CN115504872A - Purification method of p-hydroxyacetophenone - Google Patents
Purification method of p-hydroxyacetophenone Download PDFInfo
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- CN115504872A CN115504872A CN202211137423.9A CN202211137423A CN115504872A CN 115504872 A CN115504872 A CN 115504872A CN 202211137423 A CN202211137423 A CN 202211137423A CN 115504872 A CN115504872 A CN 115504872A
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- TXFPEBPIARQUIG-UHFFFAOYSA-N 4'-hydroxyacetophenone Chemical compound CC(=O)C1=CC=C(O)C=C1 TXFPEBPIARQUIG-UHFFFAOYSA-N 0.000 title claims abstract description 446
- 238000000034 method Methods 0.000 title claims abstract description 90
- 238000000746 purification Methods 0.000 title claims abstract description 55
- 239000000047 product Substances 0.000 claims abstract description 126
- 238000002425 crystallisation Methods 0.000 claims abstract description 81
- 230000008025 crystallization Effects 0.000 claims abstract description 81
- 208000008454 Hyperhidrosis Diseases 0.000 claims abstract description 70
- 230000035900 sweating Effects 0.000 claims abstract description 70
- 238000002844 melting Methods 0.000 claims abstract description 30
- 230000008018 melting Effects 0.000 claims abstract description 30
- 239000007788 liquid Substances 0.000 claims abstract description 28
- 238000010438 heat treatment Methods 0.000 claims abstract description 25
- 239000012043 crude product Substances 0.000 claims abstract description 24
- 230000009467 reduction Effects 0.000 claims abstract description 10
- 239000013078 crystal Substances 0.000 claims description 37
- 239000012452 mother liquor Substances 0.000 claims description 30
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 26
- 238000001816 cooling Methods 0.000 claims description 23
- 239000002994 raw material Substances 0.000 claims description 18
- 229910052757 nitrogen Inorganic materials 0.000 claims description 12
- 230000000630 rising effect Effects 0.000 claims description 11
- 239000003153 chemical reaction reagent Substances 0.000 claims description 8
- 239000011261 inert gas Substances 0.000 claims description 8
- 238000001953 recrystallisation Methods 0.000 claims description 5
- 239000007858 starting material Substances 0.000 claims 1
- 238000012360 testing method Methods 0.000 abstract description 13
- 239000002904 solvent Substances 0.000 abstract description 9
- 239000000126 substance Substances 0.000 abstract description 6
- 238000005265 energy consumption Methods 0.000 abstract description 3
- 238000003912 environmental pollution Methods 0.000 abstract description 2
- 230000000052 comparative effect Effects 0.000 description 25
- 239000012535 impurity Substances 0.000 description 24
- 230000008569 process Effects 0.000 description 18
- 238000001514 detection method Methods 0.000 description 15
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 12
- RFFLAFLAYFXFSW-UHFFFAOYSA-N 1,2-dichlorobenzene Chemical compound ClC1=CC=CC=C1Cl RFFLAFLAYFXFSW-UHFFFAOYSA-N 0.000 description 10
- JECYUBVRTQDVAT-UHFFFAOYSA-N 2-acetylphenol Chemical compound CC(=O)C1=CC=CC=C1O JECYUBVRTQDVAT-UHFFFAOYSA-N 0.000 description 10
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 description 10
- 238000011084 recovery Methods 0.000 description 10
- 210000004243 sweat Anatomy 0.000 description 8
- 239000003755 preservative agent Substances 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
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- 238000004458 analytical method Methods 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000004817 gas chromatography Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
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- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 238000005507 spraying Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
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- MVNVIVWSAFEIII-UHFFFAOYSA-N 1-(4-hydroxyphenyl)ethanone Chemical compound CC(=O)C1=CC=C(O)C=C1.CC(=O)C1=CC=C(O)C=C1 MVNVIVWSAFEIII-UHFFFAOYSA-N 0.000 description 1
- IPBVNPXQWQGGJP-UHFFFAOYSA-N acetic acid phenyl ester Natural products CC(=O)OC1=CC=CC=C1 IPBVNPXQWQGGJP-UHFFFAOYSA-N 0.000 description 1
- -1 alcohol ester Chemical class 0.000 description 1
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000004042 decolorization Methods 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000032050 esterification Effects 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 239000005457 ice water Substances 0.000 description 1
- 230000007794 irritation Effects 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229940049953 phenylacetate Drugs 0.000 description 1
- WLJVXDMOQOGPHL-UHFFFAOYSA-N phenylacetic acid Chemical compound OC(=O)CC1=CC=CC=C1 WLJVXDMOQOGPHL-UHFFFAOYSA-N 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000002335 preservative effect Effects 0.000 description 1
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- 230000001737 promoting effect Effects 0.000 description 1
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- 239000003381 stabilizer Substances 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/78—Separation; Purification; Stabilisation; Use of additives
- C07C45/81—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C49/00—Ketones; Ketenes; Dimeric ketenes; Ketonic chelates
- C07C49/76—Ketones containing a keto group bound to a six-membered aromatic ring
- C07C49/82—Ketones containing a keto group bound to a six-membered aromatic ring containing hydroxy groups
- C07C49/825—Ketones containing a keto group bound to a six-membered aromatic ring containing hydroxy groups all hydroxy groups bound to the ring
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The application relates to the technical field of chemical purification, and particularly discloses a purification method of p-hydroxyacetophenone. The application discloses a purification method of p-hydroxyacetophenone, which specifically comprises the following steps: heating and melting the p-hydroxyacetophenone crude product to obtain a molten liquid; sequentially carrying out cold crystallization and heating sweating treatment on the molten liquid to obtain a p-hydroxyacetophenone product; wherein, in the cold crystallization treatment: the temperature reduction frequency is less than or equal to 1.5 ℃/min, and the final crystallization temperature is 97-103 ℃; in the temperature-rising sweating treatment: the heating frequency is 0.8-1.2 ℃/h, and the final sweating temperature is 107-110 ℃. The purification method has the advantages of convenient operation, no need of solvent, little environmental pollution, low energy consumption and low test cost; meanwhile, the purity and the yield of the p-hydroxyacetophenone can be obviously improved by utilizing the purification method.
