Ethylhexyl triazone products and methods for their preparation

Abstract

This invention relates to the field of fine chemical technology, specifically to an ethylhexyl triazine ketone product and its preparation method, comprising the following steps: using cyanuric chloride and isooctyl p-aminobenzoate as raw materials, reacting to generate crude ethylhexyl triazine ketone; and then crystallizing the crude ethylhexyl triazine ketone under alkaline conditions with a pH value ≤ 10. This invention, by crystallizing the crude ethylhexyl triazine ketone under alkaline conditions, significantly reduces the precipitation of impurities H and B during the cooling crystallization process, yielding an ethylhexyl triazine ketone product with an impurity H content below 0.03 wt% and an impurity B content below 0.05 wt%, which is beneficial for its subsequent application in sunscreens.

Description

Technical Field

[0001] This invention relates to the field of fine chemical technology, and in particular to an ethylhexyltriazine ketone product and its preparation method. Background Technology

[0002] EHT (CAS: 88122-99-0, ethylhexyltriazinone, structural formula as follows) Figure 1 (As shown) is a new type of ultraviolet absorber that has been developed in recent years. It belongs to the ethylhexyl triazine ketone product category. It has a large molecular structure, high ultraviolet absorption efficiency and broad-spectrum sun protection effect. It is not only the oil-soluble absorber with the strongest UVB absorption capacity, but also protects against UVA ultraviolet rays. It has strong photostability and water resistance, and has good affinity for the keratin of the skin. It can be used as an additive in sunscreen products.

[0003] The simplified production process of EHT is as follows: cyanuric chloride and isooctyl p-aminobenzoate are reacted under micro-reflux in xylene. After the reaction, the mixture is washed with water to separate the layers, then the xylene is removed by distillation, and crude crystals are obtained by adding ethanol at high temperature. However, during the reaction of cyanuric chloride and isooctyl p-aminobenzoate to produce EHT, cyanuric chloride deteriorates upon contact with water and reacts with isooctyl p-aminobenzoate to produce impurities H1 and H2, as shown below. These impurities have poor solubility. Additionally, EHT hydrolyzes upon contact with water during the reaction, easily producing EHT-related impurity B.

[0004]

[0005]

[0006] These two impurities are the two most significant impurities in existing processes, causing turbidity in the product solution and failing to be effectively removed after purification, easily leading to excessive levels of single impurities and product solubility problems. In the production of sunscreens, various esters are commonly used as solvents, such as ethyl acetate and OS (isooctyl salicylate CAS: 118-60-5). Studies have found that when the total content of impurities H1 and H2 is below 0.08%, EHT can dissolve completely in ethyl acetate, but this is still insufficient for the finished product to dissolve completely in OS. Research indicates that the total content of impurities H1 and H2 needs to be controlled to less than 0.03% for the product to dissolve completely in OS. Therefore, how to remove impurities H1, H2, and B from ethylhexyl triazine ketone products is an urgent problem to be solved.

[0007] In view of this, it is necessary to provide an improved ethylhexyltriazine ketone product and its preparation method to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to provide an ethylhexyltriazine ketone product and its preparation method, which significantly reduces the content of impurities H and B by crystallization under alkaline conditions with a pH value ≤10, thereby improving its safety and solubility.

[0009] To achieve the above objectives, the present invention provides a method for preparing an ethylhexyl triazine ketone product, comprising the following steps:

[0010] Crude ethylhexyl triazine ketone was produced by reacting cyanuric chloride and isooctyl p-aminobenzoate as raw materials.

[0011] The crude ethylhexyltriazine was then crystallized under alkaline conditions with a pH ≤ 10, achieved by adding an organic base and / or an inorganic base. This method significantly reduces the content of impurities H and B. Impurity B is an FDA pharmacopoeia standard, and impurity H includes isomers H1 and H2, the structures of which can be determined using NMR and mass spectrometry. The structures of impurities H1, H2, and B are shown below:

[0012]

[0013] In the investigation of the EHT crystallization process of this invention, it was found that acidic crystallization and crystallization at 30°C were more effective at removing impurities H1 and H2 than normal crystallization. Impurities H1 and H2 could be dissolved in OS, but the content of impurity B would increase, and direct acid washing would significantly reduce the yield (by about 10%). Further research revealed that crystallization under alkaline conditions could not reduce the yield while having a better impurity removal effect, with the best effect on removing impurities H1 and H2. At the same time, since the carboxylic acid functional groups contained in impurity B were neutralized under alkaline conditions, impurity B could also be removed during the crystallization process.

