JPS622580B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for mononitrating anthraquinone using a nitric acid/sulfuric acid mixture, which allows obtaining 1-nitroanthraquinone in high yield. A number of methods are known for the mononitration of anthraquinones, in which the nitration of anthraquinones is carried out with nitric acid alone or with nitric acid and other substances (e.g. U.S. Pat.
No. 2874168, German Patent Application Publication No.
2103360, 2232464 and 2241627 and Polish Patent Specification No. 46428). These methods are disadvantageous because they require long reaction times and/or the use of relatively large amounts of inorganic acids. Also, in some cases these methods use highly erosive reagents and therefore particularly erosive resistant materials must be used in constructing the necessary equipment. Methods for the mononitration of anthraquinones with sulfuric/nitric acid mixtures have already been known for some time; see, for example, Liebermann, Berichte 16, page 54 (1883). In this process, 1-nitroanthraquinone is obtained in yields of only about 60% if the nitration is carried out such that less than 5% of unreacted anthraquinone remains in the reaction product. This low yield is due to the inability to adequately protect the resulting anthraquinone from further nitration to dinitroanthraquinone. Various examples of this situation include, for example, German patent application publication specification no.
Described in No. 2039822. A method for producing 1-nitroanthraquinone by nitrating anthraquinone in sulfuric acid is also described in German Patent Application No. 2039822. 75% by weight of 1-
The process is carried out in 75-82% sulfuric acid at temperatures ranging from about 20 to about 60°C until nitroanthraquinone is produced.
According to Example 1 of the above published specification, 78% sulfuric acid
51 parts of 98% nitric acid are used per 160 parts, ie, there is substantially less nitric acid than sulfuric acid. Disadvantages of this method are the long reaction times required (12-15 hours according to Example 1) and the sensitivity of the reaction process to temperature changes and to the concentration of the nitrated acid, which is explained in the German patent application It is described in Publication Specification No. 2204516. Furthermore, German patent application publication specification no.
A significant drawback of the process in No. 2039822 is that it requires a large amount of sulfuric acid for the anthraquinone, which either requires expensive work-up after the end of the reaction or leads to severe contamination of the eluent. provoke. These drawbacks have already been pointed out in DE-A-2233185. The methods according to German Patent Application No. 2204516 and German Patent Application No. 2233185 do not completely eliminate the disadvantages of the method according to German Patent Application No. 2039822, and the reason for this is that According to German Patent Application No. 2204516, the reaction is likewise carried out with a relatively large amount of acid relative to the anthraquinone, and according to DE 22 33 185 the amount of acid used is This is because, in addition, the reaction must be carried out in the presence of an inert organic solvent, although this is substantially less so. Now, according to the present invention, anthraquinone is prepared in a nitric acid/sulfuric acid mixture at a weight ratio of nitric acid to sulfuric acid of about 1:1 to about 2:1, and a weight ratio of sulfuric acid to anthraquinone of about 0.5:1 to about 1. :1, and the weight ratio of sulfuric acid to water is approximately 2.5:1.
~5.5:1, where the weight ratio is based on the sum of the points used, in the temperature range of 45 to 70°C until the anthraquinone content is less than 3% by weight with respect to the total amount of anthraquinone compounds. A method has now been found for the mononitration of anthraquinones with a nitric acid/sulfuric acid mixture consisting of: The process according to the invention can be carried out at temperatures between 45 and 70°C, preferably between 48 and 60°C. Furthermore, it is advantageous to carry out the initial stages of the nitration at a relatively low temperature within the indicated range and to increase the reaction temperature to a relatively high temperature within the indicated range as the mononitroanthraquinone formation progresses. . The initial stage of nitration is carried out at 45-55℃, preferably
It is carried out at a low temperature in the range of 48-53℃, and after mononitration of more than 50% of the anthraquinone used, 55-70℃
It is particularly preferred to increase the temperature by .degree. C., preferably about 60.degree. If the anthraquinone content in the nitration mixture has reached a value of about 3% by weight with respect to the sum of all anthraquinone compounds, within 1 hour,
It is advantageous to keep the maximum reaction temperature at 60°C, otherwise mononitroanthraquinone,
Among them, whenever 1-nitroanthraquinone is further observed, there is a possibility that it will react to form dinitroanthraquinone. The method according to the invention can be carried out in various ways. For example, it is possible to first introduce all the nitric acid/sulfuric acid mixture and to this the anthraquinone. The anthraquinone can be introduced all at once or over a period of up to 3 hours. The process also allows the nitric acid/sulfuric acid mixture and the anthraquinone to be metered separately but simultaneously into the mixture in which the reaction has been fully or partially completed. Furthermore, the process can be carried out in a multistage reaction process, for example a Kama cascade process, and the nitric acid/sulfuric acid mixture and the anthraquinone are metered simultaneously into the first element of the reaction cascade in a continuous process. The process according to the invention can also be carried out in a reaction tube, and the nitric acid/sulfuric acid mixture and the anthraquinone can be metered into the reaction tube simultaneously in a continuous manner. This method or e.g. moisture content 22% by weight
All or part of the anthraquinone is stirred in a portion of the above nitric acid/sulfuric acid mixture and the remaining nitric acid/sulfuric acid mixture with a water content of e.g.
It is also possible to meter in after 3 hours. In the latter case, nitration occurs gradually in mixed acids containing relatively high proportions of water (e.g. water content >22% by weight) and in anhydrous or small amounts of water (e.g. <5% by weight).