Description
Technical Field
The application relates to the technical field of chemical purification, in particular to a purification method of p-hydroxyacetophenone.
Background
The personal care product is a daily chemical industrial product, which is spread on the surface of a human body by smearing, spraying or other similar methods so as to achieve the purposes of cleaning, eliminating bad smell, protecting skin, beautifying and decorating. The variety of raw materials involved in personal care products is wide, and among them, p-hydroxyacetophenone is a material widely used in personal care products.
p-Hydroxyacetophenone (p-Hydroxyacetophenone) is one of the safest high-temperature auxiliary activity stabilizers in the medical field at present, and is a novel personal care product raw material with the function of promoting preservative synergism. Meanwhile, the p-hydroxyacetophenone has excellent compatibility, can be compounded with various raw materials of personal care products, and has almost no irritation to the skin. Current research shows that p-hydroxyacetophenone can be used as a synergist of traditional preservatives, and the p-hydroxyacetophenone is added into a personal care product, so that the using amount of the traditional preservatives (such as aromatic preservatives, hindered phenol preservatives and alcohol ester preservatives) can be effectively reduced, the stimulation of the traditional preservatives to human skin is effectively reduced, and the safety of the personal care product is favorably improved. Therefore, in order to broaden the use of p-hydroxyacetophenone in personal care products, it is necessary to increase the purity of p-hydroxyacetophenone products.
At present, the purification process of p-hydroxyacetophenone mainly comprises the following steps: dissolving the crude p-hydroxyacetophenone product in a mixed solvent of alcohol and water, heating for dissolving, and then carrying out decoloration treatment by using activated carbon; then slowly cooling and crystallizing the decolorized solution, and centrifuging to obtain the p-hydroxyacetophenone product. However, the purification process is complicated to operate, low in single yield, high in energy consumption, and environment-friendly due to the use of a large amount of chemical solvents, and the cost is high. In addition, the p-hydroxyacetophenone product produced by the purification technology has many defects, such as harmful substances including phenol as a production raw material, o-hydroxyacetophenone as a byproduct, hydroquinone, organic solvents and the like, and if the p-hydroxyacetophenone product is used for personal care products, the safety of the product is easily reduced. Meanwhile, the p-hydroxyacetophenone product has a large pungent smell and has a yellow color, so that the attractiveness and the use experience of the personal care product are reduced.
Based on the above, the existing purification process of p-hydroxyacetophenone causes unprecedented difficulty in the expansion and production of the product by various manufacturers, which causes the problem of insufficient supply, and severely limits the application of p-hydroxyacetophenone in personal care products.
Disclosure of Invention
In order to provide a purification method of p-hydroxyacetophenone, which is convenient to operate, low in energy consumption and low in environmental pollution, and can overcome the defects that impurities in a crude p-hydroxyacetophenone product are difficult to remove, the color degree is difficult to control, the purity of the product is low, and the yield is low, the application provides the purification method of p-hydroxyacetophenone.
In a first aspect, the present application provides a method for purifying p-hydroxyacetophenone.
A method for purifying p-hydroxyacetophenone specifically comprises the following steps:
heating and melting the p-hydroxyacetophenone crude product to obtain a molten liquid;
sequentially carrying out cold crystallization and heating sweating treatment on the molten liquid to obtain a p-hydroxyacetophenone product;
wherein, in the cold crystallization treatment: the temperature reduction frequency is less than or equal to 1.5 ℃/min, and the final crystallization temperature is 97-103 ℃;
in the temperature-rising sweating treatment: the temperature rising frequency is 0.8-1.2 ℃/h; the final sweating temperature is 107-110 ℃.
According to the method, the p-hydroxyacetophenone product is obtained by heating and melting the p-hydroxyacetophenone crude product, and performing cold crystallization and heating sweating treatment. By utilizing the purification method, the purity of the p-hydroxyacetophenone product is higher than 99.90%, and the once-through yield is higher than 77%, which shows that the purification method obviously improves the yield and the purity of the p-hydroxyacetophenone product.
The purification method provided by the application utilizes the melt crystallization technology, is simple to operate, can effectively remove impurities, and the obtained p-hydroxyacetophenone product has low chroma and no pungent smell. In addition, the whole process of the purification method does not need to use a solvent, so that the test flow is shortened, secondary pollution caused by other solvents is avoided, the problems of solvent adding cost and solvent recovery are not considered, and the preparation cost of the p-hydroxyacetophenone product is effectively reduced.
