JPH0144690B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves reacting phthalic anhydride and p-chlorophenol in fuming sulfuric acid in the presence of a boron catalyst to obtain a boron complex of 1,4-dihydroxyanthraquinone. is directly chlorinated with a chlorinating agent in the same reaction medium to obtain the boron complex of 5,8-dichloro-1,4-dihydroxyanthraquinone, and the chlorinated product is diluted with the acid medium at 70-110°C. The present invention relates to a method for producing 5,8-dichloroquinizarin, thereby obtaining 5,8-dichloroquinizarin.

The novel process of the present invention follows the following reaction scheme.

X=OH, halogen atom, O-acyl group Y=C-C alkyl group, halogen atom, preferably hydrogen 5,8-dichloroquinizaline is obtained by diluting the chlorinated product with the acid medium.
Also, without isolating this dichloro complex, 140
Hydrolysis with 80% concentrated sulfuric acid to 25% fuming sulfuric acid at ~220°C It is known from the prior art to prepare quinizarin from phthalic anhydride and p-chlorophenol. It is also known from the prior art to obtain 5,8-dichloro-1,4-dihydroxyanthraquinone by chlorination of quinizarin and to hydrolyse 5,8-dichloro-1,4-dihydroxyanthraquinone to diquinizarin.

Until now, these three steps were performed separately. It is very important to control the acid concentration and temperature conditions of the reaction medium at each stage in order to obtain the pure product in good yield at each stage, so by combining these three steps, This is because it could not be foreseen that they could be carried out continuously in a unified process without isolation of intermediates under more favorable environmental and economic conditions.

In sulfuric acid or oleum, boric acid or according to German Patent Publication No. 2014566 boric acid and boron 3
In the method for obtaining quinizarine by the reaction of phthalic anhydride and p-chlorophenol at a temperature of 170 to 210°C in the presence of a halide and/or boron trihalide complex compound, quinizarine is obtained from the reaction melt. After dilution with water and, if desired, work-up with alkali in the presence of an oxidizing agent, the precipitated reaction product is isolated by separation.

The lower the temperature at which it is formed and the higher the concentration of sulfuric acid, the higher the purity of the 1,4-dihydroxyanthraquinone (quinizarine) obtained by the method described above. However, at 180°C, the reaction proceeds so slowly that it jeopardizes economic production;
Although it proceeds at an acceptable rate at 0.degree. C., the purity of the product is less than desired. Performing the reaction with higher concentrations of sulfuric acid increases the purity of the reaction product but decreases the yield. The lower the sulfuric acid concentration, the greater the amount of acid that must be used. In both cases large amounts of waste sulfuric acid accumulate and its treatment by neutralization and removal of the resulting large amounts of salts poses environmental and economic problems.

Furthermore, the chlorination of quinizarin as an intermediate is also carried out in concentrated sulfuric acid or in fuming sulfuric acid. Dilution of the reaction mixture during subsequent processing again results in large amounts of waste sulfuric acid. The hydrolysis also requires large amounts of sulfuric acid.

On the one hand, special requirements from the point of view of reaction kinetics,
On the other hand, the high purity required for quinizarin requires that each reaction be carried out under optimal reaction conditions, which gives rise to the disadvantages mentioned above, in particular environmental disadvantages. There was therefore a sincere need for an integrated process in which the three reaction steps described above could be carried out sequentially in the same reaction medium, avoiding changes in the acid concentration.

Surprisingly, 1,4-dihydroxyanthraquinone can be obtained at higher temperatures and using substantially less concentrated sulfuric acid in yields at least as good as or better than in the known process. It has been found that the subsequent chlorination can be carried out in a medium of concentrated sulfuric acid or fuming sulfuric acid without isolation of the quinizarin obtained as intermediate and that diquinizarin can be obtained by subsequent hydrolysis of the chlorinated product. Served.

A new method for the preparation of 5,8-dichloro- or 5,8-dihydroxyquinizaline by the reaction of phthalic anhydride with p-chlorophenol, the reaction is carried out in fuming sulfuric acid, B ₂ O ₃ , H ₃ BO ₃ or The process is carried out continuously or discontinuously at 180 to 220°C in the presence of boron halide, and the boron complex of 1,4-dihydroxyanthraquinone obtained as an intermediate is treated with a chlorinating agent without directly isolating it. In the same reaction medium used, 20
Chlorination at ~150℃ and the chlorination product at ~70~110
The 5,8-dichloroquinizaline obtained by hydrolysis is isolated by diluting the acid medium at °C. or acid medium without isolation 140-220
The 5,8-dihydroxyquinizaline obtained by hydrolysis can be isolated by dilution from 80% concentrated sulfuric acid to 25% fuming sulfuric acid at °C.

