction mixture is diluted with 250 parts of isopropanol. After cooling to room temperature, the precipitate is filtered off with suction and washed with warm water until neutral and dried at 100 ⁰ C. Yield: 40 parts of a yellow product which melts at 126.degree.

Example 2 1,5-diphenoxyanthraquinone

33 parts of 1,5-dinitroanthraquinone, 40 parts of dimethylformamide, 30 parts of phenol and 30 parts of potassium carbonate are stirred ^{at 140 to 150 ° C. for 2 hours.} After cooling to 100 ^° C., the reaction mixture is diluted with 200 parts of isopropanol and cooled. The precipitate is filtered off with suction, washed with warm water and dried at 100 ⁰ C. Yield: 36 parts of a yellow product with a melting point of 222 ° C.

Example 3 Mixture of 1,5- and 1,8-diphenoxyanthraquinone

50 parts of a mixture, as is obtained in the dinitration of anthraquinone and which contains 49.4% 1,5-dinitroanthraquinone and 36.6% 1,8-dinitroanthraquinone, are in 80 parts of N-methylpyrrolidone, 30 parts of phenol and 20 parts of potassium hydroxide at 110 to 130.degree Stirred for 2 hours. After cooling, the reaction mixture is diluted with 300 parts of methanol and stirred for 1 hour. The precipitate is filtered off with suction, washed with warm water and dried. Yield: 50 parts of a yellow product.

Example 4 Mixture of 1,5- and 1,8-diphenoxyanthraquinone

6 parts of a mixture of 1,5- and 1,8-dinitrianthraquinone (see Example 3), 4.8 parts of phenol, 4.8 parts anhydrous potassium carbonate and 6 parts dimethylfor mamid are stirred for 1.5 hours at 140 to 150 ⁰ C, with about 0.9 parts water distilled off. It is then cooled to 100 ⁰ C., are 14 parts of isopropanol and cooled to 20 ° C. The precipitate is filtered off with suction, washed neutral first with 25 parts of isopropanol and then with warm water.

After drying, 62 parts of a yellow powder are obtained. The mother liquors containing isopropanol can can be worked up without difficulty by fractional distillation.

Example 5

Mixture of 1,5- and 1,8-di- (o-chloro) -phenoxyanthraquinone

50 parts of a mixture of 1,5- and 1,8-dinitroanthraquinone (see Example 3), 50 parts of o-chlorophenol, 50 parts of potassium carbonate and 100 parts of N-methylpyrrolidone are stirred ^{at 110 to 120 ° C. for 2 hours} the reaction product is precipitated by adding 200 parts of methanol, filtered off with suction and dried. Yield: 66 parts of a yellow powder.

Analysis for: C ₂₆ Hi ₄ I (460):

Calculated: -C 67.7; H 3.4; O 133; Cl 15.2; Found .: C 67.8; H 3.2; O 13.6; Cl 15.8.

Example 6

Mixture of 1,5- and 1,8-di (p-terL-butyl) -phenoxyanthraquinone

The reaction is carried out as described in Example 5, the o-chlorophenol being replaced by 50 parts p-tert-butylphenol is replaced. Yield: 26 parts of a yellow powder.

Analysis for: C ₃₄ H ₃₂ O ₄ (S (M):

Calculated: C 81.0; H 6.36; O 12.7; found: C, 80.5; H 6.50; O 13.0.

Example 7 1,5-diphenoxy-2-methylanthraquinone

50 parts of 1.S-Dinitro ^ -methylanthraquinone, 100 parts Dimethylformamide, 60 parts of potassium carbonate and 40 parts of phenol are heated at 140 to 150 ° C. for 3 hours touched. After cooling, the reaction mixture is diluted with 300 parts of isopropanol and the Sucked off precipitation, washed with isopropanol and then with warm water and dried. 90 parts of an ocher-colored powder with a melting point of 166 ° C. are obtained.

Example 8

50 parts of a mixture of 1,5- and 1,8-dinitroanthraquinone (see Example 3), 35 parts of phenol, 20 parts powdered potassium hydroxide and 300 parts of N-methylpyrrolidone are 2 to 3 hours at 120 ° C touched. After cooling, it is diluted with 500 parts of water or methanol, and the precipitate is filtered off with suction and washed neutral with water. 49.5 or 53.1 parts of a yellow product are obtained.

Example 9

50 parts of a mixture of 1,8- and 1,5-dinitroane ! hrachinon (see example! 3), 35 parts of phenol,! 5 parts

pulverized sodium hydroxide and 150 parts of N-methylpyrrolidone are ^{stirred for 2 to 3 hours at 120 to 130 °} C. After cooling, the reaction mixture is poured onto a mixture of methenol and water (1: 1 parts by weight), the precipitate S is suctioned off and washed neutral with water .
Yield: 203 parts of a yellow product.