Generally, the purity of the crude p-hydroxyacetophenone processed by the purification method of the present application is 90.00-99.90%, and the melting point of the crude p-hydroxyacetophenone is 102.3-106.7 ℃.
The crude p-hydroxyacetophenone product obtained by the existing production process of p-hydroxyacetophenone usually contains impurities of phenol, hydroquinone, o-hydroxyacetophenone and residual organic solvent o-dichlorobenzene, and the substances are difficult to remove, so that the purity of the p-hydroxyacetophenone is low. The purification method provided by the application can effectively remove the impurities and obviously improve the purity of the p-hydroxyacetophenone.
Further, the temperature of the temperature-rising melting is 115 +/-3 ℃.
When the temperature of the p-hydroxyacetophenone crude product is raised to 115 +/-3 ℃, the p-hydroxyacetophenone crude product can be completely melted to present the state of molten liquid, and the subsequent cold crystallization process operation is facilitated.
The cold crystallization process is that the temperature of the melt liquid at 115 +/-3 ℃ is reduced in a molten state, the melt liquid is in a supersaturated state in the cold crystallization process, and the p-hydroxyacetophenone in the melt liquid starts to nucleate and gradually grows into p-hydroxyacetophenone coarse crystals; in the subsequent cooling process, the p-hydroxyacetophenone crude crystal continues to grow, the uncrystallized molten liquid becomes crystallization mother liquid, and impurities in the crystallization mother liquid can be occluded on the surface and in the crude crystal. Therefore, the parameter conditions of the cold crystallization need to be reasonably controlled, and the impurities occluded in the p-hydroxyacetophenone crude crystal are reduced, so that the purity and the yield of the p-hydroxyacetophenone are favorably improved.
Through a plurality of experiments, the method finds that when the final crystallization temperature of the cold crystallization is controlled to 97-103 ℃, the yield and the purity of the p-hydroxyacetophenone product can be further improved.
Further, the cooling frequency of the cold crystallization is 0.8-1.5 ℃/min.
In a specific embodiment, the cooling frequency of the cold crystallization can be 0.6 ℃/min, 0.8 ℃/min, 1.2 ℃/min, 1.5 ℃/min.
In some specific embodiments, the cooling frequency of the cold crystallization can be further 0.6-0.8 ℃/min, 0.6-1.2 ℃/min, 0.6-1.5 ℃/min, 0.8-1.2 ℃/min, 1.2-1.5 ℃/min.
According to experimental analysis, when the cooling frequency is more than 1.5 ℃/min, in the process that the p-hydroxyacetophenone in the molten liquid gradually precipitates crystals, the crystallization of the p-hydroxyacetophenone product is too fast due to the too fast cooling frequency, a large amount of impurities are wrapped in the p-hydroxyacetophenone, the subsequent sweating and purifying effects are reduced, and the purity of the p-hydroxyacetophenone product is obviously reduced; when the cooling frequency is less than 0.8 ℃/min, the purity and the yield of the p-hydroxyacetophenone product are not obviously improved, but the cooling time is longer, so that the production cost is improved. Therefore, the temperature reduction frequency is controlled within the range of 0.8-1.5 ℃/min.
Further, the cold crystallization treatment also comprises crystal growing, and the crystal growing time is 1-2h.
In a specific embodiment, the crystal growth time can be 1h, 1.5h and 2h.
In some specific embodiments, the crystal growth time can also be 1-1.5h and 1.5-2h.
When the cold crystallization reaches the final temperature, the crystal growing is carried out on the p-hydroxyacetophenone coarse crystal obtained by the cold crystallization treatment. As proved by experimental analysis, when the crystal growing time is controlled within the range, the purity and the yield of the p-hydroxyacetophenone product can be further improved. Therefore, the crystal growth time is controlled within the range.
In order to further effectively remove impurities in the crude crystals of p-hydroxyacetophenone, the purity of p-hydroxyacetophenone needs to be improved by heating and sweating treatment.
The temperature-rising sweating treatment is to slowly raise the temperature of the p-hydroxyacetophenone crude crystal at the final crystallization temperature of 97-103 ℃, and in the process, impurities are gradually removed. According to analysis, in the process of heating and sweating, the melting point of the local crystal layer with more impurities in the p-hydroxyacetophenone coarse crystal is lower, and the melting point of the local crystal layer with less impurities in the p-hydroxyacetophenone coarse crystal is higher. In the heating and sweating treatment process, the local crystal layer with more impurities can be firstly melted due to the lower melting point, and the melted impurities gradually form sweating liquid to flow out from the inside of the crystal, so that the impurities in the p-hydroxyacetophenone coarse crystal are effectively removed. Therefore, the temperature-rising sweating parameter condition needs to be reasonably controlled, the removal efficiency of impurities in the p-hydroxyacetophenone is improved, and meanwhile, the loss of the p-hydroxyacetophenone product can be reduced, so that the purity and the yield of the p-hydroxyacetophenone are favorably improved.
According to the technical scheme, in the temperature-rising sweating treatment, the temperature-rising frequency is 0.8-1.2 ℃/h, and the sweating final temperature is 107-110 ℃.
