1,2,4,5-tetracyanobenzene and a method for purifying the same

Abstract

The application discloses 1,2,4,5-tetracyanobenzene and a purification method thereof, and the purification method comprises the following steps: mixing 1,2,4,5-tetracyanobenzene crude product and a good solvent to obtain a mixed solution, and standing the mixed solution at 20-25 DEG C to volatilize the good solvent and obtain 1,2,4,5-tetracyanobenzene crystals; the good solvent is an ether aromatic hydrocarbon; the 1,2,4,5-tetracyanobenzene crystals are washed by a poor solvent, and then subjected to solid-liquid separation to obtain solid phase substances; the poor solvent comprises one or more than two of anhydrous ethanol, n-hexane, n-pentane, n-heptane and acetone; and the solid phase substances are dried to obtain 1,2,4,5-tetracyanobenzene pure product. The good solvent and the poor solvent are matched with each other, the problem of difficult rapid purification is solved, the overall process is short, solvent consumption is low, cost is low, yield is high, purity can reach 99%, and the demand of high-tech industry can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of 1,2,4,5-tetracyanobenzene, and more particularly to 1,2,4,5-tetracyanobenzene and a purification method thereof. Background Art

[0002] 1,2,4,5-Tetracyanobenzene is a versatile organic compound that can be used as an intermediate in drug synthesis, a dye raw material, and in the electronics industry to produce organic semiconductors. Its structure is shown below:

[0003]

[0004] Purity requirements for 1,2,4,5-tetracyanobenzene have increased significantly with production needs. Substandard purity can lead to equipment failure, unstable performance, increased manufacturing costs, and reduced product quality in the fields of high-quality electronic components, precision medical devices, high-performance polymer materials, and advanced pharmaceuticals produced using 1,2,4,5-tetracyanobenzene as a raw material.

[0005] However, no existing technology has disclosed an effective method for purifying 1,2,4,5-tetracyanobenzene. Furthermore, conventional purification methods typically employ recrystallization, solvent extraction, and column chromatography. Improper handling during the purification process can lead to product decomposition or loss, resulting in a decrease in the yield of the purified product. Furthermore, these methods can also leave residual harmful impurities, reducing the quality and practicality of the purified product. Furthermore, the cumbersome purification steps, expensive purification equipment, and high solvent consumption not only increase costs but also have adverse environmental impacts. Summary of the Invention

[0006] The present invention aims to overcome the above-mentioned defects of the prior art and provide 1,2,4,5-tetracyanobenzene and a purification method thereof. By using a good solvent and a poor solvent in combination, the problem of difficulty in rapid purification is solved. The overall process is short, solvent consumption is low, cost is low, and yield is high. The purity of the purified 1,2,4,5-tetracyanobenzene can reach 99%, which can meet the needs of high-tech industries.

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] A method for purifying 1,2,4,5-tetracyanobenzene comprises the following steps:

[0009] Mixing crude 1,2,4,5-tetracyanobenzene and a good solvent to obtain a mixed solution, and allowing the mixed solution to stand at 20° C. to 25° C. to volatilize the good solvent to obtain 1,2,4,5-tetracyanobenzene crystals; the good solvent is an ether aromatic hydrocarbon;

[0010] washing the 1,2,4,5-tetracyanobenzene crystals with a poor solvent and then performing solid-liquid separation to obtain a solid phase; the poor solvent comprises one or more of anhydrous ethanol, n-hexane, n-pentane, n-heptane and acetone;

[0011] The solid phase was dried to obtain pure 1,2,4,5-tetracyanobenzene.

[0012] The present invention also discloses 1,2,4,5-tetracyanobenzene, which is obtained by purifying the 1,2,4,5-tetracyanobenzene according to any one of claims 1 to 9.

