CN109320408B - Refining method of 4- (4-formylphenoxy) benzaldehyde - Google Patents
Refining method of 4- (4-formylphenoxy) benzaldehyde Download PDFInfo
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- CN109320408B CN109320408B CN201811339171.1A CN201811339171A CN109320408B CN 109320408 B CN109320408 B CN 109320408B CN 201811339171 A CN201811339171 A CN 201811339171A CN 109320408 B CN109320408 B CN 109320408B
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- C07C45/78—Separation; Purification; Stabilisation; Use of additives
- C07C45/80—Separation; Purification; Stabilisation; Use of additives by liquid-liquid treatment
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- 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
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Abstract
The invention relates to the technical field of chemical synthesis, and particularly discloses a refining method of 4- (4-formylphenoxy) benzaldehyde. Treating chloralkane solution of a 4- (4-formylphenoxy) benzaldehyde crude product by using dilute alkali solution, washing with purified water to remove residual alkali liquor, standing for liquid separation, adding a stabilizing agent into an oil phase, carrying out reduced pressure concentration to remove chloralkane, then adding an alcohol solvent, stirring, heating for dissolution, adding purified water, stirring, cooling for crystallization, filtering, washing and drying to obtain a 4- (4-formylphenoxy) benzaldehyde refined product. The purity of the 4- (4-formylphenoxy) benzaldehyde product prepared by the invention can reach more than 99.9%, the yield can reach more than 96%, the concentration of a single metal ion is less than or equal to 0.5ppm, the requirements of the standard of electronic grade products on the purity and the concentration of the metal ion can be met, and the method has wide application prospect.
Description
Technical Field
The invention relates to the technical field of chemical synthesis, in particular to a refining method of 4- (4-formylphenoxy) benzaldehyde.
Background
4- (4-formylphenoxy) benzaldehyde having the structural formula:
engineering materials prepared by taking the material as a raw material are widely applied to various fields of electronics, solar energy, photovoltaic power generation, aviation, aerospace and the like. Among them, 4- (4-formylphenoxy) benzaldehyde used in the field of electronic technology is required to have characteristics of high purity (99.9% content) and low concentration of single metal ions (content less than or equal to 0.5 ppm).
At present, a small amount of synthetic raw materials generally remain in 4- (4-formylphenoxy) benzaldehyde prepared by conventional reaction, and self-polymerization reaction or aldol condensation reaction with a recrystallization solvent may also occur in the 4- (4-formylphenoxy) benzaldehyde in the subsequent delicate process, so that the purity (HPLC) of a crude product of the 4- (4-formylphenoxy) benzaldehyde is difficult to reach more than 99.5%; in addition, a small amount of inorganic catalyst residues and a small amount of metal ions are introduced into the raw material in the crude 4- (4-formylphenoxy) benzaldehyde product, so that the concentration of a single metal ion in the crude 4- (4-formylphenoxy) benzaldehyde product is generally over 10ppm, and the requirements of electronic-grade products on purity (more than 99.5%) and metal ion concentration (the concentration of a single metal ion is less than 1ppm) can not be met.
Disclosure of Invention
Aiming at the problems that the 4- (4-formylphenoxy) benzaldehyde obtained in the prior art is difficult to meet the requirements of the purity (more than 99.5%) of an electronic-grade product and the concentration (less than 1ppm) of metal ions and the like, the invention provides a refining method of the 4- (4-formylphenoxy) benzaldehyde.
In order to solve the technical problems, the technical scheme provided by the invention is as follows:
a refining method of 4- (4-formylphenoxy) benzaldehyde comprises the following steps:
uniformly mixing a 4- (4-formylphenoxy) benzaldehyde crude product with chloralkane, adding a dilute alkali solution, fully stirring, standing for layering after reaction is finished, removing a water phase, washing with purified water to be neutral, and collecting an oil phase;
step two, adding a stabilizing agent into the oil phase, and carrying out reduced pressure concentration to remove chloralkane to obtain a concentrate;
and step three, adding an alcohol solvent into the concentrate, stirring, heating to dissolve, adding purified water, stirring, cooling to crystallize, filtering, washing and drying to obtain a finished product of the 4- (4-formylphenoxy) benzaldehyde essence.