Furthermore, the temperature-rising frequency of the temperature-rising sweating is 0.9-1.1 ℃/h.
In a specific embodiment, the temperature-rising frequency of the temperature-rising sweating can be 0.8 ℃/h, 0.9 ℃/h, 1.0 ℃/h, 1.1 ℃/h, 1.2 ℃/h.
In some specific embodiments, the temperature raising frequency for raising temperature and sweating can also be 0.8-0.9 ℃/h, 0.8-1.0 ℃/h, 0.8-1.1 ℃/h, 0.9-1.0 ℃/h, 0.9-1.2 ℃/h, 1.0-1.1 ℃/h, 1.0-1.2 ℃/h.
According to experimental analysis, when the temperature rise frequency is more than 1.2 ℃/h, in the process of gradually melting low-melting-point impurities in the p-hydroxyacetophenone product, the excessive temperature rise frequency easily melts the p-hydroxyacetophenone product along with the impurities, so that the yield of the p-hydroxyacetophenone product is reduced; when the temperature rising frequency is less than 0.8 ℃/h, the purity and the yield of the p-hydroxyacetophenone product are not obviously improved, but the time required by temperature rising is longer, so that the cost is increased. Therefore, the temperature raising frequency is controlled in the range of 0.8-1.2 ℃/h. In a specific embodiment, the sweating terminal temperature may be 107 ℃, 109 ℃, 110 ℃.
In some specific embodiments, the sweating end temperature can also be 107-109 ℃ and 109-110 ℃.
In the test process, the low-melting-point impurities cannot be completely separated out when the final sweating temperature is lower than 105 ℃, so that the purity of the p-hydroxyacetophenone product is obviously reduced; when the final sweating temperature is higher than 110 ℃, the product is easy to melt together with impurities, so that the yield of the p-hydroxyacetophenone product is greatly reduced. Therefore, the present application controls the sweating terminal temperature to the above range.
Further, in the temperature-rising sweating, the monitoring method of the reaction process comprises the following steps:
and when the temperature rises to the sweating final temperature, sampling the sweating liquid every 40-80min, and detecting by gas chromatography, wherein when the purity of the p-hydroxyacetophenone in the sweating liquid is more than or equal to 99.90%, the sweating process is finished.
By means of the method, the information of the sweating process of the p-hydroxyacetophenone can be efficiently acquired, when the purity of the p-hydroxyacetophenone in the sweating liquid is larger than or equal to 99.90%, the purity of the p-hydroxyacetophenone product is larger than 99.90%, the monitoring reaction reaches the sweating end point at the moment, then the sweating step is timely ended, the melting of the p-hydroxyacetophenone product is reduced, and therefore the yield of the p-hydroxyacetophenone product is favorably improved.
Preferably, the purification method of the p-hydroxyacetophenone is carried out under the protection of inert gas.
Further, the inert gas is nitrogen.
According to experimental analysis, compared with a purification method without nitrogen protection, the method for purifying p-hydroxyacetophenone by using nitrogen protection can further improve the purity and yield of the p-hydroxyacetophenone product. Therefore, the present application chooses to use nitrogen for displacement protection. The test result is that because the phenolic hydroxyl group that p hydroxyacetophenone contains has reducibility, this application utilizes inert gas to protect p hydroxyacetophenone, has reduced p hydroxyacetophenone's side reaction, is favorable to improving p hydroxyacetophenone's purity. In addition, the inert gas of argon is expensive, and nitrogen is cheap and has wide sources, so the nitrogen is selected to be used for replacement protection.
Preferably, the cold crystallization treatment further comprises a purification treatment of the recovered crystallization mother liquor, and the specific method comprises the following steps:
when the purity of the p-hydroxyacetophenone in the crystallization mother liquor is more than or equal to 90.00%, cooling the crystallization mother liquor to be used as a next batch of raw materials;
and when the purity of the p-hydroxyacetophenone in the crystallization mother liquor is less than 90.00%, carrying out recrystallization treatment on the crystallization mother liquor, and using the crystallization mother liquor as a next batch of raw materials.
Preferably, the temperature-rising sweating treatment further comprises a purification treatment of using the recovered sweating as a next raw material.
The test results show that the total yield of the crude p-hydroxyacetophenone product is up to 97.90% or more, and the purity is higher than 99.97% after the total yield per pass and the recovery yield are summed up. Therefore, the crystallization mother liquor recovered by cold crystallization and the perspiration recovered by heating and sweating are used as the next raw materials, and the p-hydroxyacetophenone product with high purity and yield can be obtained after purification.
In a second aspect, the present application also provides a p-hydroxyacetophenone reagent prepared by the above purification method of p-hydroxyacetophenone; the purity of the p-hydroxyacetophenone reagent is more than or equal to 99.90 percent.
The melting point of the p-hydroxyacetophenone reagent prepared by the purification method of p-hydroxyacetophenone is 107.6-108.4 ℃.
By utilizing the purification method provided by the application, the p-hydroxyacetophenone product without impurities, residual organic solvent, low chroma and pungent smell can be obtained, and the product is favorable for widening the application field of the p-hydroxyacetophenone product.
To sum up, the technical scheme of this application has following effect:
by utilizing the purification method provided by the application, the p-hydroxyacetophenone product which is free of impurities and residual organic solvents, low in chromaticity and free of pungent smell can be obtained; and the purification method obviously improves the purity and yield of the p-hydroxyacetophenone product.
