A method for purifying chlorophenylglycerin ether

Abstract

This application relates to the field of chemical synthesis and production technology, and specifically discloses a method for refining chlorophenylglycerol ether, including the following steps: (1) Take crude chlorophenylglycerol ether product, mix it with 1.5-2.5 times its own amount of pure water, heat and stir evenly, and adjust the pH value to 7-9 to obtain a premix; (2) Add 2-8% of the mass of crude chlorophenylglycerol ether product as an oxidant to the premix, heat to 50-80℃ and react for 60-90 min, then add 0.5-1.5% of the mass of crude chlorophenylglycerol ether product as a modified adsorbent, keep warm for 40-60 min, and after filtration, obtain the treated product; (3) After water cooling, vacuum concentration and drying of the treated product, obtain refined chlorophenylglycerol ether; the modified adsorbent is prepared from dicyandiamide, formaldehyde and ammonium chloride as raw materials. The method for refining chlorophenylglycerol ether in this application is safer, more efficient and convenient than the traditional multi-solvent purification method, and the refining effect is more excellent and stable, with stronger overall applicability.

Description

Technical Field

[0001] This application relates to the field of chemical synthesis and production technology, and more specifically, it relates to a method for purifying chlorophenylglycerol ether. Background Technology

[0002] Chlorophenylglycerol is a preservative that can be used as a cosmetic bactericide and an antifungal drug. Currently, chlorophenylglycerol is prepared in two ways: one method uses p-chlorophenol and epichlorohydrin as raw materials, reacting them and then recrystallizing with ethanol-water as the recrystallization solvent; the other method uses p-chlorophenol and epichlorohydrin as raw materials, with pyridine or quaternary ammonium salts as catalysts, reacting them and then recrystallizing with a mixed solvent of diethyl ether and petroleum ether or with chloroform.

[0003] In the preparation of chlorophenylglycerol ether, the high reactivity of phenolic raw materials makes them prone to oxidation. Furthermore, during etherification, an E2 elimination reaction occurs simultaneously with the SN2 bimolecular substitution reaction, leading to the formation of colored impurities and byproducts. This limits the application of chlorophenylglycerol ether. Currently, methods to reduce byproduct formation include adjusting and controlling reaction conditions, using various solvents for purification (such as methanol, ethanol, and chloroform), or adding adsorbents for physical adsorption (such as resins, activated carbon, and diatomaceous earth). A combination of these methods aims to remove colored substances from the product.

[0004] Regarding the aforementioned technologies, the inventors believe that when using multiple solvents to purify chlorophenylglycerol ether, certain safety hazards exist due to the volatile, toxic, flammable, and explosive nature of these solvents. Furthermore, the extensive use of multiple solvents not only leads to longer processing times but also increases product costs. Therefore, there is an urgent need to propose a solution to address these technical problems. Summary of the Invention

[0005] In order to efficiently remove the colored substances generated during the preparation of chlorophenylglycerin ether, this application provides a method for purifying chlorophenylglycerin ether.

[0006] This application provides a method for purifying chlorophenylglycerin ether, which adopts the following technical solution:

[0007] A method for purifying chlorophenylglycerin ether includes the following steps:

[0008] (1) Take crude chlorophenylglycerol ether product, mix it with 1.5-2.5 times its own amount of pure water, heat and stir evenly, and adjust the pH value to 7-9 to obtain a premix;

[0009] (2) Add 2-8% of the crude chlorophenyl glycerol ether product mass of the premix in step (1) to the oxidant, heat to 50-80℃ and react for 60-90 min, then add 0.5-1.5% of the crude chlorophenyl glycerol ether product mass of the modified adsorbent, keep warm for 40-60 min, and after filtration, obtain the treated product.