Compared with the prior art, the refining method of 4- (4-formylphenoxy) benzaldehyde provided by the invention adopts dilute alkali solution to remove p-hydroxybenzaldehyde contained in the crude product of 4- (4-formylphenoxy) benzaldehyde, and then uses purified water to wash out the residual alkali in chloralkane; adding a trace amount of stabilizer when the chloralkane is distilled off to inhibit the self-condensation of the 4- (4-formylphenoxy) benzaldehyde and simultaneously prevent the aldol condensation reaction of the 4- (4-formylphenoxy) benzaldehyde and alcohol solvent when the 4- (4-formylphenoxy) benzaldehyde is recrystallized; adding alcohol solvent and water for cooling and crystallization, and effectively removing metal ions in the 4- (4-formylphenoxy) benzaldehyde crude product. According to the refining method of 4- (4-formylphenoxy) benzaldehyde provided by the invention, the yield of the prepared 4- (4-formylphenoxy) benzaldehyde product can reach more than 96%, the purity can reach more than 99.9%, the concentration of single metal ions is less than or equal to 0.5ppm by optimizing the refining process, the requirements of the standard of electronic-grade products on the purity and the concentration of the metal ions are met, and a foundation is laid for realizing industrial production of the electronic-grade 4- (4-formylphenoxy) benzaldehyde.
Preferably, in the first step, the mass ratio of the 4- (4-formylphenoxy) benzaldehyde crude product to the chloralkane is 1: 2-5.
The preferred mass ratio of the crude 4- (4-formylphenoxy) benzaldehyde to chloroalkane is that the crude 4- (4-formylphenoxy) benzaldehyde is sufficiently dissolved to facilitate subsequent removal of various impurities from the crude 4- (4-formylphenoxy) benzaldehyde.
Preferably, the chloralkane is one of dichloromethane, trichloromethane or dichloroethane.
More preferably, the chloroalkane is dichloromethane.
The preferred chloralkane has higher solubility to the crude 4- (4-formylphenoxy) benzaldehyde, so that the crude 4- (4-formylphenoxy) benzaldehyde can be quickly dissolved.
Preferably, in the first step, the addition amount of the dilute alkali solution is 28-33% of the mass of the chloralkane.
The addition amount of the optimized dilute alkali solution ensures that the p-hydroxybenzaldehyde in the 4- (4-formylphenoxy) benzaldehyde crude product is fully removed, and simultaneously, the washing times for removing residual alkali liquor subsequently can be reduced, the consumption of purified water is reduced, the refining efficiency is improved, and the energy consumption is reduced.
Preferably, the dilute alkali solution is 0.2-1 wt% of sodium hydroxide solution.
The 0.2-1 wt% sodium hydroxide solution can fully react with the p-hydroxybenzaldehyde on the premise of introducing impurities as little as possible, and is favorable for washing subsequent purified water to remove residual sodium hydroxide.
Preferably, in the second step, the stabilizer is one of potassium carbonate, sodium carbonate or sodium hydroxide.
More preferably, the stabilizer is potassium carbonate.
The preferable stabilizing agent can ensure that the 4- (4-formylphenoxy) benzaldehyde has good stability at higher temperature, effectively inhibit the self-condensation of the 4- (4-formylphenoxy) benzaldehyde and prevent the aldol condensation reaction of the 4- (4-formylphenoxy) benzaldehyde and alcohol solvent during recrystallization.
Preferably, the addition amount of the stabilizer is two to six parts per million of the mass of the crude 4- (4-formylphenoxy) benzaldehyde.
The preferable adding amount of the stabilizer can effectively improve the stability of the 4- (4-formylphenoxy) benzaldehyde and reduce side reactions possibly occurring at high temperature on the premise of ensuring that impurities are introduced as little as possible, thereby improving the purity of the 4- (4-formylphenoxy) benzaldehyde product.
Preferably, in the step one, the reaction temperature is 10-30 ℃, and the reaction time is 0.5-1 h.