The purification method provided by the application does not need to use a solvent, shortens the production flow, avoids secondary pollution caused by other solvents, does not need to consider the cost of adding the solvent and the recovery problem, and effectively reduces the preparation cost of the p-hydroxyacetophenone product.
The purification method of p-hydroxyacetophenone provided by the application has mild process conditions and low test cost, and is suitable for kilogram-level industrial scale production.
This application is through the experimental parameter condition of control cold crystallization and intensification sweating to crystallization mother liquor and the sweat that intensification sweating was retrieved to cold crystallization recovery carry out the purification, utilize nitrogen replacement protection simultaneously, further improved the yield and the purity of p hydroxyacetophenone product.
Drawings
FIG. 1 is a gas chromatogram of p-hydroxyacetophenone product in example 3 of the present application.
Detailed Description
In a first aspect, the application provides a method for purifying p-hydroxyacetophenone, which specifically comprises the following steps:
s1: hot melting
And (3) putting the p-hydroxyacetophenone crude product into a crystallizer, heating the p-hydroxyacetophenone crude product to 115 +/-3 ℃, and completely melting the p-hydroxyacetophenone crude product to obtain molten liquid.
Wherein, the crude p-hydroxyacetophenone product is supposed to contain impurities of phenol, hydroquinone, o-hydroxyacetophenone and residual solvent of o-dichlorobenzene, and the purity of the crude p-hydroxyacetophenone product is 90.00-99.90%.
S2: cold crystallization
And carrying out cold crystallization treatment on the molten liquid to obtain coarse crystals.
Wherein, the parameter conditions of the cold crystallization treatment are as follows: the temperature reduction frequency is less than or equal to 1.5 ℃/min, the crystallization final temperature is 97-103 ℃, and the crystal growth time is 1-2h.
Furthermore, the temperature reduction frequency is 0.8-1.5 ℃/min.
In addition, the cold crystallization treatment step also comprises the purification treatment of the recovered crystallization mother liquor, and the specific method comprises the following steps:
when the purity of the p-hydroxyacetophenone in the crystallization mother liquor is more than or equal to 90.00 percent, cooling the crystallization mother liquor, and then using the crystallization mother liquor as the next batch of raw materials;
when the purity of the p-hydroxyacetophenone in the crystallization mother liquor is less than 90.00%, the crystallization mother liquor is subjected to recrystallization treatment and then used as the next batch of raw materials.
S3: temperature rising and sweating
And (4) heating and sweating the crude crystals in the crystallizer to obtain pure crystals.
Wherein the parameter conditions of the temperature-rising sweating treatment are as follows: the heating frequency is 0.8-1.2 ℃/h, and the final sweating temperature is 107-110 ℃.
Specifically, the monitoring method of the temperature-rising sweating reaction process comprises the following steps:
when the temperature rises to the final sweating temperature, the sweating liquid is sampled every 40-80min, and the gas chromatography detection shows that the purity of the p-hydroxyacetophenone in the sweating liquid is more than or equal to 99.90 percent, which indicates that the purity of the product in the crystallizer is more than 99.90 percent, and the sweating process is finished at this moment.
Furthermore, the temperature-rising sweating treatment also comprises purification treatment by taking the recovered sweating as a next batch of raw materials.
S4: heating, melting and spray cooling
Heating the crystallizer to 115 +/-3 ℃, and cooling the product in a spraying and condensing mode after the solid material in the crystallizer is melted to obtain the p-hydroxyacetophenone product.
In addition, the purification method of the p-hydroxyacetophenone is carried out under the protection of inert gas; further, the inert gas is nitrogen.
In a second aspect, the present application also provides a p-hydroxyacetophenone reagent prepared by the above purification method of p-hydroxyacetophenone; the purity of the p-hydroxyacetophenone reagent is more than or equal to 99.90 percent.
The present application is described in further detail below in connection with examples 1-16, comparative examples 1-8, and performance testing tests, which are not to be construed as limiting the scope of the claimed application.
Examples
Examples 1 to 10
Examples 1-10 each provide a method for purifying p-hydroxyacetophenone.
The above embodiments differ in that: and (3) parameter conditions of cold crystallization. The details are shown in Table 1.
The implementation method of the embodiment specifically includes the following steps:
s1: hot melting
Adding 250kg of p-hydroxyacetophenone crude product with the purity of 99.05% into a 2000L crystallizer, replacing the crude product with nitrogen for protection, and heating to 115 +/-3 ℃ to completely melt the p-hydroxyacetophenone crude product to obtain molten liquid;
wherein, the preparation method of the crude p-hydroxyacetophenone is as follows (refer to chemical reagent 1993, 15 (4): 254): taking phenol and acetic anhydride as raw materials, and carrying out esterification and concentration processes to obtain phenyl acetate; and then adding o-dichlorobenzene to react under the catalysis of aluminum trichloride, distilling by using water vapor, cooling and crystallizing, and rectifying and recrystallizing to obtain a crude product of the p-hydroxyacetophenone, wherein the purity of the crude product of the p-hydroxyacetophenone is 99.05 percent, the melting point of the crude product of the p-hydroxyacetophenone is 102.3-106.7 ℃, namely the melting range of the crude product of the p-hydroxyacetophenone is 4.4 ℃. Supposing that the crude p-hydroxyacetophenone contains impurities of phenol, hydroquinone, o-hydroxyacetophenone and residual organic solvent of o-dichlorobenzene.