Nitration begins at an appreciable rate only when a nitric acid/sulfuric acid mixture containing is added. This process is advantageous if, for example for heat removal reasons, the anthraquinone has to be added gradually in the initial stage, ie the HNO ₃ /anthraquinone ratio is >2. Thus, the pernitration that would result if mixed acids were used is avoided, and the water content corresponds to the amount of the total mixed acid (equal to the average value of all mixed acids added). In the process of the invention, it is important that a liquid phase consisting mainly of organic components is formed during the nitration reaction. This phase will be described below as a "liquid organic phase." It occurs at the above weight ratios and temperatures and induces the formation of an emulsion of a low specific gravity liquid organic phase consisting primarily of anthraquinone and mixed acid and an inorganic phase that is liquid and contains a residual nitric and sulfuric acid moiety. Generally the liquid organic phase consists of greater than 50% of anthraquinone and contains nitric acid and sulfuric acid in a weight ratio of greater than 3:1, preferably greater than 4:1. The liquid organic phase contains the remainder nitric acid and sulfuric acid (the weight proportion of sulfuric acid exceeds the weight proportion of nitric acid) and a small amount of dissolved organic substances. The production of a liquid organic phase is of critical importance in carrying out the method according to the invention. On the one hand, it ensures that the further nitration of the 1-nitroanthraquinone formed and present in the liquid organic phase is delayed, and on the other hand, this results in a very concentrated mixture, i.e. relative to the anthraquinone used. It is possible to carry out the nitration in a relatively small amount of acid. Thus, for example, nitration mixtures can be handled industrially without problems due to anthraquinone contents of more than 50% by weight; this means that they are in a stirrable state and can be pumped without particular difficulties. . The formation of this liquid organic phase has not previously been observed during the nitration of anthraquinones with nitric acid or nitric acid/sulfuric acid mixtures. Known methods for the nitration of anthraquinones in a heterogeneous phase, for example German Patent Application No.
In No. 2039822, no liquid organic phase of this type was produced, but a solid phase containing virtually only anthraquinone was produced. Even if the temperature increases during or after the addition of nitric acid in Example 1, no liquid organic phase forms. Similar to the process according to the invention, attempts have been made to carry out the process of DE 2039822 at similar concentrations of anthraquinones and in the temperature range indicated in the claims of the invention.
Since no liquid organic phase appears (see Example 13),
The mixture could no longer be stirred during the reaction. On the other hand, according to the method according to the invention, large amounts of anthraquinone can only be introduced if a liquid organic phase has already formed. Stirring in large amounts of anthraquinone is not difficult from a concentration point of view, since the anthraquinone is incorporated into the liquid organic phase and the liquid nature of the reaction mixture is completely preserved. The nitration in the process of the invention is likely an interfacial reaction. If the inorganic phase is separated off by suitable operations, for example by centrifugation, the reaction is immediately stopped, but the organic phase still contains a relatively large amount of nitric acid. After adding the separated inorganic phase or fresh sulfuric acid, the reaction starts again. Thus, good and thorough mixing of the two phases should be achieved during the reaction by vigorous stirring or other suitable methods. The formation of the liquid organic phase is probably due to the formation of anthraquinone/nitric acid addition products, especially those with a molar ratio of anthraquinone to nitric acid of 2:1 or 3:1. The composition of the phase during the reaction indicates this. At the stage of maximum de-mixing, which is the stage at which the organic liquid phase has an optimal liquid consistency, there is a significant A high nitric acid concentration was observed. The nitric acid in the inorganic phase becomes clearly concentrated again with the separation of the solid nitroanthraquinone (see Example 12) at the rate at which the liquid organic phase decomposes. During the separation of the liquid organic phase, the 1-nitroanthraquinone is obtained in a dense state so that, despite its high proportion of anthraquinone, the reaction mixture remains easily stirrable even in the final phase of the nitration. It is. However, due to the indications found in the description of the reaction process and the formation and decomposition of the liquid organic phase in the present invention, the method in the present invention is limited to the logic of the reaction process and the formation and decomposition of the liquid organic phase. It's not a thing. The above description is merely intended to serve to illustrate the method of the present invention and does not claim to be accurate in describing the reaction process and the production and decomposition of the liquid organic phase that takes place. In order to obtain a liquid organic phase during nitration in the present invention, certain nitration conditions need to be maintained. The proportion of anthraquinone in the nitration mixture should thus initially be at least 20% by weight, preferably at least 30% by weight. In the process of the invention, the weight ratio of nitric acid to sulfuric acid is initially from about 1:1 to about 2:1, such as from 1:1 to 2:1, preferably from 1.2:1 to 1.5:1. The weight ratio of nitric acid to anthraquinone in the process of the invention is initially about 0.5:1 to 1:1, e.g.
1, preferably 0.6:1 to 0.8:1. In the method of the invention, the weight ratio of sulfuric acid to water is initially from about 2.5:1 to about 5.5:1, such as from 2.5:1 to 5.5:1.
1, preferably 3.5:1 to 5.3:1. The above weight ratios refer to the total amount of all materials used. The process according to the invention is carried out at a temperature range of 45-70°C, preferably 48-60°C. Generally, the sulfuric acid used in the process of the invention is at a concentration in the range of 70-85% by weight, preferably 74-84% by weight, the total amount of water in the mixed acid is attributable to the sulfuric acid, and the nitric acid is in the range of 90-85% by weight.
It is used at a concentration of 100% by weight, preferably 97-99% by weight. These data, inter alia for concentrations and weight ratios, relate to the total amount of substances used; some of the amounts used may certainly lie outside the above ranges, for example mixed acids that contain small amounts of water or are anhydrous. is initially metered into the nitration mixture containing a high proportion of water, as described in Examples 10 _and 11, or at the beginning of the reaction, as described in Example 5, or at the beginning of the reaction _. Or when anthraquinone is gradually introduced into nitric acid. In order to obtain high yields of 1-nitroanthraquinone according to the process of the invention, it is advantageous to balance the measurements carried out with respect to each other in such a way that further nitration of the 1-nitroanthraquinone is largely avoided.