The preferable reaction temperature can accelerate the reaction speed, reduce the reaction time and simultaneously reduce the occurrence of side reactions,
preferably, in the second step, the pressure of the reduced pressure concentration is-0.099 to-0.08 MPa, and the temperature is 30 to 50 ℃.
The preferable reduced pressure concentration condition can reduce self-condensation of 4- (4-formylphenoxy) benzaldehyde, and can remove chloralkane solvent as soon as possible to improve refining efficiency. The distilled chloralkane can be directly recycled, thus saving the cost.
Preferably, in the third step, the mass ratio of the alcohol solvent to the crude 4- (4-formylphenoxy) benzaldehyde product is 3-6: 1.
The mass ratio of the preferable alcohol solvent to the crude 4- (4-formylphenoxy) benzaldehyde can fully dissolve 4- (4-formylphenoxy) benzaldehyde.
Preferably, in the third step, the alcohol solvent is one of methanol, ethanol or isopropanol.
The preferable alcohol solvent not only has better solubility for the crude product of the 4- (4-formylphenoxy) benzaldehyde and can fully dissolve the crude product of the 4- (4-formylphenoxy) benzaldehyde, but also has better dissolving capacity for the residual inorganic catalyst in the crude product of the 4- (4-formylphenoxy) benzaldehyde and metal ions introduced by raw materials by adding purified water into the alcohol solution, can fully remove the metal ions in the crude product of the 4- (4-formylphenoxy) benzaldehyde and reduce the concentration of single metal ions in the crude product of the 4- (4-formylphenoxy) benzaldehyde.
Preferably, in the third step, the temperature for heating and dissolving is 50-60 ℃.
The dissolving temperature of the 4- (4-formylphenoxy) benzaldehyde crude product is controlled at 50-60 ℃, and the self condensation reaction of the 4- (4-formylphenoxy) benzaldehyde is reduced on the premise of ensuring that the 4- (4-formylphenoxy) benzaldehyde is fully dissolved.
Preferably, in the third step, the temperature for cooling and crystallizing is 5-15 ℃.
The preferable crystallization temperature can ensure that the 4- (4-formylphenoxy) benzaldehyde is fully precipitated, the yield of the product is improved, the precipitation of metal ions can be avoided, and the purity of the product is improved.
Preferably, in the third step, the mass ratio of the purified water to the alcohol solvent is 0.5-1: 1.
The preferable alcohol-water ratio can ensure that the 4- (4-formylphenoxy) benzaldehyde and metal ions have higher solubility, thereby being beneficial to cooling crystallization and removing the metal ions as much as possible.
The crystallized alcohol-water solution can be directly used for purifying a crude product for the next time, the crude product is recycled and reused for more than three times, and if the alcohol-water solution used for more than 3 times contains more impurities, the pure alcohol-water solution can be prepared by a rectification method, so that the cost is saved.
Preferably, in the third step, the drying is vacuum drying, and the drying temperature is 30-50 ℃.
The preferable drying condition can avoid the 4- (4-formylphenoxy) benzaldehyde from being oxidized and undergoing self-condensation reaction, thereby improving the quality of the product.
According to the refining method of 4- (4-formylphenoxy) benzaldehyde provided by the invention, the obtained product can meet the requirements of electronic grade product standards on purity and metal ions, a foundation is laid for realizing industrial production of electronic grade 4- (4-formylphenoxy) benzaldehyde, and dichloromethane and alcohol aqueous solution used in the refining process are common solvents and are easy to recycle; the stabilizer is a common reagent, and has the advantages of small dosage, low price and low production cost.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1
A refining method of 4- (4-formylphenoxy) benzaldehyde comprises the following steps:
step one, adding 6Kg of crude 4- (4-formylphenoxy) benzaldehyde and 30Kg of dichloromethane into a 50L glass reaction kettle provided with a heating jacket, mechanical stirring and a reflux condenser, stirring for dissolving, then adding 9Kg of 0.5 wt% sodium hydroxide solution, stirring for reacting for 30min at 10 ℃, standing for 1h, separating, transferring an oil layer into a 100L glass reaction kettle, washing the oil layer to be neutral by 30Kg of pure water respectively, standing for separating, and collecting an oil phase;
step two, transferring the obtained oil phase into a 50L glass reaction kettle, adding 24mg of potassium carbonate, controlling the vacuum at-0.099 MPa and the temperature at 50 ℃, and evaporating the dichloromethane solvent to dryness to obtain a concentrate;
and step three, adding 36kg of methanol into the concentrate, heating to 55 ℃, stirring and dissolving, transferring to a 100L crystallization kettle, keeping the temperature at 55 ℃, adding 36kg of pure water, cooling to 15 ℃, filtering, and washing a filter cake with a methanol solution. And (3) drying the filter cake for 8 hours in vacuum at 45 ℃ to obtain 5808g of a refined product, wherein the yield is 96.8%, the appearance is white crystal, the purity is 99.95%, and the content of a single metal ion is less than or equal to 0.5 ppm.