[0010] (3) The processed product obtained in step (2) is cooled with water, concentrated under reduced pressure and dried to obtain purified chlorophenylglycerol ether; the modified adsorbent is prepared by the following steps:

[0011] S1. Dissolve dicyandiamide in distilled water until saturated. Heat to 75-85℃, adjust pH to 7-9, add formaldehyde solution, keep warm for 1.5-2.5h, then adjust pH to 5-6, cool to 65-70℃, add ammonium chloride and keep warm for 1.5-2.5h to obtain intermediate product.

[0012] S2. Mix the intermediate product obtained in step S1 with methanol at a weight ratio of 1:(2-3.5), adjust the pH value to 1.6-2.5, react at 45-55℃ for 2-4 hours, cool and then distill under reduced pressure to obtain the modified adsorbent.

[0013] In step S1, the molar ratio of dicyandiamide, formaldehyde and ammonium chloride is (0.9-1.3):(2.6-3.6):1.

[0014] By adopting the above technical solution, dicyandiamide and formaldehyde are first subjected to a hydroxymethylation reaction to obtain a polymer, which is then modified with ammonium chloride, and finally treated with methanol as an etherifying agent to obtain a modified adsorbent. In the purification process of crude chlorophenylglycerol ether, the use of an oxidant allows for the complete oxidation of colored impurities and incompletely oxidized substances in byproducts. The colored substances treated with the oxidant, under the action of the modified adsorbent, can quickly aggregate into aggregates of a certain particle size, which are effectively removed in subsequent filtration operations. Therefore, the combination of the oxidant and the modified adsorbent enables rapid purification of crude chlorophenylglycerol ether, resulting in high-quality, pure purified chlorophenylglycerol ether. Compared with traditional multi-solvent purification, the overall operation is safer, more efficient, and more convenient. Furthermore, by adjusting the molar ratio of dicyandiamide, formaldehyde, and ammonium chloride, this application makes the obtained modified adsorbent more suitable for aggregating colored substances produced after oxidant treatment, resulting in a stable synergistic effect and a significant purification effect.

[0015] Preferably, the molar ratio of dicyandiamide, formaldehyde and ammonium chloride is 1:3.2:1.

[0016] By adopting the above technical solution, the modified adsorbent prepared from the raw materials in the above molar ratio can not only completely aggregate the colored substances produced after oxidation treatment during the application process, but also make the aggregates have a larger particle size, thus making them easier to filter and remove, thereby obtaining refined chlorophenylglycerol ether of better quality.

[0017] Preferably, step (2) also uses an auxiliary agent of 0.3-0.9% of the crude chlorophenyl glycerol ether product mass. The auxiliary agent is used together with the modified adsorbent after being mixed. The auxiliary agent is composed of activated carbon and attapulgite in a weight ratio of 1:(4-6).

[0018] By employing the above technical solution, activated carbon and attapulgite are used as auxiliary agents, which can achieve excellent synergistic effects with the modified adsorbent. By adsorbing and filling the aggregates formed between the adsorbent and colored substances into its own pore structure, it is not only easier to filter and separate, reducing the number of filtration cycles, but also able to remove small aggregates that are difficult to filter and separate, thus further improving the purification effect. At the same time, although activated carbon and attapulgite have different porous structures and adsorption properties, they can form a good complementary advantage, making them more suitable for fully binding with aggregates. Therefore, it can be seen that by using auxiliary agents composed of activated carbon and attapulgite, the removal effect of colored substances can be significantly improved in the purification process of chlorophenyl glycerol ether, resulting in purified chlorophenyl glycerol ether of superior quality.

[0019] Preferably, the auxiliary agent is composed of activated carbon and attapulgite in a weight ratio of 1:5.

[0020] By adopting the above technical solution, the combination of activated carbon and attapulgite in the above weight ratio has a better effect, and the combination with the modified adsorbent has a better effect on the removal of colored substances, resulting in better quality of refined chlorophenylglycerol ether.