The new method for producing 1,4,5,8-tetrahydroxyanthraquinone further includes combining p-chlorophenol and phthalic anhydride in fuming sulfuric acid with B ₂ O ₃ ,
In the presence of _H3BO3 or _boron halide, 180~
The reaction is carried out continuously or discontinuously at 220°C, preferably between 200 and 210°C, and the boron complex of 1,4-dihydroxyanthraquinone obtained as an intermediate is treated with common chlorinating agents without direct isolation. chlorinate at 20-150 °C in the same reaction medium, optionally using a chlorination catalyst, and the chlorinated product at 140-220 °C in 80% concentrated sulfuric acid to 25 °C. % fuming sulfuric acid, if desired with further addition of boric acid, and isolation thereof. Isolation of the reaction product is usually carried out by reducing the concentration of fuming sulfuric acid.

The new process for the preparation of 5,8-dichloro-1,4-dihydroxyanthraquinone by the reaction of phthalic anhydride and p-chlorophenol also comprises the reaction in fuming sulfuric acid, B ₂ O ₃ , H ₃ BO ₃ or The process is carried out continuously or discontinuously at 180 to 220°C in the presence of a boron halide, and the boron complex of 1,4-dihydroxyanthraquinone obtained as an intermediate is directly treated with ordinary chlorine without isolation. chlorination agent in the same reaction medium at a temperature range of 20-150°C, and the chlorinated product at 70-110°C.
and isolating the hydrolyzed product.

Both starting materials can be reacted in stoichiometric amounts. However, stoichiometric amounts of the cheaper phthalic anhydride
It is advantageous to use an excess of up to 1.5 times, especially 1.3 times.

The above reaction is based on 35% oleum, with a weight ratio of oleum to phthalic acid of 1:1 to 4:1, advantageously
1.1-1.5:1, boron oxide to phthalic anhydride weight ratio 1:2-1:4. The concentration of fuming sulfuric acid is not critical and can be, for example, 70%.

It is advantageous to further add 50 to 70% oleum and/or chlorosulfonic acid to the reaction mixture before chlorination.

Examples of suitable chlorinating agents are chlorine, chlorosulfonic acid, thionyl chloride or sulfuryl chloride.
When using chlorine, slightly elevated pressure of up to 3 bar may be applied. It is advantageous to carry out the chlorination in the presence of a halogenation catalyst. Chlorosulfonic acid can also be used as a solvent in the presence of fuming sulfuric acid.

The new process is carried out, for example, by adding boron oxide to 35% oleum with stirring at 100-150 DEG C., preferably at 120-130 DEG C. Phthalic anhydride and then p-chlorophenol are then added at 130-150°C and the reaction mixture is heated at 180-220°C, preferably 200-210°C, with thorough stirring.
and hold at this temperature for 6 to 15 hours. Once the reaction is complete, the reaction mixture is cooled to 160-170°C, maintaining the consistency of the reaction medium at the desired limits during the subsequent cooling to about 50-120°C, while maintaining favorable conditions for the subsequent chlorination. to produce at least 2 of the amount of oleum added at the start of the above reaction.
Add double volume of 50-75% oleum and/or chlorosulfonic acid. Halogenation catalyst e.g.
SCl ₂ , but preferably iodine, is added and then chlorination is carried out using one of the chlorinating agents mentioned above at a temperature of 20-150°C, preferably 50-100°C, until all the quinizarin is chlorinated. 5,8-dichloroquinizaline is isolated by eliminating excess chlorine and diluting the acid medium of the reaction mixture. or reaction mixture with water, preferably sulfuric acid concentration 85-95%
Dilute to . Then reduce the reaction mixture to 140
Diquinizarin is precipitated and isolated by heating again at ˜220° C. for about 3 to 15 hours, followed by further dilution with water. It is advantageous to add small amounts of nonionic surfactants to the reaction mixture. The addition of surfactants allows for better crystal formation, thereby improving the filtration properties of the product and the flow properties of the dry product.