The appearance of a liquid organic phase also makes the reaction less sensitive to nitration reactions, but does not in principle prevent further nitration of mononitroanthraquinone to dinitroanthraquinone. Thus, for example, if the water content of the sulfuric acid is high and the proportion of anthraquinone is high in the nitration mixture, the weight ratio of nitric acid to sulfuric acid can shift more favorably to nitric acid. Further, for example, the reaction may be carried out (a) at a high weight ratio of nitric acid to sulfuric acid, with a specific weight ratio of sulfuric acid to water and a high weight ratio of sulfuric acid to anthraquinone; (b) at a low weight ratio of sulfuric acid to water; (c) by a specific weight ratio of sulfuric acid to anthraquinones and a high weight ratio of nitric acid to sulfuric acid; and (c) at a low weight ratio of sulfuric acid to water, a high weight ratio of nitric acid to sulfuric acid and a high weight ratio of sulfuric acid to anthraquinones. Therefore, it is advantageous to do so, and vice versa. The terms "high weight ratio" and "low weight ratio" refer to a high or low weight ratio, respectively, within the limits indicated in each case. In the process of the invention the temperature should not fall below 45°C, since there is a risk that the liquid organic phase will start to solidify and as the reaction progresses, the mixture will no longer be in a stirrable state. be. (See Example 1b). On the other hand, temperatures of 70° C., preferably 60° C. should not be exceeded, since at higher temperatures the rate of dinitroanthraquinone formation increases and/or anthraquinones and nitroanthraquinones decompose with oxygen. Because of the significant amount of heat released during the nitration reaction in the present invention, it is generally necessary to remove some or all of the heat of reaction, thus avoiding an excessive increase in temperature in the reaction mixture. This heat can be removed in any desired manner, e.g. by wall cooling with water, brine or vaporized ammonia, by evaporative cooling by distilling off excess nitric acid at reflux, preferably under reduced pressure, or by e.g. a curved reactor. External cooling of the sides of the reactor can be used to remove the reactor. After the anthraquinone content in the nitration mixture is less than 3% by weight, preferably about 2 to 3 parts by weight (in each case relative to the sum of the anthraquinone compounds), the reaction mixture is heated at a maximum temperature of 60° C. for up to 2 hours. The reaction time should be chosen such that the work-up is preferably less than 1 hour. Otherwise, dinitroanthraquinone would form to an appreciable extent and thus, despite the reduction in anthraquinone content,
No increase in yield of 1-nitroanthraquinone occurs. Generally the reaction time is between 2 and 7 hours, preferably 3 and 5 hours, and generally the time required is slightly longer for continuous methods than for discontinuous methods. For the process of the invention, at least 2 moles of nitric acid are required per mole of anthraquinone used. However, it is advantageous to use from 2.5 to 4 mol, preferably from 2.7 to 3.5 mol, of nitric acid per mole of anthraquinone used. The particle size of the anthraquinone used in the process of the invention is not critical because, on the one hand, relatively large anthraquinone particles are sufficiently nitrated in the liquid organic phase, and on the other hand, very fine anthraquinone particles make the reaction mixture particularly concentrated. This is to prevent it from becoming a problem. The method according to the invention is not as sensitive to changes in the sulfuric acid concentration as other methods, such as the method in DE-A-2039822. As a result of carrying out the process according to the invention at very high concentrations, the liberated reaction water leads to a reduction in the sulfuric acid concentration of up to 10% by weight during the reaction. At the end of the reaction, an acid concentration range is automatically obtained in which the nitric acid does not have any nitrating effect. For this reason also the change in the amount of nitric acid is not critical as in other methods. The method according to the invention can be carried out in various advantageous variants. The following variants may be mentioned as examples: Variant 1 In a mixed acid containing 60-80 parts by weight of sulfuric acid (100% by weight), 100-85 parts by weight of nitric acid (100% by weight) and 15-18 parts by weight of water. 100 parts by weight of anthraquinone are introduced at 48-52°C. Anthraquinone 3 in the nitration mixture
The nitration is carried out at a temperature of 50-60° C. until less than 50% by weight (with respect to the total amount of anthraquinone compounds) can be detected, and generally this involves approx.
It takes 5 hours. In this method, it is preferred to mix numerically relatively small amounts of H ₂ SO ₄ and water within the above ranges with numerically high values of HNO ₃ and vice versa. Variation 2 80-100 parts by weight of anthraquinone 72-78% by weight
100 to 150 parts by weight of sulfuric acid are introduced at 20 to 50°C, 80 to 110 parts by weight of nitric acid (98% by weight) are added, and then 100 to 120 parts by weight of anthraquinone and 35 to 45 parts by weight of sulfuric acid (100% by weight) are added. %, 120-150 parts by weight of a mixed acid consisting of 63-52% by weight of nitric acid (100% by weight) and 2-3% by weight of water are added simultaneously. 50 until less than 3% by weight of anthraquinone (relative to the total amount of anthraquinone compounds) can be detected in the nitration mixture.