[0021] Preferably, the auxiliary agent is pretreated before use, specifically including the following steps:

[0022] The auxiliary agent is placed in deionized water, activated by adding concentrated nitric acid solution, and then 0.8-1.6% (by weight of the auxiliary agent) of carboxymethyl chitosan is added. The pH is adjusted to 4-6, and the reaction is carried out at 60-70℃ for 60-90 minutes. After filtration, washing and drying, the pretreated auxiliary agent can be obtained.

[0023] By adopting the above technical solution, the dispersibility and adsorption properties of the auxiliary agent after the above treatment are greatly improved, and the binding speed between it and the aggregates is also significantly increased. Adsorption of the aggregates can be completed in a shorter time, thus further improving the purification efficiency and making the purification method for chlorophenyl glycerol ether of this application more efficient and more applicable.

[0024] Preferably, in step (2), after adding the auxiliary agent and the modified adsorbent, the temperature is adjusted to 65-75℃ and kept warm for 15-25 minutes.

[0025] By adopting the above technical solution, at the above temperature, after the modified adsorbent and the colored substance treated with the oxidant form an aggregate, the auxiliary agent can quickly play a role and form a stable bond between the aggregates. Compared with the natural expansion after the aggregates are formed, the use of the auxiliary agent can significantly reduce the operation time. It is more efficient and can also ensure excellent and stable removal of colored impurities, thus making the purification method of chlorophenyl glycerol ether more applicable.

[0026] Preferably, the oxidant is one or a combination of sodium hypochlorite, calcium hypochlorite, perchloric acid, sodium perborate, and hydrogen peroxide.

[0027] By adopting the above technical solutions, the oxidants of the above types can all bring good oxidation effects to colored impurities and incompletely oxidized substances in by-products, ensuring that the final refined chlorophenylglycerol ether has high quality.

[0028] Preferably, the oxidant is composed of sodium perborate and hydrogen peroxide in a weight ratio of 1:(1.6-2.8).

[0029] By adopting the above technical solution, using sodium perborate and hydrogen peroxide together as oxidants, the effect is quite good. It can help to completely convert colored substances, and then, together with the modified adsorbent, it can play an excellent role in removing colored substances, and can obtain refined chlorophenyl glycerol ether with better overall quality.

[0030] In summary, this application has the following beneficial effects:

[0031] 1. This application utilizes a combination of oxidant and modified adsorbent to partially convert colored impurities and byproducts in crude chlorophenyl glycerol ether products, which are then aggregated and removed by filtration. This achieves rapid purification of crude chlorophenyl glycerol ether products and yields high-quality, pure purified chlorophenyl glycerol ether. Furthermore, compared to traditional multi-solvent purification methods, this application offers a safer, more efficient, and more convenient overall operation with greater applicability.

[0032] 2. This application uses an auxiliary agent composed of activated carbon and attapulgite, taking advantage of the complementary strengths of activated carbon and attapulgite. By adsorbing and filling the aggregates formed between the adsorbent and the colored substance into its own pore structure, it is not only easier to be filtered and separated, reducing the number of filtrations, but also able to remove aggregates with small particle size that are difficult to filter and separate, thereby further improving the purification effect. Detailed Implementation

[0033] The present application will be further described in detail below with reference to the embodiments.

[0034] Unless otherwise specified, all raw materials used in the preparation examples and embodiments of this application are commercially available.

[0035] The activated carbon was purchased from Henan Shuoyuanda Environmental Protection Technology Co., Ltd., and the particle size was 200 mesh.

[0036] Attapulgite clay was purchased from Hongtao Mineral Products Processing Plant in Lingshou County, with a particle size of 325mm.

[0037] Carboxymethyl chitosan CAS No. 83512-85-0.

[0038] Preparation of raw materials and / or intermediates Example 1

[0039] A modified adsorbent is prepared by the following steps:

[0040] S1. Dissolve dicyandiamide in distilled water until saturated. Heat to 80°C, adjust pH to 8, add formaldehyde solution, keep warm for 2 hours, then adjust pH to 5.5, cool to 67.5°C, add ammonium chloride and keep warm for 2 hours to obtain intermediate product.