If a reactive substrate containing a stable substituent is used, the resulting product is the corresponding substituted diquinizarin. An example of such a reactive substrate is C ₁ −
C ₄ alkylated or halogenated phthalic anhydride and/or p-chlorophenol.

The new method of the invention is much more efficient than the previously applied methods, which use individual steps. For example, a good quality product with a yield of more than 90% (p-
(based on chlorophenol), whereas the sum of the yields of the individual single-step methods is at most only 80
%. Furthermore, the following operations normally applied in single-step methods are no longer necessary.

pouring the reaction mixture of the boron complex of quinizarine on ice or in water; hydrolyzing the boron complex of quinizarine to quinizarine; preparing a solution of the boron complex of quinizarine for the second reaction step; and chlorinating the solution. preparing a boron complex of quinizarine in sulfuric acid; filtering quinizarine and dichloroquinizarine;
washing and drying, the first two containing boric acid and sulfuric acid respectively;
Treating wastewater in two stages.

The omission of the aforementioned operations results in significant environmental and economic advantages, the most important of which is that the wastewater contains approximately 50% less boron compounds and, due to the changes in the applied method, more than 70% less sulfuric acid. time, personnel, equipment and energy are saved.

The dichloroquinizalines obtained by the process of the invention can be reacted to dyes without further purification, for example by condensation with amines.

The following examples illustrate the invention without limiting it. Parts are by weight unless otherwise specified.

Example 1 (Reference example) Add 77% of sulfuric acid monohydrate to a 500ml sulfonated flask.
and 89 parts of 66% oleum.
The temperature rises to 45-50 ° C. Then boron oxide 38
Add the mixture while stirring until the temperature reaches 120-125℃.
rise to The time required for this addition is approximately 20 minutes. A milky solution is obtained. The contents of the flask are heated to 150°C and then at 130-150°C first 100 parts of phthalic anhydride and then 64 parts of p-chlorophenol are added. Then the reaction mixture
Heat to 205±2°C and hold at this temperature for 14 hours.

The reaction mixture is then cooled to 160-170°C and then, during cooling to 100°C, 40 parts of 66% oleum are slowly added dropwise to ensure good stirring. Then another 66% oleum 325
Add dropwise at 70°C while cooling. After adding 5 parts of finely ground iodine, chlorine is introduced until chromatographic analysis of the sample no longer shows the presence of quinizarin.

Excess chlorine is removed from the reaction mixture with air or nitrogen. The concentration of sulfuric acid is then brought to 90% by dilution with water, and the reaction mixture is stirred at 180° C. until diquinizarin is no longer detected by chromatographic analysis. The solution is about 6%
Poured into 200 parts of aqueous sodium bisulfite solution,
Then add 200 parts of a commercially available polyether type surfactant. Stir the batch at 85-90°C for 1-3 hours and filter. The filter cake is washed hot until it becomes neutral, and when dried, 1,4,5,8-
125 parts of tetrahydroxyanthraquinone (91.8% of theory based on chlorophenol) are obtained.

The reaction mixture prepared by the method of this example is precipitated as described above without the addition of surfactant.
The filtration properties of the product are very poor.

Example 1(a) Variant for obtaining 5,8-dichloroquinizaline The chlorination was carried out as described in Example 1, the excess chlorine was then driven off from the reaction mixture using nitrogen, and the reaction mixture was reduced to approx. Pour into 2000 parts of 6% aqueous sodium bisulfite solution. Add 20 parts of a commercially available polyether type surfactant and heat the mixture to 85-90°C.
Stir for 2 hours and filter. When the filter cake is washed with heat until it becomes neutral and dried, 5,8
-145.3 parts of dichloroquinizarin (94% of theory based on chlorophenol) are obtained. Chlorine content:
22.9% (theoretical amount: 22.94%).

Comparative Example The reaction mixture prepared according to the method of Example 1 is poured into an aqueous bisulfite solution and stirred at 85-90° C. for the same time as in Example 1, but without surfactant. The product had significantly worse filtration properties than in Example 1, a somewhat lower yield, and a lower chlorine content.
It is 24.5%.