Nitration is carried out at a temperature of ~60°C and generally takes 2 to 5 hours. In this method, it is preferred in each case to mix with one another values close to the first-mentioned number or close to the last-mentioned number within the indicated ranges. Variant 3 From crude 1-nitroanthraquinone (1-nitroanthraquinone content approximately 75%) 42-46% and nitric acid (100%) 38-40%, sulfuric acid (100%) 46-44% and water 14-16% 10-20% of the above reaction mixture having a composition of 54-58% of the mixed acid is retained. 9 to 4 times the amount of anthraquinone and the mixed acid were simultaneously introduced into the holding section of the above mixture over a period of 1 to 5 hours, and the amount of the mixed acid was 160 to 100 parts by weight per 100 parts by weight of the anthraquinone.
210 parts by weight is introduced, and the mixed acid is nitric acid (100%) 40~
35% by weight, 52-53% by weight of nitric acid (100%) and 8% by weight of water
Contains ~11% by weight. The nitration is carried out in the temperature range of 48 to 60 °C until less than 3% by weight of anthraquinone (based on the total amount of anthraquinone compounds) can be detected in the nitration mixture, which generally includes about 2 to 5% It takes time. In this method, within the range indicated in each case,
Preferably, values close to the first-mentioned number or values close to the last-mentioned number are mixed with each other. The process according to the invention can be carried out both batchwise and continuously; for example, a continuous process in which the process is carried out in reaction tubes or kettle cascades is particularly preferred. To obtain a high percentage of α-nitration,
It is advantageous to start the nitration at a temperature close to the lower limit, for example from 45 to 50°C, and to proceed at a higher temperature, for example from 55 to 65°C, if at least 75% of the anthraquinone has been nitrated. The reaction mixture can be worked up in a manner known per se, for example by metering the nitration mixture into water or by metering water into the nitration mixture,
A mixture of products precipitates out. The precipitate is suitably filtered or centrifuged, washed with a small amount of water until neutral, and then dried. If the nitration mixture is diluted with such an amount of water that the acid content of the mixture is below 50%, the nitroanthraquinone present and unreacted anthraquinone precipitates out almost completely. After separating these compounds,
A mixture of sulfuric and nitric acids containing a high proportion of water remains;
It is virtually free of organic components and salts. This mixture is advantageously separated into its components by distillation and reused for further nitration. In this process, the nitric acid and water can first be distilled until about 70% sulfuric acid remains in the bottom material, virtually free of nitric acid, which is then treated to concentrated acid, and the water is e.g. Distilled in a Plink apparatus. Also, first a quantity of concentrated sulfuric acid is added such that there is at least 70% acid with respect to nitric acid and water, and then the nitric acid is distilled from this as concentrated nitric acid, while the remaining bottom material consisting of sulfuric acid is e.g. Concentrate in a prink apparatus. Organic substances that may be present in the liquid obtained by separating the reaction products or in the centrifuged liquid are decomposed by oxidation during this type of acid regeneration. If the acid treatment is carried out according to the method described above, the nitric acid and sulfuric acid thus obtained are reused, and the wash water is used for diluting the nitration melt, as described in Example 3, then in the method of the invention: No eluent is obtained. As already mentioned, the nitration in the present invention is carried out when the anthraquinone content in the nitration mixture (based on the total amount of anthraquinone compounds) is 3.
% by weight, preferably ≦2. The necessary determination of the anthraquinone content in the nitration mixture can be carried out in a manner known per se. For example, analysis by quantitative thin layer chromatography or high performance liquid chromatography yields easily reproducible results, so that reaction times can be determined once for a given instrument condition, and other conditions are no longer continuous. There is no need to check. After processing the nitration mixture, in particular the nitration mixture obtained according to process variants 1 to 3, a mixture of products is obtained which contains at least 73% of 1-nitroanthraquinone and up to 3-4% of anthraquinone. , and a total of 10% or less, preferably 7% or less of 1,5- and 1,8-dinitroanthraquinone. Generally, the yield of 1-nitroanthraquinone is 74 to 80% of the theoretical yield calculated from the reaction formula based on the anthraquinone used. The method according to the invention has many advantages. Thus, compared to known processes, the nitration can be carried out with only small amounts of inorganic acids and the anthraquinone content in the nitration mixture can be more than 50%. Compared to, for example, the process in German Patent Application No. 2039822, which additionally requires considerably longer reaction times, the space/time yields can thus be several times higher. The method according to the invention is not particularly sensitive to changes in nitric acid and/or sulfuric acid concentration. As a result of carrying out the process at extremely high concentrations, the sulfuric acid concentration decreases by up to 10% during the process due to the liberation of the reaction water, so that at the end of the reaction, the acid concentration is such that nitric acid no longer has much of a nitrating effect. The range is automatically obtained.
In contrast, the nitric acid concentration in the process of DE 2039822, for example, has to be kept precisely because the free reaction water is due to the large excess of acid used. This is because it does not have a significant effect on concentration. According to Example 1 in German Patent Application Publication No. 2039822,
For example, a nitric acid concentration of 77.6% in the initial state and a sulfuric acid concentration of 76.9% in the final state are calculated. It is clear from this that in the process of DE 2039822, changes in the sulfuric acid concentration used have a greater effect on the reaction process than in the process of the invention. Also, the amount and concentration of HNO ₃ should be estimated more precisely. A further advantage of the process according to the invention is that the individual parameters can be matched to each other, so that the nitration rate can be kept constant over a long period of nitration, and the heat of reaction generated per unit time can be kept constant. remains almost constant and can be removed in a relatively simple way. Finally, it should be pointed out that in the process of the invention it is not necessary to use the anthraquinone in a particular form, for example in finely sieved form. The yield and purity of 1-nitroanthraquinone obtained according to the process of the invention is the same or better than in other processes. Generally by-products are
The total amount of 1,5- and 1,8-dinitroanthraquinone is less than 10%, generally less than 8%. As is known, 1-nitroanthraquinone is an important industrial intermediate product, which is e.g.