[0013] The implementation of the present invention will have the following beneficial effects:

[0014] The invention provides an efficient, environmentally friendly and economical method for purifying 1,2,4,5-tetracyanobenzene. According to the different solubilities of 1,2,4,5-tetracyanobenzene in different solvents, 1,2,4,5-tetracyanobenzene is firstly dissolved in an ether aromatic hydrocarbon good solvent with relatively high solubility for the 1,2,4,5-tetracyanobenzene, and charge transfer interaction is generated between the ether aromatic hydrocarbon good solvent and the 1,2,4,5-tetracyanobenzene according to the solvent effect. The ether aromatic hydrocarbon good solvent is allowed to stand and evaporate to obtain 1,2,4,5-tetracyanobenzene crystals. Then, another poor solvent with relatively low solubility for the 1,2,4,5-tetracyanobenzene is used to wash the 1,2,4,5-tetracyanobenzene, and the residual good solvent is further removed. The 1,2,4,5-tetracyanobenzene is subjected to solid-liquid separation and drying, thereby achieving rapid purification of the 1,2,4,5-tetracyanobenzene.

[0015] In summary, the purification method of the present invention adopts a good solvent and a poor solvent to cooperate with each other, overcomes the limitations of the prior art, solves the problem that 1,2,4,5-tetracyanobenzene is difficult to purify quickly, avoids high equipment and cost investment, only needs to be dissolved once, left to volatilize, washed, separated and dried, the overall process is short, solvent consumption is low, cost is low, and no repeated treatment is required. The yield of 1,2,4,5-tetracyanobenzene is high, and it has the advantages of energy saving and environmental protection, simplicity and high efficiency, high operability, applicability to different production scales, and ease of industrial production. The purity of the purified 1,2,4,5-tetracyanobenzene can reach 99%, which can meet the demand of high-tech industries for high-purity 1,2,4,5-tetracyanobenzene, and help improve product performance in the fields of electronic components, medical equipment, polymer materials and drugs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the HPLC spectrum of the crude 1,2,4,5-tetracyanobenzene of Comparative Example 1 at 294 nm that was not purified by the purification method of the present invention.

[0017] Figure 2This is the HPLC spectrum of the pure 1,2,4,5-tetracyanobenzene obtained in Example 1 at 294 nm.

[0018] Figure 3 This is the HPLC spectrum of the pure 1,2,4,5-tetracyanobenzene obtained in Example 2 at 294 nm.

[0019] Figure 4 This is the HPLC spectrum of the pure 1,2,4,5-tetracyanobenzene obtained in Example 3 at 294 nm.

[0020] Figure 5 This is the TG spectrum of 1,2,4,5-tetracyanobenzene in Comparative Example 1 that was not purified by the purification method of the present invention.

[0021] Figure 6 This is the TG spectrum of the pure 1,2,4,5-tetracyanobenzene obtained in Example 1. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to specific examples, but the present invention is not limited thereto in any way.

[0023] The present invention discloses a method for purifying 1,2,4,5-tetracyanobenzene, comprising the following steps:

[0024] 1) A crude 1,2,4,5-tetracyanobenzene product and a good solvent are mixed to obtain a mixed solution, and the mixed solution is allowed to stand at 20° C. to 25° C. to allow the good solvent to evaporate, thereby obtaining 1,2,4,5-tetracyanobenzene crystals; the good solvent is an ether aromatic hydrocarbon.

[0025] Specifically, the crude 1,2,4,5-tetracyanobenzene is first dissolved in an ether aromatic hydrocarbon good solvent with relatively high solubility, and a charge transfer interaction is generated between the solvent and the 1,2,4,5-tetracyanobenzene. The ether aromatic hydrocarbon good solvent is allowed to evaporate, thereby obtaining 1,2,4,5-tetracyanobenzene crystals.

[0026] In a specific embodiment, the crude 1,2,4,5-tetracyanobenzene is any crude 1,2,4,5-tetracyanobenzene that has not been purified by the purification method of the present invention, including products purchased from the market and products prepared by existing methods.

[0027] In one embodiment, step 1) specifically includes the following steps: ultrasonically vibrating the crude 1,2,4,5-tetracyanobenzene and a good solvent at 20°C to 25°C for 5 to 10 minutes, then covering the mouth of the bottle containing the mixed solution with plastic wrap, puncturing the plastic wrap at the bottle mouth, and placing the bottle on a platform at 20°C to 25°C to allow the good solvent to evaporate. Specifically, by setting the mixing temperature to this level, the dissolution rate of the crude 1,2,4,5-tetracyanobenzene can be increased while ensuring energy conservation, environmental protection, simplicity, efficiency, and high operability.