Example ok

50 parts of a mixture of 1,5- and 1,8-Dinilroanthrachinon (Example 3), 35 parts of phenol, 40 parts of sodium acetate anhydrous, and 150Teilen N, N-dimethylformamide are stirred for 3 hours at 120 to 130 ⁰ C. After cooling, water is poured onto 1000 parts and the precipitate is filtered off and washed neutral.
Yield: 26.2 parts of a yellow product.

Example 11

50 parts of a 1,5 / 1,8-dinitroanthraquinone mixture (Example 3), 35 parts of phenol, 30 parts of potassium hydrogen carbonate and 100 parts of N, N-dimethylformamide are stirred ^{at 140 to 150 ° C. for 3 hours.} At 100 ⁰ C the reaction mixture are added 300 parts of isopropanol and filtered off with suction after cooling the precipitation and washed with water until neutral.
Yield: 36 parts of a yellow product.

Example 12

The procedure described in Example 5 is followed, except that the same amount of p-chlorophenol is used instead of o-chlorophenol. 65 parts of a yellow product with a melting point of 182 to 187 ^° C. are obtained.
Analysis:

Found: C, 67.5; H 3.3, Cl 15.7, O 13.6%

Example 13

If the procedure is as indicated in Example 5, but instead of the o-chlorophenol, 50 parts of p-cresol are used 30 parts of a yellow product are obtained with a melting point of 205 ° to 215 ° C.

Analysis:

Calculated: C 80.0, H 4.75, O 15.3%

found: C 80.5, H 5.1, O 15.0%.

If, instead of the p-cresol, the same amount of o- or m-cresol is used, this is obtained corresponding products.

Example 14

20 parts!, S / l ^ -Dinitroanthraquinone mixture (see Example 3), 50 parts of N-methylpyrrolidone, 20 parts of anhydrous potassium carbonate and 30 parts of 2,4-dichlorophenol are ^{stirred for 3 hours at 120 to 130 0} C and then the reaction mixture diluted with 200 parts of isopropanol. After work-up, 16.1 parts of a yellow product are obtained, which is a; Fixed point of 262 to 265 ° C.

Example 15

50 parts of 1S / 1-dinitroanthraquinone mixture (see Example 3), 35 parts of phenol, 30 parts of anhydrous potassium carbonate and 100 parts of dimethyl sulfoxide are stirred ^{at 140 to 150 ° C. for 3 hours.} After cooling to 90 ^° C., 300 parts of isopropanol are added to the reaction mixture and the mixture is cooled, the precipitate is filtered off with suction and washed neutral with water.
Yield: 49 parts of a yellow-brown product.

Example 16

The procedure is as in Example 15, except that 100 parts of sulfolane are used instead of the dimethyl sulfoxide. Man receives 50 parts of a yellow product after work-up.

Example 17

Proceeding as indicated in Example 15, but using 100 instead of dimethyl sulfoxide Parts of Ν, Ν-dimethylacetamide, 48 parts of a yellow product are obtained.

Example 18

50 parts of 1,5- / 1,8-dinitroanthraquinone mixture (Example 3), 35 parts of phenol, 30 parts of anhydrous potassium carbonate and 100 parts of triethylene glycol dimethyl ether are stirred ^{at 140 to 150 ° C. for 3.5 hours.} After cooling to 90 ° C., 300 parts of isopropanol are added and, after cooling to room temperature, the precipitate is separated off and washed neutral with water.
Yield: 48 parts of a yellow-brown product.

Example 19

50 parts of a 1,5- / 1,8-dinitroanthraquinone mixture (see Example 3), 30 parts of phenol, 35 parts of anhydrous potassium carbonate and 100 parts of N, N-dimethylformamide are ^{stirred at 100 °} C. for 6 to 7 hours, with water being slowly added distilled off. After cooling, 300 parts of isopropanol are added, the precipitate is filtered off with suction and washed neutral with water. 42 parts of a yellow product are obtained, which may still contain small amounts of starting maierial.

Example 20

One proceeds as specified in Example 19 but using, instead of N, N-Dimethy! Formamide the same amount of N-methylpyrrolidone as a solvent, and the reaction at 170 to 180 ⁰ C. The reaction has already ended after one hour. After working up, 45 parts of a yellow-brown product are obtained which no longer contain any starting material.

Claims (4)

Patent claims: 1. A process for the preparation of -phenyl ethers of anthraquinone by reacting a-nitroanthraquinones with phenols in the presence of potassium or sodium hydroxide at elevated temperature, characterized in that the reaction of the a-nitroanthraquinone at temperatures between 80 and 180 ⁰ C and carried out in the presence of 0.5 to 2 moles of an acid-binding agent in water-miscible aprotic solvents, 1.0 to 1.9 moles of a phenol being used per mole of nitro group. 2. The method according to claim 1, characterized in that the acid-binding agent used is alkali metal carbonates, Alkali salts of weak carboxylic acids or mixtures thereof are used. 3. Process according to claims 1 or 2, characterized in that potassium carbonate is used used as an acid-binding agent. 4. Process according to Claims 1 to 4, characterized in that the aprotic solvent is used N-methylpyrrolidone or Ν, Ν-dimethylformamide begins.