- can be used in the production of aminoanthraquinones, from which many anthraquinone dyes can be produced. The 1-nitroanthraquinone prepared according to the invention can be reduced directly to 1-aminoanthraquinone in known manner, for example by treatment with aqueous sodium sulfide solution. However, if a purer product is desired, it may be treated in known manner, for example with an aqueous sodium sulfite solution (U.S. Pat.
2302729) or by treatment with acid amides (see DE 2039822). Percentages in the following examples are by weight unless otherwise specified. If the content for inorganic acids or inorganic acid mixtures is given in %, 100%
What is needed is water. Example 1 a 150 g of the nitrated mixture containing 68 g of crude 1-nitroanthraquinone (see table below for composition) after completion of the reaction was added to a hook-type stirrer with a lid (diameter 9 cm) to which four tubes were fixed. , height 12
cm), a cylindrical reaction vessel (capacity 1.5, diameter 10 cm, height
20cm). To this mixture 500 g of industrial anthraquinone (99% purity) and the following composition: 351 g of H ₂ SO ₄ (100%), HNO ₃ (100%)
890 g of mixed acid of 464 g and 76.5 g of water at 48-50℃,
They were introduced uniformly and separately but simultaneously metered over a period of 3 hours at a stirring speed of 200 rpm. During this time, the temperature was adjusted to 49-51°C. After introducing 10-20% of the substance used, a two-phase system results,
This one showed a tendency towards great immiscibility. It consists of a high specific gravity transparent liquid inorganic phase consisting of a mixed acid with a small amount of anthraquinone or nitrated anthraquinone dissolved therein, and a low specific gravity completely or mainly liquid organic phase consisting of anthraquinone, nitroanthraquinone, nitric acid and a small amount of sulfuric acid. was. This two-phase system was maintained during the entire metering. After the end of the metering, the mixture was stirred for a further 1 hour at 50.degree. C. and finally for a further 3 hours at 60.degree.
During this process, the liquid organic phase gradually transferred to the solid phase with increasing nitration of anthraquinone, during which a continuous thickening of the mixture was observed;
However, easy stirring was maintained until the reaction was completed. During the reaction, a representative average sample of each (approximately 5 g) was removed with stirring, stirred in water, separated from the precipitate, washed with hot water until neutral, and dried. The dried samples were analyzed by high performance liquid chromatography. The results are shown in the table below. In this example, the weight ratio of nitric acid to sulfuric acid was 1.3:1, the weight ratio of sulfuric acid to anthraquinone was 0.7:1, and the weight ratio of sulfuric acid to water was 4.7:1. b. The method as described in b.a. was followed except that the method was carried out at 38-40°C. No liquid organic phase formed and the reaction mixture became very thick; after approximately half had been metered in, the mixture could no longer be stirred and the temperature could no longer be controlled. When the temperature was increased to 45 °C, the mass could be started to move with some difficulty; the mixture became stirrable again and weighed only when the temperature was increased further by 48-50 °C. As the introduction continued, a liquid organic phase formed.

[Table] Example 2 The same procedure as in Example 1 was carried out, except that the collection of each sample was omitted and the whole mixture was treated as follows: the mixture was stirred in cold water 5 and further heated at 60 °C. Stir for 1/2 hour, separate the precipitate, wash with hot water until neutral, and incubate under vacuum at 120°C.
Dry. The yield of the product thus obtained is 685
It was hot at g. Composition: Anthraquinone 1.9%, 1-
Nitroanthraquinone 73.9%, 2-nitroanthraquinone 8.0%, 1,6-dinitroanthraquinone 3.4%, 1,5-dinitroanthraquinone 3.6
%, 1,8-dinitroanthraquinone 3.2%,
1,7-dinitroanthraquinone 3.4%, 1,5
- dinitroanthraquinone 3.6%, 1,8-dinitroanthraquinone 3.4% and 2,6-+2,7
- Dinitroanthraquinone 0.2%. The yield of 1-nitroanthraquinone is 75% of the theoretical amount.
It was %. Example 3 Anthraquinone (99% purity) 10000 per hour
g and mixed acid (composition: HNO ₃ 100%) 52.1%, H ₂ SO ₄
(100%) 39.3% and H ₂ O 8.6%) 16,100 g with vigorous stirring, each element having a capacity of 35 and containing a filling screw, a mixed acid metering pump in cascade 1, a water metering pump in cascade 4, 48-50 in the first element of a 4-stage cascade (3-stage reaction cascade + dilution cascade) with water jackets capable of heating and cooling in cascades 1-4.