[0014] Furthermore, this invention has found that excessive alkali addition, excessively high temperature, or excessively long filtration time can easily lead to the formation of other impurities. Insufficient alkali addition or insufficient stirring time will prevent the solubility from meeting the required standards. The amount of organic and / or inorganic alkali added is 0.1% to 0.4% of the crude ethylhexyl triazine ketone, preferably 0.1% to 0.2%, more preferably 0.15%, and the pH of the solution is controlled to be ≤10, preferably 8-10, more preferably 8-9. The organic and / or inorganic alkalis of this invention include alkalis that do not completely ionize after dissolving in water and salts that ionize to form alkaline solutions (strong base weak acid salts). Selecting weak alkalis and strictly controlling the amount added can prevent the decomposition of EHT due to excessive alkalinity, which could lead to the formation of new impurities.

[0015] The crude ethylhexyltriazine ketone is in a molten and / or dissolved state in a hot solution. By filtration, some impurities that are insoluble in the hot solution are first removed. Then, the filtrate is cooled, and the crude ethylhexyltriazine ketone gradually crystallizes out, while impurities H1, H2 and B remain in a dissolved state, thereby effectively removing impurities H1, H2 and B.

[0016] Furthermore, the organic base includes one or more of triethylamine, diethylamine, triethanolamine, acetate, and formate; the inorganic base includes one or more of carbonate, bicarbonate, and ammonia, preferably carbonate, bicarbonate, ammonia, acetate, and formate. In experiments, using organic bases such as triethylamine, diethylamine, and triethanolamine for alkaline crystallization achieves good impurity removal, thus solving the solubility problem. However, some organic base residue remains in the finished product, resulting in a noticeable amine odor. Therefore, based on practical application needs, to overcome the amine odor problem, non-organic amine substances can be used for alkaline crystallization, thus solving both the odor and solubility problems without producing any odor issues.

[0017] Furthermore, the crude ethylhexyltriazine ketone is mixed with an alkaline solution at 55-70°C, preferably 58-68°C, and more preferably 62°C. After hot filtration, it is cooled and crystallized under alkaline conditions with a pH ≤ 10. Excessive temperature may cause the crude ethylhexyltriazine ketone to decompose and generate new impurities, while excessively low temperature will affect the melting or dissolution state of the crude ethylhexyltriazine ketone in the hot solution, thereby encapsulating impurities H1, H2, and B, and reducing the impurity removal effect.

[0018] The crude ethylhexyltriazine is mixed with a filter aid, and then mixed with an alkaline solution and filter aid at 55-70°C. After hot filtration, the mixture is cooled and crystallized under alkaline conditions with a pH ≤ 10. The amount of filter aid added is 1.2-2 times the mass of the weak base, preferably 1.3-1.6 times, and more preferably 1.5 times. The filter aid increases the filtration speed and prevents the generation of other impurities due to excessive filtration time; at the same time, the filter aid can also prevent filter clogging caused by undissolved alkaline components.

[0019] Furthermore, the filter aid includes one or more of diatomaceous earth, perlite, cellulose, asbestos, graphite powder, sawdust, magnesium oxide, gypsum, activated carbon, and acid clay, preferably diatomaceous earth.

[0020] Further, the crude ethylhexyltriazine is dissolved and refluxed in an alcohol solvent, then cooled to 55-70°C, an organic base and / or an inorganic base and a filter aid are added, the pH value is controlled to be ≤10, the mixture is stirred for 1-4 hours, then filtered while hot, and then cooled to crystallize to obtain the ethylhexyltriazine product.

[0021] Furthermore, the amount of alcohol solvent added is 2-4 times the mass of the crude ethylhexyltriazine, preferably 2-3 times, more preferably 2.5 times; and / or, the alcohol solvent includes one or more of ethanol, isopropanol and butanol, preferably ethanol.

[0022] In a preferred embodiment, when using an inorganic base, adding 1-5% by volume of water to the alcohol solvent can improve the solubility of the base, thereby increasing the solubility of impurities H1, H2, and B and reducing the amount of impurities precipitated during crystallization. Alternatively, an inorganic base solution can be added to the crude ethylhexyl triazine ketone solution after reflux dissolution. Preferably, the water content in the system does not exceed 10%, and more preferably does not exceed 5%.