[0041] S2. Mix the intermediate product obtained in step S1 with methanol at a weight ratio of 1:2.75, adjust the pH value to 2, react at 50°C for 3 hours, cool and then distill under reduced pressure to obtain the modified adsorbent.

[0042] In step S1, the molar ratio of dicyandiamide, formaldehyde, and ammonium chloride is 1:3.2:1.

[0043] Preparation Example 2

[0044] A modified adsorbent is prepared by the following steps:

[0045] S1. Dissolve dicyandiamide in distilled water until saturated. Heat to 85°C, adjust pH to 9, add formaldehyde solution, keep warm for 1.5 hours, then adjust pH to 5, cool to 70°C, add ammonium chloride and keep warm for 1.5 hours to obtain intermediate product.

[0046] S2. Mix the intermediate product obtained in step S1 with methanol at a weight ratio of 1:3.5, adjust the pH value to 2.5, react at 55℃ for 2 hours, cool and then distill under reduced pressure to obtain the modified adsorbent.

[0047] Preparation Example 3

[0048] A modified adsorbent is prepared by the following steps:

[0049] S1. Dicyandiamide was saturated and dissolved in distilled water. The solution was heated to 75°C, and the pH was adjusted to 7. Formaldehyde solution was added, and the reaction was kept at this temperature for 2.5 hours. The pH was then adjusted to 6, and the temperature was lowered to 65°C. Ammonium chloride was added and the reaction was kept at this temperature for 2.5 hours to obtain the intermediate product.

[0050] S2. Mix the intermediate product obtained in step S1 with methanol at a weight ratio of 1:2, adjust the pH value to 1.6, react at 45℃ for 4 hours, cool and then distill under reduced pressure to obtain the modified adsorbent.

[0051] Preparation Example 4

[0052] A modified adsorbent, which differs from Preparation Example 1 in that, in step S1, the molar ratio of dicyandiamide, formaldehyde and ammonium chloride is 1.1:3.1:1.

[0053] Preparation Example 5

[0054] A modified adsorbent, which differs from Preparation Example 1 in that, in step S1, the molar ratio of dicyandiamide, formaldehyde, and ammonium chloride is 0.9:2.6:1.

[0055] Preparation Example 6

[0056] A modified adsorbent, which differs from Preparation Example 1 in that, in step S1, the molar ratio of dicyandiamide, formaldehyde and ammonium chloride is 1.3:3.6:1.

[0057] Preparation Example 7

[0058] A modified adsorbent, which differs from Preparation Example 1 in that, in step S1, the molar ratio of dicyandiamide, formaldehyde and ammonium chloride is 0.8:2.5:1.

[0059] Preparation Example 8

[0060] A modified adsorbent, which differs from Preparation Example 1 in that, in step S1, the molar ratio of dicyandiamide, formaldehyde and ammonium chloride is 1.4:3.7:1.

[0061] Preparation Example 9

[0062] A modified adsorbent, which differs from Preparation Example 1 in that, in step S1, the molar ratio of dicyandiamide, formaldehyde and ammonium chloride is 0.8:3.2:1.

[0063] Preparation Example 10

[0064] A modified adsorbent, which differs from Preparation Example 1 in that, in step S1, the molar ratio of dicyandiamide, formaldehyde and ammonium chloride is 1.4:3.2:1.

[0065] Preparation Example 11

[0066] A modified adsorbent, which differs from Preparation Example 1 in that, in step S1, the molar ratio of dicyandiamide, formaldehyde and ammonium chloride is 1:2.5:1.

[0067] Preparation Example 12

[0068] A modified adsorbent, which differs from Preparation Example 1 in that, in step S1, the molar ratio of dicyandiamide, formaldehyde and ammonium chloride is 1:3.7:1.