S2: cold crystallization
According to the parameter conditions of cold crystallization in the table 1, the temperature of the crystallizer is reduced to the final crystallization temperature according to the temperature reduction frequency, and then the crystal is grown at the temperature, so that the molten liquid is solidified again to obtain coarse crystals; recovering the crystallization mother liquor, detecting the crystallization mother liquor by using a gas chromatography, cooling the crystallization mother liquor when the purity of the p-hydroxyacetophenone in the crystallization mother liquor is more than or equal to 90.00 percent, and using the crystallization mother liquor as a next batch of raw materials; when the purity of the p-hydroxyacetophenone in the crystallization mother liquor is less than 90.00%, the crystallization mother liquor is subjected to recrystallization treatment and then used as a next batch of raw materials.
S3: temperature rising and sweating
Raising the temperature of the crystallizer to 107 ℃ at the temperature raising frequency of 1 ℃/h, gradually reserving sweat at a discharge port in the process, sampling and detecting the sweat at intervals of 60min, detecting the sweat by using a gas chromatography, and when the purity of p-hydroxyacetophenone in the sweat is more than or equal to 99.90%, indicating that the purity of a product in the crystallizer is more than 99.90%, and ending the sweating process to obtain pure crystals; collecting the sweat, and then purifying the sweat as the next batch of raw materials.
S4: heating, melting and spray cooling
Heating the crystallizer to 115 +/-3 ℃, and cooling the product in a spraying and condensing mode after the solid material in the crystallizer is melted to obtain the p-hydroxyacetophenone product.
TABLE 1 Parametric conditions for cold crystallization in examples 1-10
Examples 11 to 14
Examples 11-14 each provide a method for purifying p-hydroxyacetophenone.
The above embodiments are different from embodiment 3 in that: raising the temperature to generate sweat. Specifically, as shown in table 2.
TABLE 2 temperature-elevating sweating parameter conditions in examples 3, 11-14
Example 15
This example provides a method for purifying p-hydroxyacetophenone.
The present embodiment is different from embodiment 3 in that: this example was not blanketed with nitrogen.
Comparative example
Comparative example 1
This comparative example provides a method for purifying p-hydroxyacetophenone.
The specific steps of the purification method of p-hydroxyacetophenone in the comparative example are as follows:
s1 dissolution
Adding a mixed solvent of 500kg of deionized water and 80kg of isopropanol into 250kg of p-hydroxyacetophenone crude product with the purity of 99.05%, heating to 50 ℃, and stirring until the p-hydroxyacetophenone crude product is completely dissolved to obtain a p-hydroxyacetophenone crude product solution; wherein the crude product of the p-hydroxyacetophenone contains the impurities of phenol, hydroquinone, o-hydroxyacetophenone and residual organic solvent of o-dichlorobenzene.
S2 decolorization
And (2) adding 4kg of activated carbon into the p-hydroxyacetophenone crude product solution obtained in the step (S1), keeping the temperature and decoloring for 2h, and filtering off the activated carbon by using a filter to obtain a decoloring solution.
S3 crystal
And (3) slowly cooling the decolorized solution obtained in the step (S2) to 0 ℃ for crystallization, collecting the centrifuged material after the crystallization is finished, leaching the centrifuged material with a small amount of ice water, and drying the washed material at 50 ℃ for 7 hours to obtain the p-hydroxyacetophenone product.
Comparative examples 2 to 8
Comparative examples 2 to 8 each provide a method for purifying p-hydroxyacetophenone.
The above comparative examples differ from example 3 in that: cold crystallization and warm sweating. Specifically, the results are shown in Table 3.
The method for monitoring the temperature-rising sweating reaction process in each proportion comprises the following steps: and (3) sampling and detecting the sweating liquid every 60min after the temperature is raised to the sweating final temperature, and when the purity of the p-hydroxyacetophenone in the sweating liquid is not changed any more, indicating that the purity of the product in the crystallizer can not be further improved, and ending the sweating process at this moment. TABLE 3 Parametric conditions for cold crystallization and elevated temperature sweating in comparative examples 2 to 8
Performance test
1. Performance detection of one-way purification method of p-hydroxyacetophenone
(1) One-way yield and purity of p-hydroxyacetophenone product
The purification methods of p-hydroxyacetophenone provided in examples 1 to 15 and comparative examples 1 to 8 were used as the test subjects, and the single-pass yield and purity of the purified p-hydroxyacetophenone product were tested.
And (3) detection results: the purity of the p-hydroxyacetophenone product of example 3 is shown in fig. 1. The per-pass yields and purities of the p-hydroxyacetophenone products of examples 1 to 15 and comparative examples 1 to 8 are shown in Table 4.
By analyzing the gas chromatogram in FIG. 1, it was found that the purity of p-hydroxyacetophenone product obtained in example 3 of the present application was 99.985%. The detection result shows that the purity of the p-hydroxyacetophenone product can be effectively improved by using the purification method provided by the application.