℃ and metered in at the same time. The obtained 1-nitroanthraquinone was washed with filtration solution 1 (approximately 18,900
g/h) were metered into cascade 4 at the same time. The temperatures in the individual elements of the cascade were adjusted as follows: cascade 1 48-50°C, cascade 2 54-56°C, cascade 3 59-61°C and cascade 4 58-62°C. The treatment was carried out by continuously filtering the effluent from cascade 4 through a rotary strainer and washing the material with water on the strainer at 60 DEG C. in two different zones. water per hour in the first zone
Add 17900g and use this method (cleaning solution 1) to make approximately 18900g
The liquid obtained in the amount of g/h was used for dilution in cascade 4. water per hour in the second zone
12400g was supplied. The solution obtained in this way (washing solution 2) could be fed to the biological treatment of the eluent. The material on the filter, which had been washed until neutral, was thoroughly dried under vacuum. 12550 g of product of the following composition were obtained per hour: anthraquinone 3.0%;
2-nitroanthraquinone 6.7%, 1-nitroanthraquinone 73.6%, 1,6-dinitroanthraquinone 4.0%, 1,7-dinitroanthraquinone
3.8%, 1,5-dinitroanthraquinone 3.8%,
1,8-dinitroanthraquinone 3.4%, 2,7
-+2,6-dinitroanthraquinone 0.6% and other substances 1.1%. The yield of 1-nitroanthraquinone is based on the theoretical amount
It was 75.9%. Treatment of the mother liquor by filtration on a rotary pressurizer was carried out in two variants. a. Known per se and “shot variant”
Nitric acid was distilled off as hydrous nitric acid by a method called (Schott variant). b By a method known per se and called "extractive distillation", anhydrous or 96% sulfuric acid is first added in such an amount that, with respect to water content versus sulfuric acid, 70% acid is present, and as concentrated nitric acid. Nitric acid was distilled off. Approx. remaining as distillation residue after step a or b
The 70% sulfuric acid was concentrated to 96% sulfuric acid in a manner known per se while distilling off the water in a so-called plinking apparatus. The acid thus obtained was fed back to the nitro chemical plant. In this example, the weight ratio of nitric acid to sulfuric acid was 1.3:1, the weight ratio of sulfuric acid to anthraquinone was 0.6:1, and the weight ratio of sulfuric acid to water was 4.6:1. Example 4 HNO ₃ was first introduced into a reactor as described in Example 1.
650 g of mixed acid consisting of 320 g of H ₂ SO ₄ (98%) and 330 g of H 2 SO 4 (78%) are introduced, and 500 g of anthraquinone are introduced with vigorous stirring for 5 minutes, starting at 25 °C and stopping at a temperature increase of 52-54 °C. did. The mixture was stirred for an additional hour at 50°C and for an additional 30 minutes at 60°C. _HNO3 (98%) at this temperature for 30 min.
Mixed acid 270 consisting of 150 g and 120 g of E ₂ SO ₄ (96%)
g was metered in and the mixture was heated again at 60°C for 2-3 hours.
Stirred for an additional hour. Approximately 10-15 minutes after introduction of the anthraquinone, a two-phase system consisting of the mixed acid and a fully or partially liquid organic phase is formed, which gradually decomposes after the mixed acid is added at 60°C, resulting in nitration of the solid. The anthraquinone was isolated. The reaction mixture was stirred in 4000 ml of water at 80°C.
Stir for 1/2 hour, filter the precipitate, wash the precipitate with water at 70° C. until neutral, and dry the precipitate. 625 g of dry product was obtained, which had the following composition: anthraquinone.
2.4%, 2-nitroanthraquinone 9.5%, 1-nitroanthraquinone 74.9%, 1,6-dinitroanthraquinone 2.4%, 1,7-dinitroanthraquinone 1.8%, 1.5-dinitroanthraquinone 3.1
%, 1,8-dinitroanthraquinone 2.9%,
2,6-+2,7-dinitroanthraquinone 0.4
% and other substances 2.6%. The yield of 1-nitroanthraquinone is 77% of the theoretical amount.
It was %. In this example, the weight ratio of nitric acid to sulfuric acid was 1.2:1, the weight ratio of sulfuric acid to anthraquinone was 0.8:1, and the weight ratio of sulfuric acid to water was 1.2:1.
It was 4.3:1. Example 5 The same procedure as Example 4 was carried out, except that the anthraquinone was introduced at a uniform rate over 1-2 hours. The metered introduction of the mixed acid, work-up and treatment were carried out as described in Example 4. 622 g of dry product containing 73.5% of 1-nitroanthraquinone were obtained. 1
- Yield of nitroanthraquinone is 74.9% of the theoretical amount
It was hot. Example 6 500 g of anthraquinone was added to H ₂ SO ₄ (100%) 315
The same procedure as in Example 1 was carried out, except that 400 g of HNO ₃ (100%) and 65.5 g of H ₂ O were metered into the mixed acid. The mixture was stirred at 50°C for 1 hour and at 60°C for a further 5 hours. After processing analogously to Example 2, 621 g of a 1-nitroanthraquinone mixture with the following composition were obtained: anthraquinone 2.0
%, 2-nitroanthraquinone 8.7%, 1-nitroanthraquinone 73.5%, 1,6-dinitroanthraquinone 3.4%, 1,7-dinitroanthraquinone 3.3%, 1,5-dinitroanthraquinone 3.4
%, 1,8-dinitroanthraquinone 3.0%,
2,6-+2,7-dinitroanthraquinone 0.6
% and other substances 2.1% The yield of 1-nitroanthraquinone is
It was 74.9%. In this example, the weight ratio of nitric acid to sulfuric acid is
The weight ratio of sulfuric acid to anthraquinone was 0.6:1, and the weight ratio of sulfuric acid to water was 4.8:1. Example 7 300 g of anthraquinone was stirred in 375 g of H ₂ SO ₄ (82%) and 420 g of HNO ₃ (98%) was stirred at 50-55 °C.
dripped over time. During this process, the initial thick mixture becomes more liquid after about 3/4 to 1 hour;
After 11/4 hours a liquid organic phase formed, which however still contained solid components. At this point, an additional 200 g of anthraquinone was added. After the addition of nitric acid had ended, the mixture was stirred at 50 °C for a further 1 h, warmed to 60 °C and at this temperature for 15 min.