[0069] Example

[0070] Example 1

[0071] A method for purifying chlorophenylglycerin ether includes the following steps:

[0072] (1) Take crude chlorophenylglycerol ether product, mix it with twice its own amount of pure water, heat it to 80℃ and stir it evenly, and adjust the pH value to 8 to obtain a premix;

[0073] (2) Add 5% of the crude chlorophenyl glycerol ether product mass of oxidant to the premix in step (1), heat to 65℃ and react for 75 min, then add 1% of the crude chlorophenyl glycerol ether product mass of modified adsorbent, keep warm for 50 min, and after filtration, obtain the treated product.

[0074] (3) The processed product obtained in step (2) is cooled by water, concentrated and dried under reduced pressure to obtain refined chlorophenylglycerol ether.

[0075] Note: The modified adsorbent used in the above steps was obtained in Preparation Example 1; the oxidant was composed of sodium perborate and hydrogen peroxide in a weight ratio of 1:2.2.

[0076] Example 2

[0077] A method for purifying chlorophenylglycerin ether, which differs from Example 1 in that it includes the following steps:

[0078] (1) Take crude chlorophenylglycerol ether product, mix it with 1.5 times its own amount of pure water, heat it to 80℃ and stir it evenly, and adjust the pH value to 7 to obtain a premix;

[0079] (2) Add 2% of the crude chlorophenyl glycerol ether product mass of oxidant to the premix in step (1), heat to 50℃ and react for 90 min, then add 1.5% of the crude chlorophenyl glycerol ether product mass of modified adsorbent, keep warm for 40 min, and after filtration, obtain the treated product.

[0080] (3) The processed product obtained in step (2) is cooled by water, concentrated and dried under reduced pressure to obtain refined chlorophenylglycerol ether.

[0081] Example 3

[0082] A method for purifying chlorophenylglycerin ether, which differs from Example 1 in that it includes the following steps:

[0083] (1) Take crude chlorophenylglycerol ether product, mix it with 2.5 times its own volume of pure water, heat it to 80℃ and stir it evenly, and adjust the pH value to 9 to obtain a premix;

[0084] (2) Add 8% of the crude chlorophenyl glycerol ether product mass of oxidant to the premix in step (1), heat to 80℃ and react for 60 min, then add 0.5% of the crude chlorophenyl glycerol ether product mass of modified adsorbent, keep warm for 60 min, and after filtration, obtain the treated product.

[0085] (3) The processed product obtained in step (2) is cooled by water, concentrated and dried under reduced pressure to obtain refined chlorophenylglycerol ether.

[0086] Example 4

[0087] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 2.

[0088] Example 5

[0089] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 3.

[0090] Example 6

[0091] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 4.

[0092] Example 7

[0093] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 5.

[0094] Example 8

[0095] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 6.

[0096] Example 9

[0097] A method for purifying chlorophenylglycerol ether, which differs from Example 1, is provided in that the oxidant is composed of sodium perborate and hydrogen peroxide in a weight ratio of 1:1.6.

[0098] Example 10

[0099] A method for purifying chlorophenylglycerol ether, which differs from Example 1, is provided in that the oxidant is composed of sodium perborate and hydrogen peroxide in a weight ratio of 1:2.8.

[0100] Example 11

[0101] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the oxidant is sodium perborate.

[0102] Example 12

[0103] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the oxidant is hydrogen peroxide.

[0104] Example 13

[0105] A method for refining chlorophenylglycerin ether differs from Example 1 in that step (2) also uses 0.6% of the crude chlorophenylglycerin ether product mass as an auxiliary agent. The auxiliary agent is mixed with the modified adsorbent and used together. After adding the auxiliary agent and the modified adsorbent, the temperature is adjusted to 70°C and kept warm for 20 minutes. The auxiliary agent is composed of activated carbon and attapulgite in a weight ratio of 1:5.

[0106] Example 14

[0107] A method for refining chlorophenylglycerin ether, which differs from Example 13, is that step (2) also uses an auxiliary agent of 0.3% by weight of the crude chlorophenylglycerin ether product.