Example 2
A refining method of 4- (4-formylphenoxy) benzaldehyde comprises the following steps:
step one, adding 6Kg of crude 4- (4-formylphenoxy) benzaldehyde and 12Kg of trichloromethane into a 50L glass reaction kettle provided with a heating jacket, mechanical stirring and a reflux condenser, stirring for dissolving, then adding 3.4Kg of 0.2 wt% sodium hydroxide solution, stirring for reacting for 1h at 15 ℃, standing for 1h, separating, transferring an oil layer into a 100L glass reaction kettle, washing the oil layer to be neutral by 30Kg of pure water respectively, standing for separating, and collecting an oil phase;
step two, transferring the obtained oil phase into a 50L glass reaction kettle, adding 12mg of sodium carbonate, controlling the vacuum to be 0.08MPa and the temperature to be 30 ℃, and evaporating the trichloromethane solvent to dryness to obtain a concentrate;
and step three, adding 18kg of ethanol into the concentrate, heating to 50 ℃, stirring for dissolving, transferring to a 100L crystallization kettle, keeping the temperature at 50 ℃, adding 14.4kg of pure water, cooling to 10 ℃, filtering, and washing a filter cake with an ethanol solution. And (3) drying the filter cake for 8 hours in vacuum at 30 ℃ to obtain 5760g of a refined product, wherein the yield is 96%, the appearance is white crystal, the purity is 99.92%, and the content of a single metal ion is less than or equal to 0.5 ppm.
Example 3
A refining method of 4- (4-formylphenoxy) benzaldehyde comprises the following steps:
step one, adding 6Kg of crude 4- (4-formylphenoxy) benzaldehyde and 24Kg of dichloroethane into a 50L glass reaction kettle provided with a heating jacket, mechanical stirring and a reflux condenser, stirring for dissolving, then adding 7.9Kg of 1 wt% sodium hydroxide solution, stirring for reacting for 30min at the temperature of 30 ℃, standing for 1h, separating, transferring an oil layer into a 100L glass reaction kettle, respectively washing the oil layer to be neutral by 30Kg of pure water, standing for separating, and collecting an oil phase;
step two, transferring the obtained oil phase into a 50L glass reaction kettle, adding 36mg of sodium hydroxide, controlling the vacuum at-0.09 MPa and the temperature at 40 ℃, and evaporating the dichloroethane solvent to dryness to obtain a concentrate;
and step three, adding 30kg of isopropanol into the concentrate, heating to 60 ℃, stirring for dissolving, transferring to a 100L crystallization kettle, keeping the temperature at 60 ℃, adding 15kg of pure water, cooling to 5 ℃, filtering, and washing a filter cake with an isopropanol solution. And (3) drying the filter cake for 8 hours in vacuum at 50 ℃ to obtain 5784g of a refined product, wherein the yield is 96.4%, the appearance is white crystal, the purity is 99.94%, and the content of a single metal ion is less than or equal to 0.5 ppm.
The 4- (4-formylphenoxy) benzaldehyde prepared in examples 1 to 3 was measured for its content and concentration of individual metal ions, and the results are shown in Table 1.