[0023] Furthermore, the stirring time is preferably 1.5-2.5h, more preferably 2h; the cooling rate for the cooling crystallization is 10-15℃ / h, and the crystallization temperature is 0-5℃.

[0024] Appropriate stirring time is beneficial for improving the solubility of H1, H2, and B, while preventing the formation of new impurities and improving separation efficiency. This invention optimizes the purification process by controlling the stirring dissolution temperature, stirring time, cooling rate, and crystallization temperature.

[0025] This invention explores methods for removing impurities H1, H2, and B generated during the EHT synthesis reaction. It investigates an effective method for dissolving impurities H1, H2, and B in a weakly alkaline solution and crystallizing the EHT product, thereby removing these impurities. Through experimental analysis, the technical solutions regarding the amount of alkali added, temperature, alcohol solvent, and filter aid selection were optimized, ultimately resulting in the aforementioned optimized scheme. This method yields an ethylhexyltriazine ketone product with impurity H content below 0.03 wt% and impurity B content below 0.05 wt%.

[0026] The present invention also provides an ethylhexyltriazine ketone product, which is prepared by any of the methods described above.

[0027] Preferably, the content of impurity H in the ethylhexyl triazine ketone product is less than 0.03 wt%; the impurity H is impurity H1 and / or H2 with the following structures:

[0028]

[0029] Preferably, the content of impurity B in the ethylhexyl triazine ketone product is less than 0.05 wt%; the structure of impurity B is shown below:

[0030]

[0031] The beneficial effects of this invention are as follows:

[0032] 1. The preparation method of ethylhexyl triazine ketone provided by the present invention involves filtering and crystallizing crude ethylhexyl triazine ketone under alkaline conditions while hot, thereby significantly reducing the content of impurities H1, H2 and B, and improving its safety and solubility.

[0033] 2. The present invention also improves the purification efficiency by adding a small amount of filter aid to increase the filtration speed and reduce the problem of new impurities being generated due to prolonged filtration time.

[0034] 3. The purification method of the present invention is simple and easy to operate, the raw materials are readily available and pollution-free, and the purification effect is excellent and highly practical. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 The structural formula is ethylhexyltriazineone.

[0037] Figure 2 This is the 1H NMR spectrum of impurity H1 detected in this invention.

[0038] Figure 3 This is the mass spectrum of impurity H1 detected in this invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] Example 1

[0041] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating to reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.4) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize, with a crystallization temperature of 3°C.

[0042] Example 2

[0043] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 95%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.2) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 13°C / h to crystallize at a crystallization temperature of 3°C.

[0044] Example 3

[0045] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 96%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.5) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 14°C / h to crystallize at a crystallization temperature of 2°C.

[0046] Example 4

[0047] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 97%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.6) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 13°C / h to crystallize, with a crystallization temperature of 0°C.

[0048] Example 5

[0049] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 99%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating to reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.7) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 10°C / h to crystallize at a crystallization temperature of 2°C.

[0050] Example 6

[0051] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating to reflux to dissolve, then cooling to 55°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.5) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 10°C / h to crystallize at a crystallization temperature of 2°C.

[0052] Example 7

[0053] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating to reflux to dissolve, then cooling to 58°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.9) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 11°C / h to crystallize at a crystallization temperature of 4°C.

[0054] Example 8

[0055] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating to reflux to dissolve, then cooling to 68°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.3) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 10°C / h to crystallize at a crystallization temperature of 4°C.

[0056] Example 9

[0057] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 70°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 9.0) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 15°C / h to crystallize at a crystallization temperature of 2°C.

[0058] Example 10

[0059] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 3 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.0) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 13°C / h to crystallize at a crystallization temperature of 2°C.

[0060] Example 11

[0061] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being twice the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.3) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 11°C / h to crystallize at a crystallization temperature of 5°C.

[0062] Example 12

[0063] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 4 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 65°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.6) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 11°C / h to crystallize at a crystallization temperature of 5°C.

[0064] Example 13

[0065] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.3) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 1.5 h, then filtering while hot, and then cooling at a cooling rate of 11°C / h to crystallize at a crystallization temperature of 3°C.

[0066] Example 14

[0067] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.8) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 11°C / h to crystallize at a crystallization temperature of 3°C.

[0068] Example 15

[0069] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.2) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 1 hour, then filtering while hot, and then cooling at a cooling rate of 11°C / h to crystallize at a crystallization temperature of 3°C.