[0028] In one specific embodiment, when the amount of the added good solvent is too small, a portion of the crude 1,2,4,5-tetracyanobenzene does not dissolve but exists as a solid, resulting in incomplete removal of impurities. On the contrary, when the amount of the added good solvent is too large, it leads to an extension of the standing time and the subsequent washing cost in step 2). Therefore, the molar ratio of the crude 1,2,4,5-tetracyanobenzene to the good solvent is 1:(10-20).

[0029] In one embodiment, the standing time is preferably 4 to 5 hours. This is because during the volatilization of the good solvent, 1,2,4,5-tetracyanobenzene forms fine crystals. If the standing time is insufficient, the fine 1,2,4,5-tetracyanobenzene crystals cannot agglomerate into large crystals and are easily filtered out, thereby reducing the yield. Furthermore, by controlling the standing temperature at 20°C to 25°C during the standing time, the 1,2,4,5-tetracyanobenzene crystals can be fully precipitated.

[0030] In a specific embodiment, the "good solvent" in the purification method provided by the present invention refers to a solvent that has a strong solubility for the crude 1,2,4,5-tetracyanobenzene.

[0031] In a specific embodiment, the good solvent includes one or more of 1,3-dimethoxybenzene, p-methylanisole, and m-methylanisole.

[0032] 2) washing the 1,2,4,5-tetracyanobenzene crystals with a poor solvent and then performing solid-liquid separation to obtain a solid phase; the poor solvent comprises one or more of anhydrous ethanol, n-hexane, n-pentane, n-heptane and acetone.

[0033] Specifically, another poor solvent with low solubility for 1,2,4,5-tetracyanobenzene is used to wash it, and the 1,2,4,5-tetracyanobenzene crystals are uniformly dispersed in the poor solvent to form a uniform suspension. The obtained suspension is then subjected to solid-liquid separation to obtain a solid phase, and the 1,2,4,5-tetracyanobenzene crystals are separated from the poor solvent. In this step, the residual good solvent is removed along with the filtrate.

[0034] In a specific embodiment, step 2) specifically includes the following steps: ultrasonically treating the 1,2,4,5-tetracyanobenzene crystals obtained after standing at 20° C. to 25° C. with a poor solvent for 5 to 10 minutes, and then performing solid-liquid separation to obtain a solid phase.

[0035] In one specific embodiment, the molar ratio of 1,2,4,5-tetracyanobenzene crystals to the poor solvent is 1:(10-20). By controlling the feed ratio of 1,2,4,5-tetracyanobenzene crystals to the poor solvent, the residual good solvent can be fully dissolved in the poor solvent, and the 1,2,4,5-tetracyanobenzene crystals can be fully precipitated, thereby improving the yield. However, when the proportion of the poor solvent is too high, the cost of subsequent solvent recovery and separation needs to be increased.

[0036] 3) Drying the solid phase to obtain pure 1,2,4,5-tetracyanobenzene.

[0037] Specifically, the solid phase obtained by solid-liquid separation is dried, thereby achieving rapid purification of 1,2,4,5-tetracyanobenzene.

[0038] In one embodiment, step 3) specifically includes the following steps: placing the product in a vacuum drying oven, heating it to 40°C to 50°C, and drying it for 5 to 10 minutes to obtain pure 1,2,4,5-tetracyanobenzene. Specifically, the drying temperature is regulated to avoid excessively low temperatures, which may result in residual solvent, and excessively high temperatures, which may waste energy.

[0039] The invention provides an efficient, environmentally friendly and economical method for purifying 1,2,4,5-tetracyanobenzene. According to the different solubilities of 1,2,4,5-tetracyanobenzene in different solvents, a good solvent and a poor solvent are used in combination with each other, thereby overcoming the limitations of the prior art, solving the problem that 1,2,4,5-tetracyanobenzene is difficult to purify quickly, and avoiding high equipment and cost investment. Only one dissolution, standing for volatilization, washing, separation and drying are required, and the overall process is short, solvent consumption is low, cost is low, and repeated multiple treatments are unnecessary. The yield of 1,2,4,5-tetracyanobenzene is high, and the method has the advantages of energy saving and environmental protection, simplicity and high efficiency, high operability, applicability to different production scales, and ease of industrial production.