43 g of monohydrate (=100% sulfuric acid) and HNO ₃ (98
%) 53g of the mixture was added. Finally add this mixture
The mixture was further stirred at 60°C for 2 hours. After stirring the reaction mixture in 3000 ml of water, separating off the precipitate, washing it to neutrality and drying, 627 g of a 1-nitroanthraquinone mixture with the following composition were obtained: 1.2% anthraquinone, 2-nitroanthraquinone. Anthraquinone 7.5%, 1-nitroanthraquinone
75.4%, 1,6-dinitroanthraquinone 3.4
%, 1,7-dinitroanthraquinone 3.2%,
1,5-dinitroanthraquinone 3.2%, 1,8
-dinitroanthraquinone 3.2%, and 2,6-
+2,7-dinitroanthraquinone 0.5%. The yield of 1-nitroanthraquinone is
It was 77.5%. In this example, the weight ratio of nitric acid to sulfuric acid was 1.3:1, the weight ratio of sulfuric acid to anthraquinone was 0.7:1, and the weight ratio of sulfuric acid to water was
The ratio was 4.7:1. Example 8 a After introducing the anthraquinone, the process was carried out under reduced pressure (approximately 70-100 mmHg) to evaporate excess nitric acid and the reactor was attached to the coolant at -20 °C.
The same procedure as in Example 4 was carried out, except that the brine was condensed in a high-intensity condenser fed and returned to the reaction mixture. Constant nitric acid distillation was ensured during the entire reaction. In contrast, the heat of the nitration reaction was initially sufficient: at the end of the reaction it was necessary to heat the reactor. After treatment, 1-nitroanthraquinone mixture
620g was obtained. The 1-nitroanthraquinone content is 73.8%;
It was 3.0%. The yield of 1-nitroanthraquinone was 75.2% of theory. b The method described in a was carried out, but heating of the reactor was omitted. As soon as the temperature of the reaction mixture fell below the desired temperature, it was returned to normal pressure and the reaction was completed as described in Example 4. Example 9 a The same procedure as in Example 4 was carried out, except that during the reaction the nitration mixture was circulated through a water-cooled Liebig condenser installed outside the reactor.
Also in this case the reaction temperature had to be increased. After treatment, 620 g of 1-nitroanthraquinone mixture were obtained. The 1-nitroanthraquinone content was 73.8% and the anthraquinone content was 2.9%. The yield of 1-nitroanthraquinone was 75.2% of the theoretical amount. b If the desired temperature or heat of reaction alone could not be maintained in the reactor, circulation could be omitted and the reaction completed as described in Example 4. Example 10 230 g of H ₂ SO ₄ (74%) are first introduced into a cylindrical reactor, in which 150 g of anthraquinone are stirred,
235 g of HNO ₃ (98%) was added dropwise over 1 hour. During this step the temperature rose to about 40°C. HNO ₃
430 g of a mixed acid consisting of 235 g (98%) and 195 g H ₂ SO ₄ (96%) were added at a uniform rate over a period of 2 hours. During this process, the temperature rose to 50-52°C. about 25
After adding % of the mixed acid, an emulsion was obtained, in which 350 g of anthraquinone was further stirred for 10 minutes. After the addition of the mixed acid was completed, the mixture was incubated at 50°C for 30 minutes and at 60°C for 30 minutes.
Stirred for an additional hour. The reaction mixture was then stirred in 4 ml of water, the precipitate was separated, the material on the separate vessel was washed with hot water until neutral, and dried. Thus, a 1-nitroanthraquinone mixture with the following composition:
615 g were obtained: 2.5% anthraquinone, 6.8% 2-nitrated anthraquinone, 75.9% 1-nitroanthraquinone, 3.0% 1,6-dinitroanthraquinone, 3.3% 1,7-dinitroanthraquinone.
%, 1,5-dinitroanthraquinone 3.7% and 1,8-dinitroanthraquinone 3.2%. The yield of 1-nitroanthraquinone is
It was 77.2%. In this example, the weight ratio of nitric acid to sulfuric acid was 1.3:1, the weight ratio of sulfuric acid to anthraquinone was 0.7:1, and the weight ratio of sulfuric acid to water was
The ratio was 4.6:1. Example 11 280 g of H ₂ SO ₄ (78%) are first introduced into a cylindrical reactor, in which 200 g of anthraquinone are stirred,
While stirring, 235 g of HNO ₃ (98%) was added dropwise over 30 minutes. During this step the temperature rose to 47°C. Next, 137 g of H ₂ SO ₄ (96%) and HNO ₃ (98
%) of the mixture was added at a uniform rate over 1 hour and 300 g of the anthraquinone was added at a uniform rate during the last 75% addition of the mixed acid. The temperature was maintained at 50-52°C during this step. The mixture was further stirred at 50°C for 1 hour and at 60°C for 2 hours. After working up as in Example 10, 619 g of a 1-nitroanthraquinone mixture were obtained with the following composition: 1.5% anthraquinone, 8.2% 2-nitroanthraquinone, 1-nitroanthraquinone.
Nitroanthraquinone 75.1%, 1,6-dinitroanthraquinone 3.0%, 1,7-dinitroanthraquinone 2.9%, 1,5-dinitroanthraquinone 3.7% and 1,8-dinitroanthraquinone 2.9
%. The yield of 1-nitroanthraquinone is based on the theoretical amount
It was 76.6%. In this example, the weight ratio of nitric acid to sulfuric acid was 1.3:1, the weight ratio of sulfuric acid to anthraquinone was 1.3:1, the weight ratio of sulfuric acid to anthraquinone was 0.7:1, and the weight ratio of sulfuric acid to water was 4.6:1. It was hot. Reference Example A 305 g of the reaction-completed mixture was introduced into a cylindrical reactor with a capacity of 2 and equipped with an outlet at the bottom.