TABLE 4 yield and purity of p-hydroxyacetophenone product in examples 1 to 15 and comparative examples 1 to 8
With reference to table 4, according to the detection results of comparative examples 1 to 15 and comparative examples 1 to 8, the application heats and melts the p-hydroxyacetophenone crude product, and obtains the p-hydroxyacetophenone product through cold crystallization and heating sweating treatment; by utilizing the purification method, the p-hydroxyacetophenone product with the purity higher than 99.90 percent and the single-pass yield higher than 77 percent can be obtained. The detection result shows that the yield and the purity of the p-hydroxyacetophenone product are obviously improved by using the purification method.
By comparing the test results of example 3 and comparative example 1, when the recrystallization method is used for purifying p-hydroxyacetophenone, the yield of p-hydroxyacetophenone is only 67.64% and the purity is only 97.36%; by utilizing the purification method provided by the application, the yield and the purity of the p-hydroxyacetophenone product can be obviously improved.
By comparing the detection results of the examples 1-4 and the comparative example 2, when the cooling frequency is more than 1.5 ℃/min, the yield and the purity of the p-hydroxyacetophenone product are low, so that the cooling frequency is controlled within the range of less than or equal to 1.5 ℃/min. Further, when the temperature reduction frequency is less than 0.8 ℃/min, the purity and the yield of the p-hydroxyacetophenone product are not obviously improved, but the time required for temperature reduction is longer, so that the cost is increased. Therefore, the temperature reduction frequency is controlled within the range of 0.8-1.5 ℃/min.
By comparing the test results of examples 3, 5-6 and comparative examples 3-4, the yield and purity of p-hydroxyacetophenone product can be further improved when the final temperature of crystallization is controlled in the range of 97-103 ℃. Therefore, the present application controls the crystallization final temperature within the above range.
Through the detection results of comparative examples 3 and 7-10, compared with the method that crystal growing is not carried out in the purification method, the crystal growing time is selected to be controlled within the range of 1-2h, so that the yield and the purity of the p-hydroxyacetophenone product can be further improved. Therefore, the crystal growth time is controlled within the range.
By comparing the detection results of the examples 3, 11-12 and the comparative examples 5-6, when the temperature rising frequency is more than 1.2 ℃/h, the yield of the p-hydroxyacetophenone product is low; when the temperature rising frequency is less than 0.8 ℃/h, the purity and the yield of the p-hydroxyacetophenone product are not obviously improved, but the time required by temperature rising is longer, so that the cost is increased. Therefore, the temperature raising frequency is controlled in the range of 0.8-1.2 ℃/h.
By comparing the results of the tests of examples 3, 13-14 and comparative examples 7-8, the yield of p-hydroxyacetophenone product was low when the sweating final temperature was more than 110 ℃ and the time required for sweating was long when the sweating final temperature was less than 107 ℃ and the yield of p-hydroxyacetophenone product was only 97.23%. Therefore, the application controls the final sweating temperature to be in the range of 107-110 ℃.
According to the test results of comparative examples 3 and 15, when nitrogen protection is not performed in the method for purifying p-hydroxyacetophenone, the purity and yield of the p-hydroxyacetophenone product are low; and this application utilizes nitrogen gas to carry out the replacement protection, can further improve the purity and the yield of p hydroxyacetophenone product, consequently, this application selects to utilize nitrogen gas to carry out the replacement protection.
(2) Melting point of p-hydroxyacetophenone product
The melting point of p-hydroxyacetophenone product provided in examples 1 to 15 and comparative examples 1 to 8 was examined with the p-hydroxyacetophenone product as an examination object.
The detection method comprises the following steps: grinding a sample of a p-hydroxyacetophenone product into fine powder, drying the fine powder at a constant temperature of 60 +/-2 ℃ under reduced pressure to constant weight, placing the dried product in a dryer to room temperature, placing the dried product on a white dropping board or clean paper, placing the dried product in a capillary tube, vertically placing the capillary tube on a table top by means of a clean glass tube with an appropriate length, placing the capillary tube from the upper opening to enable the capillary tube to freely fall down, repeating the steps for a plurality of times, enabling the powder to be tightly aggregated at the sealing and melting end of the capillary tube, and enabling the height of the sample to be 3-5mm; starting a YRT-3 melting point tester, when the temperature of the capillary is raised to 98 ℃, putting the capillary filled with the sample into the YRT-3 melting point tester, continuously heating, adjusting the temperature rise rate to be 1.0-1.5 ℃/min, recording the initial melting temperature value and the final melting temperature value of the p-hydroxyacetophenone product, repeatedly measuring for 3 times, and taking the average value.
And (3) detection results: as shown in table 4.
In combination with Table 4, it can be seen that the melting range of p-hydroxyacetophenone products in comparative examples 1 to 8 is higher than 1.0 ℃; the melting point of the p-hydroxyacetophenone product in examples 1-15 is in the range of 107.6-108.4 ℃, i.e., the p-hydroxyacetophenone product with a melting range of less than 0.9 ℃ is obtained by the purification method provided by the present application.
