CN115010592B - Preparation method of 4-bromophthalic acid - Google Patents
Preparation method of 4-bromophthalic acid Download PDFInfo
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- CN115010592B CN115010592B CN202210846906.XA CN202210846906A CN115010592B CN 115010592 B CN115010592 B CN 115010592B CN 202210846906 A CN202210846906 A CN 202210846906A CN 115010592 B CN115010592 B CN 115010592B
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- C07—ORGANIC CHEMISTRY
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- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/093—Preparation of halogenated hydrocarbons by replacement by halogens
- C07C17/10—Preparation of halogenated hydrocarbons by replacement by halogens of hydrogen atoms
- C07C17/12—Preparation of halogenated hydrocarbons by replacement by halogens of hydrogen atoms in the ring of aromatic compounds
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
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- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
- C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
- C07C51/255—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting
- C07C51/265—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting having alkyl side chains which are oxidised to carboxyl groups
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- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
- C07C51/44—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation by distillation
- C07C51/46—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation by distillation by azeotropic distillation
Abstract
The invention discloses a preparation method of 4-bromophthalic acid, which comprises the following steps: preparing 4-bromo-o-xylene from o-xylene; mixing 4-bromo-o-xylene with cobalt acetate, manganese acetate, tetrabromoethane and a solvent, heating to 150-220 ℃ in an autoclave, introducing air for 0.5-1.5 h, introducing oxygen for 2-8 h, maintaining the pressure at 1.2-1.5 Mpa, and carrying out liquid-phase oxidation reaction to obtain a reaction solution containing 4-bromophthalic acid; and then carrying out corresponding post-treatment to obtain the 4-bromophthalic acid. The invention can obtain higher recovery rate of the solvent and recovery rate of the crude product, and realize recovery and reuse of the solvent and the entrainer.
Description
Technical Field
The invention belongs to the technical field of organic chemical synthesis, and relates to a preparation method of 4-bromophthalic acid.
Background
4-bromophthalic acid, 4-Bromophthalic acid, having the formula C 8 H 5 BrO 4 The molecular weight is 245.03, and the structural formula is shown in formula 1. In recent years, with the advancement of aerospace, electronics technology, and the likeWith the rapid development, there is an increasing demand for high performance materials. The aromatic polyimide material has the advantages of good high temperature resistance, acid and alkali resistance, radiation resistance, low dielectric property and the like, and is widely applied to various fields of aerospace, electronic manufacturing, automobile manufacturing and the like. 4-bromophthalic acid is taken as an important polyimide production raw material, and the demand is remarkably increased.
The current preparation method of 4-bromophthalic acid is as follows:
1.Todorovic M,Schwab K D in Fluorescent Isoindole Crosslink (FlICk) Chemistry: A Rapid, user-friendly Stapling reaction, angewandte Chemistry-International Edition,2019, 58 (40): 14120-4, it was reported that a potassium permanganate solution was added dropwise to 4-bromoo-xylene, stirred at room temperature for 12 hours, dissolved by adding KOH, filtered, added EtOH to the filtrate, and allowed to stand at 0℃to give 48% yield of 4-bromophthalic acid. The method has low yield and poor economic benefit, and is environment-friendly due to the use of a large amount of potassium permanganate solution.
2. Wei Guobing, hu Jijun et al, in the synthesis of 5-bromobenzofuranone, a fine chemical intermediate, 2007, no.167 (02): 44-45. A method for the catalytic oxidation of 4-bromo-o-xylene to 5-bromobenzofuranone is reported, using pure oxygen as the oxidant, cobalt acetate, manganese acetate as the catalyst, and sodium bromide as the initiator. The mole ratio of the 4-bromine o-xylene, the cobalt acetate, the manganese acetate and the sodium bromide is 2:1:1:1 (namely, the mass ratio of 4-bromo-o-xylene to cobalt acetate to manganese acetate to sodium bromide is 1:48%:48%: 28%), the temperature is 110 ℃, the reaction is carried out for 10 hours, and the yield is 69.1%. The method avoids using a strong oxidant, but has the disadvantages of large catalyst usage amount, long reaction time and low yield, and is not suitable for industrial production. Pure oxygen is used as an oxidant, the reaction speed is high, but the temperature rise is large, and the safety is low. Meanwhile, if the dosage of the composite catalyst consisting of cobalt acetate, manganese acetate and sodium bromide is reduced, the yield is obviously reduced.