TABLE 1
In conclusion, the refining method of 4- (4-formylphenoxy) benzaldehyde provided by the invention has the advantages of simple process, no need of special equipment, low energy consumption and less side reaction, the purity of the prepared 4- (4-formylphenoxy) benzaldehyde product can reach more than 99.9%, the yield can reach more than 96%, the concentration of a single metal ion is less than or equal to 0.5ppm, the requirements of the standard of electronic grade products on the purity and the concentration of the metal ion can be met, and the refining method has wide application prospect.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents or improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (9)
1. A refining method of 4- (4-formylphenoxy) benzaldehyde is characterized in that: the method comprises the following steps:
uniformly mixing a 4- (4-formylphenoxy) benzaldehyde crude product with chloralkane, adding a dilute alkali solution, fully stirring, standing for layering after reaction is finished, removing a water phase, washing with purified water to be neutral, and collecting an oil phase;
step two, adding a stabilizing agent into the oil phase, and carrying out reduced pressure concentration to remove chloralkane to obtain a concentrate; the stabilizer is one of potassium carbonate, sodium carbonate or sodium hydroxide;
adding an alcohol solvent into the concentrate, stirring, heating for dissolving, adding purified water, stirring, cooling for crystallizing, filtering, washing and drying to obtain a finished product of the 4- (4-formylphenoxy) benzaldehyde essence; the alcohol solvent is one of methanol, ethanol or isopropanol.
2. The method of purifying 4- (4-formylphenoxy) benzaldehyde according to claim 1, wherein: in the first step, the mass ratio of the 4- (4-formylphenoxy) benzaldehyde crude product to the chloralkane is 1: 2-5.
3. The method of purifying 4- (4-formylphenoxy) benzaldehyde according to claim 1 or 2, wherein: the chloralkane is one of dichloromethane, trichloromethane or dichloroethane.
4. The method of purifying 4- (4-formylphenoxy) benzaldehyde according to claim 1, wherein: in the first step, the addition amount of the dilute alkali solution is 28-33% of the mass of the chloralkane; and/or
The dilute alkali solution is 0.2-1 wt% of sodium hydroxide solution.
5. The method of purifying 4- (4-formylphenoxy) benzaldehyde according to claim 1, wherein: the addition amount of the stabilizer is two to six parts per million of the mass of the crude 4- (4-formylphenoxy) benzaldehyde.
6. The method of purifying 4- (4-formylphenoxy) benzaldehyde according to claim 1, wherein: in the first step, the reaction temperature is 10-30 ℃, and the reaction time is 0.5-1 h;
in the second step, the pressure of the reduced pressure concentration is-0.099 to-0.08 MPa, and the temperature is 30 to 50 ℃.
7. The method of purifying 4- (4-formylphenoxy) benzaldehyde according to claim 1, wherein: in the third step, the mass ratio of the alcohol solvent to the crude 4- (4-formylphenoxy) benzaldehyde product is 3-6: 1.
8. The method of purifying 4- (4-formylphenoxy) benzaldehyde according to claim 1, wherein: in the third step, the temperature for heating and dissolving is 50-60 ℃; and/or
The temperature for cooling and crystallizing is 5-15 ℃.
9. The method for purifying 4- (4-formylphenoxy) benzaldehyde according to claim 1, wherein in the third step, the mass ratio of the purified water to the alcohol solvent is 0.5 to 1: 1; and/or
The drying is vacuum drying, and the drying temperature is 30-50 ℃.
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| CN106946744A (en) * | 2017-03-17 | 2017-07-14 | 上海交通大学 | A kind of new PTP1B enzyme inhibitors and its preparation method and application |
| CN108147951A (en) * | 2018-01-17 | 2018-06-12 | 包骏 | A kind of benzene alkenyl class compound and its preparation method and application |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106946744A (en) * | 2017-03-17 | 2017-07-14 | 上海交通大学 | A kind of new PTP1B enzyme inhibitors and its preparation method and application |
| CN108147951A (en) * | 2018-01-17 | 2018-06-12 | 包骏 | A kind of benzene alkenyl class compound and its preparation method and application |
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