Example 2 38 parts of boron oxide are added to 166 parts of 66% oleum and carefully heated to 150°C (exothermic reaction). Then 100 parts of phthalic anhydride and 64.3 parts of chlorophenol are added and the mixture is heated to 205°C and stirred for 14 hours. The mixture is cooled to 160°C and kept stirrable by dropwise addition of 40 parts of 66% oleum during the subsequent cooling to 90°C. Then, gradually add 400 parts of 66% oleum, 5 parts of iodine, and finally 550 parts of chlorosulfonic acid. The reaction mixture is
until no more quinizarin is present in the sample.
Stir at 90-100℃. The reaction mixture is then poured slowly into 3000 parts of ice water to which 150 parts of 40% bisulfite solution and 20 parts of surfactant have been added. The batch is refluxed for 3 hours and filtered.
Washing and drying the filter cake gives 5,8-dichloroquinizaline in the same good yield as in Example 1(a).

Example 3 To 435 parts of 9% oleum are then added 0.02 parts of nitrobenzenesulfonic acid, 42.9 parts of H _{3 BO 3} and 97.9 parts of phthalic anhydride, and when the solution becomes clear, 64.3 parts of chlorophenol are added. The temperature of the mixture is raised to 195°C in 5 hours, kept at this temperature for 10 hours, and then cooled to 65°C. 5 parts of iodine and 66
After adding 800 parts of fuming sulfuric acid, chlorine is introduced at 65-70°C. After the chlorination is complete, the batch is worked up as described in Example 1. Yield: 126 parts of 5,8-dichloroquinizarin.

Example 4 To 200 parts of 20% oleum, first add 38 parts of boron oxide, then at 120°C add 100 parts of phthalic anhydride and 64.3 parts of chlorophenol. The mixture was heated to 200℃ for 16
Heat for an hour and then cool to 65°C. Add 400 parts of 66% oleum and 5 parts of iodine, then introduce chlorine. Once the chlorination is complete, the batch is worked up as described in Example 1. Yield: 128 parts of 5,8-dichloroquinizarin.

Examples 5 and 6 The procedure of Example 2 is repeated using the required amounts of thionyl chloride and sulfuryl chloride, respectively, as chlorinating agents instead of chlorosulfonic acid. In each case equally good target products are obtained in the same good yields as in Example 1(a).

Example 7 (Reference example) Adjusting the sulfuric acid concentration to 95% after chlorination,
The reaction mixture was stirred until no starting material was detected.
Repeat the method of Example 1, except stirring at 200°C. 1,4,5,8-tetrahydroxyanthraquinone is obtained in the same good yield as in Example 1.

Example 8 (Reference Example) The method of Example 7 was repeated to carry out the hydrolysis of 5,8-dichloroquinizaline by addition of 25 parts of boric acid, and in half the reaction time, 1,4,
5,8-tetrahydroanthraquinone is obtained.

Claims (1)

[Claims] 1. Phthalic anhydride and p-chlorophenol are continuously or discontinuously treated in fuming sulfuric acid at 180 to 220°C in the presence of B ₂ O ₃ , H ₃ BO ₃ or boron halide. The boron complex of 1,4-dihydroxyanthraquinone obtained as an intermediate is directly chlorinated with a chlorinating agent at 20-150°C in the same reaction medium without isolation, and the chlorinated product is 70〜
A process for the preparation of 5,8-dichloroquinizarine, which consists of hydrolysis to 5,8-dichloroquinizarine by diluting the acid medium at 110°C. 2. Adding to the reaction medium before chlorination 50-70% oleum and/or chlorosulfonic acid in an amount at least twice the amount of oleum used at the beginning of the reaction. Method described. 3. Claim 1 in which the first reaction (condensation reaction) is carried out at 200-210°C and the chlorination is carried out at 50-100°C.
The method described in section. 4. The method according to claim 1, wherein p-chlorophenol and phthalic anhydride are used in a stoichiometric ratio of 1:1 to 1:1.5. 5. Claim 1 in which fuming sulfuric acid and furalic anhydride are used in a weight ratio of 1:1 to 4:1 in the first step.
The method described in Section 1 or Section 2. 6 Boron oxide and phthalic anhydride in a weight ratio of 1:2
The method according to claim 1 for use at a ratio of ~1:4. 7. The method according to claim 1, wherein the chlorination is carried out in the presence of a halogenation catalyst. 8. The method according to claim 1, wherein chlorine is used as the chlorinating agent. 9. The method according to claim 1, wherein a nonionic surfactant is used as the acid medium after dilution.