[0108] Example 15

[0109] A method for refining chlorophenylglycerin ether, which differs from Example 13, is that step (2) also uses an auxiliary agent of 0.9% by weight of the crude chlorophenylglycerin ether product.

[0110] Example 16

[0111] A method for refining chlorophenylglycerin ether, which differs from Example 13, is provided in that the auxiliary agent is composed of activated carbon and attapulgite in a weight ratio of 1:4.

[0112] Example 17

[0113] A method for refining chlorophenylglycerin ether, which differs from Example 13, is provided in that the auxiliary agent is composed of activated carbon and attapulgite in a weight ratio of 1:6.

[0114] Example 18

[0115] A method for refining chlorophenylglycerin ether, which differs from Example 13, is provided in that the auxiliary agent is composed of activated carbon and attapulgite in a weight ratio of 1:3.8.

[0116] Example 19

[0117] A method for refining chlorophenylglycerin ether, which differs from Example 13, is provided in that the auxiliary agent is composed of activated carbon and attapulgite in a weight ratio of 1:6.2.

[0118] Example 20

[0119] A method for purifying chlorophenylglycerol ether, which differs from Example 13 in that the auxiliary agent does not contain activated carbon.

[0120] Example 21

[0121] A method for refining chlorophenylglycerin ether, which differs from Example 13 in that the auxiliary agents do not contain attapulgite.

[0122] Example 22

[0123] A method for purifying chlorophenylglycerol ether, which differs from Example 13, involves adjusting the temperature to 65°C and holding it at that temperature for 25 minutes after adding auxiliary agents and modified adsorbents.

[0124] Example 23

[0125] A method for purifying chlorophenylglycerol ether, which differs from Example 13, involves adjusting the temperature to 75°C and holding it at that temperature for 15 minutes after adding the auxiliary agent and the modified adsorbent.

[0126] Example 24

[0127] A method for purifying chlorophenylglycerin ether, which differs from Example 13, involves pretreatment of the auxiliary agents before use, specifically including the following steps:

[0128] The auxiliary agent is placed in deionized water, activated by adding concentrated nitric acid solution, and then 1.2% by weight of carboxymethyl chitosan is added. The pH value is adjusted to 5, and the reaction is carried out at 65℃ for 75 minutes. After filtration, washing and drying, the pretreated auxiliary agent can be obtained.

[0129] In step (2), after adding the pretreatment auxiliary agent and the modified adsorbent, adjust the temperature to 70℃ and keep it warm for 10 minutes.

[0130] Example 25

[0131] A method for purifying chlorophenylglycerin ether, which differs from Example 13, involves pretreatment of the auxiliary agents before use, specifically including the following steps:

[0132] The auxiliary agent is placed in deionized water, activated by adding concentrated nitric acid solution, and then 0.8% (by weight) of carboxymethyl chitosan is added. The pH is adjusted to 6, and the reaction is carried out at 60°C for 90 minutes. After filtration, washing and drying, the pretreated auxiliary agent is obtained.

[0133] Example 26

[0134] A method for purifying chlorophenylglycerin ether, which differs from Example 13, involves pretreatment of the auxiliary agents before use, specifically including the following steps:

[0135] The auxiliary agent is placed in deionized water, activated by adding concentrated nitric acid solution, and then 1.6% (by weight) of carboxymethyl chitosan is added. The pH is adjusted to 4, and the reaction is carried out at 70°C for 60 minutes. After filtration, washing and drying, the pretreated auxiliary agent is obtained.

[0136] Comparative Example

[0137] Comparative Example 1

[0138] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 7.

[0139] Comparative Example 2

[0140] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 8.

[0141] Comparative Example 3

[0142] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 9.

[0143] Comparative Example 4

[0144] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 10.

[0145] Comparative Example 5

[0146] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 11.

[0147] Comparative Example 6

[0148] A method for purifying chlorophenylglycerol ether, which differs from Example 1 in that the modified adsorbent is obtained in Preparation Example 12.