[0070] Example 16

[0071] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating to reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.5) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 4 hours, then filtering while hot, and then cooling at a cooling rate of 11°C / h to crystallize, with a crystallization temperature of 3°C.

[0072] Example 17

[0073] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being twice the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.20% of ethylhexyltriazine ketone, system pH value is 10.0) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 2°C.

[0074] Example 18

[0075] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.10% of ethylhexyltriazine ketone, system pH value is 8.0) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize, with a crystallization temperature of 2°C.

[0076] Example 19

[0077] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 4 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.30% of ethylhexyltriazine ketone, system pH value is 10.0) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 2°C.

[0078] Example 20

[0079] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.3) and diatomaceous earth 1.3 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 2°C.

[0080] Example 21

[0081] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.4) and diatomaceous earth 1.2 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 3°C.

[0082] Example 22

[0083] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.6) and diatomaceous earth 1.6 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 3°C.

[0084] Example 23

[0085] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.6) and diatomaceous earth 2.0 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 3°C.

[0086] Example 24

[0087] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium acetate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.2) and diatomaceous earth 1.3 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 2°C.

[0088] Example 25

[0089] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding triethylamine (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.0) and diatomaceous earth with a mass of 1.5 times the sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 2°C.

[0090] Example 26

[0091] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of isopropanol and water (isopropanol volume content is 98%), the amount of isopropanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.2) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 2°C.

[0092] Example 27

[0093] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.15% of ethylhexyltriazine ketone, system pH value is 8.3) and magnesium oxide 1.5 times the mass of sodium carbonate, stirring for 2.5 h, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 2°C.

[0094] Comparative Example 1

[0095] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve it, then cooling to 62°C, adding diatomaceous earth in the same amount as in Example 1, stirring for 2 hours, filtering while hot, and then cooling at a rate of 12°C / h to crystallize at a crystallization temperature of 2°C.

[0096] Comparative Example 2

[0097] A method for preparing an ethylhexyltriazine ketone product includes the following steps: adding crude ethylhexyltriazine ketone to a mixed solvent of ethanol and water (ethanol volume content is 98%), the amount of ethanol being 2.5 times the mass of the crude ethylhexyltriazine ketone, heating under reflux to dissolve, then cooling to 62°C, adding sodium carbonate (mass addition amount is 0.40% of ethylhexyltriazine ketone, system pH value is 10.6) and diatomaceous earth 1.5 times the mass of sodium carbonate, stirring for 2 hours, then filtering while hot, and then cooling at a cooling rate of 12°C / h to crystallize at a crystallization temperature of 2°C.

[0098] Comparative Example 3

[0099] After dissolving the crude ethylhexyltriazine in 3% acetic acid and refluxing, the pH of the solution was controlled at 5, and the temperature was lowered to 5°C for crystallization. The resulting purified ethylhexyltriazine product can remove impurity H, reducing the content of impurity H to below 0.03%. However, the content of impurity B will increase, making it difficult to dissolve in OS, and the product yield will decrease significantly.

[0100] like Figure 2 and 3 The image shows the 1H NMR spectrum and mass spectrum of impurity H1 separated in this invention. The two impurities are interconvertible. Since impurity H2 is unstable and generally cannot exist stably, impurity H mainly exists in the form of H1.

[0101] Table 1. Purification effects of Examples 1-27 and Comparative Examples 1-3

[0102]

[0103]

[0104] As shown in Table 1, within the parameter range defined by this invention, impurities H (including H1 and H2) and B can be effectively removed, reaching the specified range. When no weak alkali is added, the content of impurities H and B increases significantly, and the yield decreases. When the weak alkali content is too high, impurity H can be effectively removed, but the content of impurity B increases, and the product yield also decreases. When no filter aid is added, impurities H and B can be effectively removed, only the yield decreases, indicating that the filter aid can prevent pore clogging, thereby ensuring yield and filtration efficiency. Excessive stirring time leads to an increase in the content of impurity B. Therefore, this invention, through improvements to the purification process, can shorten the purification time while ensuring efficient removal of impurities H and B.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for the preparation of an ethylhexyl triazone product, characterized in that, The application relates to a method for preparing ethylhexyl triazone. The ethylhexyl triazone crude product is dissolved in an alcohol solvent and refluxed, mixed with an alkaline solution and a filter aid at 55-70 DEG C, filtered while hot, and then crystallized under alkaline conditions with a pH value of 8-10; The alkaline solution is an organic alkali solution or an inorganic alkali solution. The pH value is 8-9.