[0040] In one specific embodiment, pure 1,2,4,5-tetracyanobenzene is activated by heating to remove solvent molecules. In one specific embodiment, the activation temperature is 30°C to 40°C, and the activation time is 0.5 to 2 hours. Specifically, the activated pure 1,2,4,5-tetracyanobenzene can be directly used in the production of high-quality electronic components, precision medical devices, high-performance polymer materials, and advanced pharmaceuticals.

[0041] The present invention also discloses 1,2,4,5-tetracyanobenzene, which is obtained by purifying the 1,2,4,5-tetracyanobenzene using the purification method for 1,2,4,5-tetracyanobenzene according to any embodiment of the present invention. Specifically, the purity of the pure 1,2,4,5-tetracyanobenzene obtained by the purification method provided in any embodiment of the present invention can reach 99%, which can meet the demand for high-purity 1,2,4,5-tetracyanobenzene in high-tech industries and help improve the performance of products in fields such as electronic components, medical devices, polymer materials, and pharmaceuticals.

[0042] The following are specific embodiments

[0043] Example 1

[0044] The purification method of 1,2,4,5-tetracyanobenzene of the present embodiment comprises the following steps:

[0045] 1) Crude 1,2,4,5-tetracyanobenzene and 1,3-dimethoxybenzene were placed in a flask at a molar ratio of 1:10 and ultrasonically vibrated at 25°C for 8 minutes. The bottle mouth containing the mixed solution was then covered with plastic wrap, and the plastic wrap at the bottle mouth was pierced. The bottle was then placed on a platform and allowed to stand at 25°C for 5 hours to allow 1,3-dimethoxybenzene to evaporate.

[0046] 2) The 1,2,4,5-tetracyanobenzene crystals obtained after standing were ultrasonically treated with anhydrous ethanol at 25° C. for 10 minutes, wherein the molar ratio of the 1,2,4,5-tetracyanobenzene crystals to the anhydrous ethanol was 1:10, and solid-liquid separation was performed to obtain a solid phase.

[0047] 3) The solid phase was placed in a vacuum drying oven, heated to 50° C., and dried for 10 min to obtain pure 1,2,4,5-tetracyanobenzene. The yield of the final product in this example was tested to be 97%.

[0048] Example 2

[0049] The only difference between this embodiment and the embodiment is that p-methylanisole is used as the good solvent. According to the purification method of embodiment 1, pure 1,2,4,5-tetracyanobenzene is obtained. The yield of the final product obtained in this embodiment is 96%.

[0050] Example 3

[0051] The only difference between this embodiment and embodiment 1 is that m-methylanisole is used as the good solvent. According to the purification method of embodiment 1, pure 1,2,4,5-tetracyanobenzene is obtained. The yield of the final product obtained in this embodiment is 93%.

[0052] Comparative Example 1

[0053] This comparative example uses crude 1,2,4,5-tetracyanobenzene that has not been purified by the purification method of the present invention.

[0054] Test Case

[0055] The pure 1,2,4,5-tetracyanobenzene obtained in Examples 1-3 and the crude 1,2,4,5-tetracyanobenzene obtained in Comparative Example 1 but not purified by the purification method of the present invention were separated by chiral high performance liquid chromatography (HPLC). The chromatographic column was CHIRALPAK IA (IA00CE-VD015), the mobile phase was MeOH / CH2Cl2=70 / 30, the flow rate was 1.0 mL / min, the column temperature was 35°C, and the UV detector was 254 nm. The test results are shown in FIG. Figure 1-4 , Figure 1-4 HPLC spectra at 294 nm of the crude 1,2,4,5-tetracyanobenzene obtained in Comparative Example 1 and the pure 1,2,4,5-tetracyanobenzene obtained in Examples 1-3 are shown respectively.

[0056] Figure 1-4 The test data show that the 1,2,4,5-tetracyanobenzene of Comparative Example 1, which was not purified by the purification method of the present invention, showed a clear absorption peak at 1.8 min and an impurity peak at 2.2 min. The HPLC spectrum showed that its purity was 97.8%. In Example 1, in which 1,3-dimethoxybenzene was used as a good solvent, the purified 1,2,4,5-tetracyanobenzene showed a clear absorption peak at 1.8 min and an impurity peak at 2.2 min. The HPLC spectrum showed that its purity was 99.7%. In Example 2, in which p-methylanisole was used as a good solvent, the purified 1,2,4,5-tetracyanobenzene showed a clear absorption peak at 1.8 min and an impurity peak at 2.2 min. The HPLC spectrum showed that its purity was 99.3%. In Example 3, where m-methylanisole was used as a good solvent, the purified 1,2,4,5-tetracyanobenzene showed a clear absorption peak at 1.8 min and an impurity peak at 2.2 min. The HPLC spectrum showed that the purity was 99.4%.