[0149] Comparative Example 7

[0150] A method for purifying chlorophenylglycerin ether, which differs from Example 1 in that no oxidant is used in step (2).

[0151] Comparative Example 8

[0152] A method for purifying chlorophenylglycerol ether, which differs from Example 13 in that a modified adsorbent is not used in step (2).

[0153] Performance testing sample: Crude chlorophenylglycerol ether product, prepared by the following method: 1g of 3-chloro-1,2-propanediol and 1g of p-chlorophenol were added to 10g of potassium hydroxide solution, followed by 0.02g of alkylammonium bromide catalyst and stirred evenly to obtain a reaction solution. The reaction solution was then heated to 50℃ and reacted for 2h. After cooling and adjusting the pH of the reaction solution to 7, it was allowed to stand for 1h. The lower organic phase was taken out and placed in stirred chloroform to crystallize. After freezing for 4h, it was filtered and dried under vacuum at 55℃ to obtain the crude chlorophenylglycerol ether product.

[0154] Experimental Methods: The purification methods for chlorophenylglycerin ethers in Examples 1-26 and Comparative Examples 1-8 were used to purify the above-mentioned test samples (crude chlorophenylglycerin ether products), yielding 34 refined chlorophenylglycerin ethers. A light source and a light intensity measuring instrument were prepared. First, the light intensity emitted by the light source was measured. Then, the refined chlorophenylglycerin ethers were placed in the light source and light intensity measuring instrument for quality inspection. The light source was turned on, allowing light to pass through the refined chlorophenylglycerin ethers, and the intensity of the transmitted light was measured. Finally, the transparency percentage, i.e., the ratio of the transmitted light source intensity to the light source intensity, was calculated. The higher the transparency percentage value, the purer the crude chlorophenylglycerin ether product. The above tests were performed on the 34 refined chlorophenylglycerin ethers in sequence, and the obtained transparency percentages corresponding to Examples 1-26 and Comparative Examples 1-8 were recorded in Table 1.

[0155] Table 1. Application test results of Examples 1-26 and Comparative Examples 1-8

[0156]

[0157] Based on Examples 1-3, Comparative Examples 1-7, and the control example (crude chlorophenylglycerol ether product), and referring to Table 1, it can be seen that the combined use of an oxidant and a modified adsorbent yields a higher quality refined chlorophenylglycerol ether, and the percentage of transparency obtained in the refined chlorophenylglycerol ether test is also relatively high. However, without the oxidant, although the modified adsorbent can remove some colored substances, its effect is far less than that achieved by the combination of the two. Furthermore, based on Examples 4-8 and Table 1, it can be seen that when the molar ratio of dicyandiamide, formaldehyde, and ammonium chloride is (0.9-1.3):(2.6-3.6):1, the resulting modified adsorbent is more suitable for aggregating the colored substances produced after oxidant treatment, resulting in a relatively high and stable percentage of transparency for the refined chlorophenylglycerol ether. When any one or two of the three raw materials exceed the above dosage range, there is no significant loss in the effect of the modified adsorbent, resulting in a decrease in the percentage of transparency of the refined chlorophenylglycerol ether.

[0158] As can be seen from Examples 9-10 and 11-12 and Table 1, the oxidant composed of sodium perborate and hydrogen peroxide in a specific weight ratio range exhibits excellent and stable effects. However, the effect of using either sodium perborate or hydrogen peroxide alone as an oxidant is far less than that of using them together, thus resulting in a refined chlorophenylglycerol ether of superior quality.