600g anthraquinone and 501g sulfuric acid (84%)
and 595 g of HNO ₃ (98%), 50
They were introduced simultaneously over a period of 2 hours at ˜52° C. with vigorous stirring. Stir the mixture for an additional 20 minutes,
Then stirring was stopped. Two layers resulted. The water-clear bottom inorganic layer was separated from the top organic yellow liquid layer through the bottom outlet. After removing the interphase to eliminate incorrect values due to interfacial effects, 1007 g of organic phase remained. Approximately 1/10 of each of the two phases was diluted with such amount of water that all the anthraquinone compound precipitated. The mixture was then filtered, the residue washed with water until neutral, dried, and the liquid analyzed. From the dry weight of the residue and the analytical data it was possible to calculate the following composition of each phase: Inorganic phase: 455 g H ₂ SO ₄ , 232 g HNO ₃ , 31 g anthraquinones and 176 g water; Organic phase: H ₂ SO ₄ 61.3g, HNO ₃ 224g, anthraquinones 681g and water 41g. The weight ratio of sulfuric acid to nitric acid was 1.98:1 in the inorganic phase and 0.27:1 in the organic phase. B The procedure as described in A was carried out, except that after the introduction had ended, the mixture was further stirred at 50°C for 1 hour and at 60°C for 3 hours. The melt was diluted with an amount of water to precipitate all the anthraquinone compounds, the mixture was filtered, and the weight ratio of sulfuric acid to nitric acid in the liquid was determined analytically. The ratio is 1.33:1,
Compared to the inorganic phase with A, there was a clear preference for migration to the nitric acid side. 1990g of reaction mixture is
It contained 419 g of HNO ₃ , 558 g of H ₂ SO ₄ and 751 g of anthraquinones. Comparative example a: 500g of anthraquinone to 420g of H ₂ SO ₄ (84%)
Stir for 5 minutes in _a
Added for 10 minutes at °C. During this step, the temperature rose to 55°C and the mixture became almost viscous, just _barely stirrable;
When the addition was attempted, the melt became thick and could no longer be stirred. Despite intense cooling, the internal temperature of the melt rose to values above 55°C. This reaction could no longer be controlled. b Perform the method as described in a, but with the exception of 81.5%
_{H2SO4 was} used. In this case too, such severe thickening began with the addition of nitric acid, and the reaction mixture became unstirrable. c Perform the method as in a, but with the exception that
The weight of H ₂ SO ₄ was increased by 25%; again, after addition of about 160 g of HNO ₃ the melt could no longer be stirred. In all experiments a-c, no liquid organic phase appeared during the reaction.

Claims (1)

[Claims] 1. Anthraquinone in a nitric acid/sulfuric acid mixture,
The weight ratio of nitric acid to sulfuric acid is about 1:1 to about 2:1.
and the weight ratio of sulfuric acid to anthraquinone is approximately
0.5 to about 1:1 and a weight ratio of sulfuric acid to water of about 2.5:1 to about 5.5:1, where the weight ratio is based on the sum of the materials used, at a temperature range of 45 to 70°C. , mononitration of anthraquinone with a nitric acid/sulfuric acid mixture characterized by nitration until the anthraquinone content is 3% by weight or less with respect to the total anthraquinone compounds to produce 1-
A method of producing nitro-anthraquinone. 2. The method according to claim 1, wherein the nitration is carried out at a temperature range of 48 to 60°C. 3 Nitration at the initial stage of nitration from 45 to
The temperature range is 55℃, and after more than 50% of the anthraquinone used has been mononitrated, the temperature is lowered.
The method according to claim 1, wherein the temperature is increased to 55-70°C. 4 The weight ratio of nitric acid to sulfuric acid is
4. A process according to claim 1, which is carried out in a nitric acid/sulfuric acid mixture of 1.2:1 to 1.5:1. 5. Process according to any one of claims 1 to 4, in which the nitration is carried out in a nitric acid/sulfuric acid mixture at a weight ratio of sulfuric acid to anthraquinone of 0.6:1 to 0.8:1. 6 Weight ratio of sulfuric acid to water is 3.5:1 to 5.3:1
The method according to any one of claims 1 to 5. 7. Process according to any one of claims 1 to 6, in which all the nitric acid/sulfuric acid mixture is introduced first and then the anthraquinone is introduced therein. 8. Claims 1 to 8, in which the nitric acid/sulfuric acid mixture and the anthraquinone are metered separately but simultaneously into the completely or partially reacted mixture.
The method described in any of Section 6. 9. The process according to claim 1, wherein the steps are carried out in a multistage reaction cascade and the nitric acid/sulfuric acid mixture and the anthraquinone are metered in simultaneously into the first element of the reaction cascade in a continuous manner. . 10. The method according to any one of claims 1 to 6, wherein the nitric acid/sulfuric acid mixture and the anthraquinone are metered into the reaction tube in a continuous manner. 11 The indicated weight ratios are adjusted by first introducing sulfuric acid, water and a portion of anthraquinone, adding a portion of nitric acid until an emulsion of predominantly liquid organic and inorganic phases (H ₂ SO ₄ /HNO ₃ ) is formed; Then only the remaining anthraquinone, nitric acid, water and as needed
2. A method according to claim 1, wherein the setting is carried out by adding H ₂ SO ₄ . 12 In the initial mixture, the ratio H ₂ SO ₄ /anthraquinone is >1 and the ratio H ₂ SO ₄ /H ₂ O is <
3.6. The method of claim 11, wherein the method is: 13. The method according to claim 11 or 12, in which the remaining anthraquinone is added simultaneously with nitric acid and sulfuric acid or earlier than nitric acid and sulfuric acid.