[0057] The pure 1,2,4,5-tetracyanobenzene obtained in Examples 1-3 and the crude 1,2,4,5-tetracyanobenzene not purified by the purification method of the present invention were subjected to TG detection. The test results are as follows: Figure 5-6 As shown, Figure 5 is the TG spectrum of 1,2,4,5-tetracyanobenzene that has not been purified by the purification method of the present invention, Figure 6 This is the TG spectrum of the pure 1,2,4,5-tetracyanobenzene obtained in Example 1.

[0058] Figure 5-6The test data show that 1,2,4,5-tetracyanobenzene that has not been purified by the purification method of the present invention contains impurities that are difficult to vaporize, while the impurity mass in the pure 1,2,4,5-tetracyanobenzene obtained by the purification method of the present invention is close to zero.

[0059] According to the test results, the present invention provides an efficient, environmentally friendly, and economical method for purifying 1,2,4,5-tetracyanobenzene. The purification method of the present invention utilizes a good solvent and a poor solvent in combination to overcome the limitations of the prior art, solve the problem of difficulty in rapidly purifying 1,2,4,5-tetracyanobenzene, and avoids high equipment and cost investment. Only one step of dissolution, standing for volatilization, washing, separation, and drying is required, thereby achieving rapid purification of 1,2,4,5-tetracyanobenzene. The overall process is short, solvent consumption is low, and cost is low. No repeated treatment is required, the yield of 1,2,4,5-tetracyanobenzene is high, and the purity of the purified 1,2,4,5-tetracyanobenzene can reach 99%. The method can meet the needs of high-tech industries for high-purity 1,2,4,5-tetracyanobenzene and contribute to improving product performance in the fields of electronic components, medical equipment, polymer materials, and pharmaceuticals.

[0060] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for purifying 1,2,4,5-tetracyanobenzene, characterized in that: The following steps are involved: Mixing a crude 1,2,4,5-tetracyanobenzene product and a good solvent to obtain a mixed solution, and allowing the mixed solution to stand at 20° C. to 25° C. to volatilize the good solvent to obtain 1,2,4,5-tetracyanobenzene crystals; the good solvent is one or more of 1,3-dimethoxybenzene, p-methylanisole, and m-methylanisole; washing the 1,2,4,5-tetracyanobenzene crystals with a poor solvent and then performing solid-liquid separation to obtain a solid phase; the poor solvent is one or more of anhydrous ethanol, n-hexane, n-pentane, n-heptane and acetone; The solid phase was dried to obtain pure 1,2,4,5-tetracyanobenzene.

2. The method for purifying 1,2,4,5-tetracyanobenzene according to claim 1, wherein The molar ratio of the crude 1,2,4,5-tetracyanobenzene to the good solvent is 1:(10-20); The molar ratio of the 1,2,4,5-tetracyanobenzene crystals to the poor solvent is 1:(10-20).

3. The method for purifying 1,2,4,5-tetracyanobenzene according to claim 1, characterized in that The mixing temperature is 20°C to 25°C; The mixing time is 5 min to 10 min.

4. The method for purifying 1,2,4,5-tetracyanobenzene according to claim 1, wherein The standing time is 4h~5h.

5. The method for purifying 1,2,4,5-tetracyanobenzene according to claim 1, characterized in that: The washing temperature is 20°C to 25°C; The washing time is 5 min to 10 min.

6. The method for purifying 1,2,4,5-tetracyanobenzene according to claim 1, characterized in that: The drying temperature is 40°C to 50°C; The drying time is 5 min to 10 min.

7. The method for purifying 1,2,4,5-tetracyanobenzene according to claim 1, characterized in that: The pure 1,2,4,5-tetracyanobenzene is activated by heating to remove solvent molecules.

8. The method for purifying 1,2,4,5-tetracyanobenzene according to claim 7, wherein The activation temperature is 30°C to 40°C; The activation time is 0.5h~2h.

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