[0159] As can be seen from Examples 1 and 13-15, and in conjunction with Table 1, the auxiliary agent composed of activated carbon and attapulgite can further improve the quality of refined chlorophenylglycerin ether, and the measured percentage of transparency is also significantly increased. Furthermore, as can be seen from Examples 16-19, and in conjunction with Table 1, when activated carbon and attapulgite are used as auxiliary agents in a weight ratio of 1:(4-6), they all exhibit stable and excellent effects. However, exceeding this range leads to a loss of the effects brought about by the application of the auxiliary agent. Furthermore, as can be seen from Examples 20-21, and in conjunction with Table 1, using either activated carbon or attapulgite alone as an auxiliary agent yields limited effects, far less than the superior effects of their combination. Therefore, activated carbon and attapulgite can exert excellent synergistic effects in the technical solution of this application. Combined with Examples 22-23 and Table 1, it can be seen that the use of auxiliary agents can significantly reduce the operation time, and while being more efficient, it can also ensure excellent and stable removal of colored impurities, thus making the purification method of chlorophenylglycerin ether more applicable.

[0160] As can be seen from Examples 13 and 24-16 and Table 1, pretreatment of the auxiliary agent before use with the modified adsorbent can further improve the purification effect of chlorophenylglycerin ether, resulting in a higher quality purified chlorophenylglycerin ether.

[0161] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for purifying chlorophenylglycerin, characterized in that, Includes the following steps: (1) Take crude chlorophenylglycerol ether product, mix it with 1.5-2.5 times its own amount of pure water, heat and stir evenly, and adjust the pH value to 7-9 to obtain a premix; (2) Add 2-8% of the crude chlorophenyl glycerol ether product mass of the premix in step (1) to the oxidant, heat to 50-80℃ and react for 60-90 min, then add 0.5-1.5% of the crude chlorophenyl glycerol ether product mass of the modified adsorbent, keep warm for 40-60 min, and after filtration, obtain the treated product; (3) The processed product obtained in step (2) is cooled by water, concentrated and dried under reduced pressure to obtain refined chlorophenylglycerol ether; The modified adsorbent is prepared by the following steps: S1. Dissolve dicyandiamide in distilled water until saturated. Heat to 75-85℃, adjust pH to 7-9, add formaldehyde solution, keep warm for 1.5-2.5h, then adjust pH to 5-6, cool to 65-70℃, add ammonium chloride and keep warm for 1.5-2.5h to obtain intermediate product. S2. Mix the intermediate product obtained in step S1 with methanol at a weight ratio of 1:(2-3.5), adjust the pH value to 1.6-2.5, react at 45-55℃ for 2-4 hours, cool and then distill under reduced pressure to obtain the modified adsorbent. In step S1, the molar ratio of dicyandiamide, formaldehyde, and ammonium chloride is (0.9-1.3):(2.6-3.6):1; In step (2), 0.3-0.9% of the crude chlorophenyl glycerol ether product mass of auxiliary agent is also used. The auxiliary agent is mixed with the modified adsorbent and used together. The auxiliary agent is composed of activated carbon and attapulgite in a weight ratio of 1:(4-6). The oxidant is composed of sodium perborate and hydrogen peroxide in a weight ratio of 1:(1.6-2.8).

2. The method for purifying chlorophenylglycerin ether according to claim 1, characterized in that: The molar ratio of dicyandiamide, formaldehyde, and ammonium chloride is 1:3.2:

1.

3. The method for purifying chlorophenylglycerin ether according to claim 1, characterized in that: The auxiliary agent is composed of activated carbon and attapulgite in a weight ratio of 1:

5.

4. The method for purifying chlorophenylglycerin ether according to claim 1, characterized in that: The auxiliary agents are pretreated before use, specifically including the following steps: The auxiliary agent is placed in deionized water, activated by adding concentrated nitric acid solution, and then 0.8-1.6% (by weight of the auxiliary agent) of carboxymethyl chitosan is added. The pH is adjusted to 4-6, and the reaction is carried out at 60-70℃ for 60-90 minutes. After filtration, washing and drying, the pretreated auxiliary agent can be obtained.

5. The method for purifying chlorophenylglycerin ether according to claim 1, characterized in that: In step (2), after adding the auxiliary agent and the modified adsorbent, adjust the temperature to 65-75℃ and keep it warm for 15-25 minutes.

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