2. The process for the preparation of ethylhexyl triazone product according to claim 1, characterized in that, The inorganic alkali in the inorganic alkali solution is used in an amount of 0.1%-0.4% of the mass of the ethylhexyl triazone crude product.

3. The process for the preparation of ethylhexyl triazone product according to claim 2, characterized in that, The organic alkali in the organic alkali solution is selected from one or more of triethylamine, diethylamine, triethanolamine, acetate and formate, and the inorganic alkali in the inorganic alkali solution is selected from one or more of carbonate, bicarbonate and ammonia water.

4. The method of preparing an ethylhexyl triazone product according to claim 1, characterized in that, The inorganic alkali in the inorganic alkali solution is used in an amount of 0.1%-0.2% of the mass of the ethylhexyl triazone crude product.

5. The method of preparing an ethylhexyl triazone product according to claim 3, characterized in that, The inorganic alkali in the inorganic alkali solution is used in an amount of 0.15% of the mass of the ethylhexyl triazone crude product.

6. The method of preparing an ethylhexyl triazone product according to claim 5, characterized in that, The ethylhexyl triazone crude product is mixed with an alkaline solution at 58-68 DEG C, filtered while hot, and then crystallized under alkaline conditions with a pH value of 8-10.

7. The method of preparing an ethylhexyl triazone product according to claim 1, characterized in that, The ethylhexyl triazone crude product is mixed with an alkaline solution at 62 DEG C, filtered while hot, and then crystallized under alkaline conditions with a pH value of 8-10.

8. The process for the preparation of ethylhexyl triazone product according to claim 7, characterized in that, The filter aid is used in an amount of 1.2-2.0 times the mass of the organic alkali and / or inorganic alkali.

9. The method of preparing an ethylhexyl triazone product according to claim 1, characterized in that, The filter aid is used in an amount of 1.3-1.6 times the mass of the organic alkali and / or inorganic alkali.

10. The method of preparing an ethylhexyl triazone product according to claim 9, characterized in that, The filter aid is one or more of diatomite, perlite, cellulose, asbestos, graphite powder, sawdust, magnesium oxide, gypsum, activated carbon and acid clay.

11. The method of preparing an ethylhexyl triazone product according to claim 1, characterized in that, The filter aid is diatomite.

12. The method of preparing an ethylhexyl triazone product according to claim 11, characterized in that, The ethylhexyl triazone crude product is dissolved in an alcohol solvent and refluxed, then cooled to 55-70 DEG C, and then an organic alkali and / or inorganic alkali and a filter aid are added, the pH value is controlled to be less than or equal to 10, stirring is performed until the stirring is sufficient, then the mixture is filtered while hot, and then the mixture is cooled and crystallized to obtain the ethylhexyl triazone product.

13. The method of preparing an ethylhexyl triazone product according to claim 1, wherein, The alcohol solvent is one or more of ethanol, isopropyl alcohol and butanol. The alcohol solvent is added in an amount of 2-4 times the mass of the ethylhexyl triazone crude product.

14. The method of preparing an ethylhexyl triazone product according to claim 13, characterized in that, The alcohol solvent is added in an amount of 2-3 times the mass of the ethylhexyl triazone crude product.

15. The method of preparing an ethylhexyl triazone product according to claim 14, characterized in that, The alcohol solvent is added in an amount of 2.5 times the mass of the ethylhexyl triazone crude product.

16. The method of preparing an ethylhexyl triazone product according to claim 15, wherein, The stirring time is 1-4 h.

17. The process for the preparation of ethylhexyl triazone product as claimed in claim 13, wherein, The stirring time is 1.5-2.5 h.

18. The method of preparing an ethylhexyl triazone product according to claim 17, characterized in that, The stirring time is 2 h.

19. The method of preparing an ethylhexyl triazone product according to claim 18, characterized in that, The cooling speed of the cooling and crystallizing is 10-15 DEG C / h, and the crystallization temperature is 0-5 DEG C.

20. The method of making ethylhexyl triazone product of claim 13, wherein, The content of impurity H in the ethylhexyl triazone product prepared by the method is less than 0.03 wt%, the impurity H is impurities H1 and / or H2 shown in the following structure:

21. The method of making ethylhexyl triazone product according to any one of claims 1-20, wherein, (H1) (H2); and the content of impurity B in the ethylhexyl triazone product is less than 0.05 wt%, and the structure of the impurity B is shown in the following structure: ； ​ ​ ； （B）。

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