3. The chinese patent application No. CN201510896105.4 discloses a method for synthesizing 4-bromophthalic anhydride, i.e. sodium hydroxide is dissolved in water, phthalic acid is added, phase transfer catalyst is stirred uniformly, heating is carried out, 20% fuming sulfuric acid is added for acidification, sodium bisulfate aqueous solution is added for removing excessive bromine after cooling, organic solvent is added for extraction, organic solvent is removed by distillation, and then heating is carried out to obtain crude 4-bromophthalic acid. The method has complex steps, uses a large amount of fuming sulfuric acid and bromine, and is not friendly to the environment.
4. The Chinese patent application No. CN201410244731.0 discloses a synthesis method of 4-bromophthalic acid, which comprises the steps of taking phthalic anhydride, sodium hydroxide and sodium bromide as raw materials, uniformly mixing the phthalic anhydride and the sodium hydroxide, adding sodium hypochlorite aqueous solution under ultrasonic conditions for reaction, and simultaneously controlling the pH value of the reaction solution to obtain the target product 4-bromophthalic acid. However, it has been reported that the direct bromination of phthalic acid gives a mixture of 3-bromophthalic acid, 4-bromophthalic acid and dibromophthalic acid. Although dibromophthalic acid can be removed by post-treatment, 3-bromophthalic acid, 4-bromophthalic acid are difficult to separate by distillation means due to the close boiling point, and the production amounts are substantially the same. This results in difficulty in improving the yield and purity of the product.
Disclosure of Invention
The invention aims to solve the technical problem of providing a preparation method of 4-bromophthalic acid, which is simple, low in cost, high in yield and good in safety.
In order to solve the technical problems, the invention provides a preparation method of 4-bromophthalic acid, which comprises the following steps:
1) Preparing 4-bromo-o-xylene from o-xylene;
2) Mixing 4-bromo-o-xylene with cobalt acetate, manganese acetate, tetrabromoethane and a solvent, heating to 150-220 ℃ in an autoclave, introducing air for 0.5-1.5 h, introducing oxygen for 2-8 h, maintaining the pressure at 1.2-1.5 Mpa, and carrying out liquid-phase oxidation reaction to obtain a reaction solution containing 4-bromophthalic acid;
cobalt acetate is 1-10wt% (preferably 4-8wt%) of 4-bromophthalic acid, and manganese acetate is 1-10wt% (preferably 2-4wt%) of 4-bromophthalic acid; tetrabromoethane is 1 to 10wt% (preferably 5%) of 4-bromophthalic acid;
description: cobalt acetate and manganese acetate are used as catalysts, and tetrabromoethane is used as an initiator.
As an improvement of the preparation method of the 4-bromophthalic acid, the method further comprises the following step 3):
3) Adding an entrainer into a reaction solution containing 4-bromophthalic acid for azeotropic distillation to remove a solvent, performing solid-liquid separation to remove the liquid, adding a 3wt% NaOH solution, heating at 60-100 ℃ for 1-5 h, filtering, adding hydrochloric acid into the obtained filtrate until no solid (white solid) is separated out, filtering, and recrystallizing a filter cake to obtain 4-bromophthalic acid.