(3) Color and state of p-hydroxyacetophenone product
Taking the unpurified crude p-hydroxyacetophenone product and the p-hydroxyacetophenone products provided in examples 1 to 15 and comparative examples 1 to 8 as detection objects, and observing the color and the state of the crude p-hydroxyacetophenone product/the p-hydroxyacetophenone product; then respectively dissolving 1g of the crude p-hydroxyacetophenone product/p-hydroxyacetophenone product in 10mL of isopropanol, and observing the color and the state of the solution of the crude p-hydroxyacetophenone product/p-hydroxyacetophenone product after the crude p-hydroxyacetophenone product/p-hydroxyacetophenone product is fully dissolved.
After observation, the unpurified crude p-hydroxyacetophenone is a white-like to white solid, and after the crude p-hydroxyacetophenone is dissolved in alcohol, the crude p-hydroxyacetophenone solution is in a yellow and slightly turbid state; the p-hydroxyacetophenone product in comparative examples 1 to 8 was a white crystal; after the product is dissolved in alcohol, the p-hydroxyacetophenone product solution is in a light yellow and transparent state; in embodiments 1 to 15 of the present application, the p-hydroxyacetophenone product is a white crystal, and after the product is dissolved in alcohol, the p-hydroxyacetophenone product solution is colorless and transparent, which means that the purification method provided by the present application can significantly reduce the color of p-hydroxyacetophenone and provide a p-hydroxyacetophenone product with low chroma and high product quality.
Example 16
This example provides a method for purifying p-hydroxyacetophenone.
The present embodiment is different from embodiment 3 in that: the raw material of p-hydroxyacetophenone crude product was a mixture of the crystallization mother liquor of example 3 and perspiration, and after cooling, 42.1kg of crude product was obtained, in which the purity of p-hydroxyacetophenone was 93.40%.
Performance test
2. Recovery yield and purity of crystallization mother liquor and perspiration liquid
With the purification method of p-hydroxyacetophenone of example 16 as an object of detection, the recovery yield and purity of the purified p-hydroxyacetophenone product were detected; meanwhile, the single-pass yield of the p-hydroxyacetophenone product in example 3 and the recovery yield of the p-hydroxyacetophenone product in example 16 are counted as example 3+16.
And (3) detection results: as shown in table 5.
TABLE 5 yield and purity of p-hydroxyacetophenone product in examples 3 and 16
With reference to table 5, it can be seen from the results of comparing example 3 with example 16 that the recovery yield of the p-hydroxyacetophenone product is 88.17% and the purity is 99.96% by recovering and purifying the crystallization mother liquor and the perspiration liquid in example 3; and after the total once-through yield and the recovery yield are calculated, the total yield of the p-hydroxyacetophenone product is 97.96 percent, and the purity is 99.97 percent. The detection results show that the purification method provided by the application can further improve the total yield of the p-hydroxyacetophenone product after single-pass purification and recovery purification.
Although the invention has been described in detail with respect to the general description and the specific embodiments thereof, it will be apparent to those skilled in the art that modifications and improvements can be made based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (10)
1. The method for purifying the p-hydroxyacetophenone is characterized by comprising the following steps:
heating and melting the p-hydroxyacetophenone crude product to obtain a molten liquid;
sequentially carrying out cold crystallization and heating sweating treatment on the molten liquid to obtain a p-hydroxyacetophenone product;
wherein, in the cold crystallization treatment: the temperature reduction frequency is less than or equal to 1.5 ℃/min, and the final crystallization temperature is 97-103 ℃;
in the temperature-rising sweating treatment: the temperature rising frequency is 0.8-1.2 ℃/h, and the sweating final temperature is 107-110 ℃.
2. The method for purifying p-hydroxyacetophenone according to claim 1, characterized in that the temperature for the melting at elevated temperature is 115 ± 3 ℃.
3. The method for purifying p-hydroxyacetophenone according to claim 1, characterized in that the cooling frequency of the cold crystallization is 0.8 to 1.5 ℃/min.
4. The method for purifying p-hydroxyacetophenone according to claim 1, wherein the cold crystallization treatment further comprises crystal growth, and the crystal growth time is 1-2h.
5. The method for purifying p-hydroxyacetophenone according to claim 1, characterized in that the temperature rising frequency of the temperature rising sweating is 0.9-1.1 ℃/h.
6. The method for purifying p-hydroxyacetophenone according to claim 1, characterized in that the purification method of p-hydroxyacetophenone is performed under inert gas protection.
7. The method for purifying p-hydroxyacetophenone according to claim 6, characterized in that the inert gas is nitrogen.
8. The method for purifying p-hydroxyacetophenone according to claim 1, characterized in that the cold crystallization treatment further comprises a purification treatment of the recovered crystallization mother liquor, which comprises the following steps:
when the purity of the p-hydroxyacetophenone in the crystallization mother liquor is more than or equal to 90.00%, cooling the crystallization mother liquor to be used as a next batch of raw materials;
and when the purity of the p-hydroxyacetophenone in the crystallization mother liquor is less than 90.00%, carrying out recrystallization treatment on the crystallization mother liquor, and using the crystallization mother liquor as a next batch of raw materials.
9. The method for purifying p-hydroxyacetophenone according to claim 1, wherein the temperature-raising sweating treatment further comprises purification treatment using the recovered sweating as a starting material for the next batch.
10. A p-hydroxyacetophenone reagent prepared by the method for purifying p-hydroxyacetophenone according to any one of claims 1 to 9; the purity of the p-hydroxyacetophenone reagent is more than or equal to 99.90 percent.
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