The azeotropic distillation in the step, the distilled entrainer (n-heptane) returns to the reaction system through a water separator for continuous use, the distilled acetic acid leaves the system to be recovered, and the recovered acetic acid can be continuously used in the step 2); stopping azeotropic distillation when no acetic acid is carried out in the system;
the obtained product is subjected to solid-liquid separation, the separated liquid is n-heptane, 3wt% NaOH solution is added into the residue for heating, and filtration is carried out to obtain a filter cake (as a mixture of recycled cobalt manganese sodium salt catalyst) and filtrate respectively. Hydrochloric acid was added to the filtrate until no white solid precipitated, and filtration was performed. And recrystallizing the filter cake to obtain 4-bromophthalic acid.
As a further improvement of the process for producing 4-bromophthalic acid of the present invention: when the amount of 4-bromoo-xylene in step 2) is 0.05mol, the amount of 3wt% NaOH solution in step 3) is 50 to 100ml.
As a further improvement of the process for producing 4-bromophthalic acid of the present invention, the step 1) is:
adding o-xylene, iron powder and iodine particles into a container, adding (dropwise adding) liquid bromine, stirring for 4-8 h at 0-5 ℃, and standing for 10-15 h at room temperature;
iron powder: ortho-xylene=0.5 to 5wt% (preferably 1% to 2%), iodine granules: ortho-xylene=0.5 to 5wt% (preferably 2% to 3%), liquid bromine: ortho-xylene = 1:1 to 3 (preferably 1:1.5);
the reaction product was washed with 3wt% NaOH solution (twice), and the obtained organic phase was separated and distilled under reduced pressure to obtain 4-bromo-o-xylene.
As a further improvement of the process for producing 4-bromophthalic acid of the present invention: the solvent in the step 2) is acetic acid (acetic acid).
As a further improvement of the process for producing 4-bromophthalic acid of the present invention, the liquid-phase oxidation reaction in the step 2) is: firstly, air is introduced for 1+/-0.1 h, and then oxygen is introduced for 7+/-1 h to maintain the pressure of 1.3+/-0.1 MPa.
As a further improvement of the process for producing 4-bromophthalic acid of the present invention:
in the step 3): the entrainer used for azeotropic distillation was n-heptane.
In the step 3): the solvent used for recrystallization is acetic acid and water according to 1:1 to 2 mass ratio.
The reaction equation for synthesizing 4-bromophthalic acid is as follows:
current oxidation generally uses pure oxygen or air as the oxidant. If air is used as an oxidant, the temperature rise is small, but the selectivity of the reaction is low, byproducts are more, and the reaction process is slow. If pure oxygen is used as an oxidant, the temperature rise in the initial process of the reaction is too severe. The initial oxidation reaction is severe, a large amount of heat is released, obvious temperature rise is caused, and if oxygen is used as an oxidant at the moment, side reaction is aggravated, and the selectivity of a main product is reduced. Therefore, the invention adopts air as the oxidant, which has the advantages of reducing side reactions caused by severe reaction/temperature rise in the initial reaction, and then changing oxygen into the oxidant after the oxidation reaction is carried out for a period of time, and has the advantages of promoting the conversion of raw materials, improving the reaction rate and promoting the main reaction. Therefore, the variable composition gaseous oxidant of the present invention is preferably introduced with air for 1 hour and then oxygen for 7 hours.
The invention discloses a process for preparing 4-bromophthalic acid, which comprises the steps of brominating o-xylene, and then carrying out liquid-phase oxidation on 4-bromo-o-xylene. Compared with the prior art, the method has the advantages of low-cost and easily-obtained raw materials, simplified steps, greatly reduced emission of three wastes by liquid phase oxidation, reduced production cost, reduced environmental protection pressure, high product purity, low impurity content and high yield. Meanwhile, compared with pure oxygen as an oxidant, the invention uses the composition-variable gas as the oxidant, the temperature rise in the reaction process is small (the maximum temperature rise is only 5-8 ℃ after air and oxygen in the invention, and the maximum temperature rise is 15-20 ℃ after pure oxygen reaction), and the safety is good. The product yield of the invention reaches more than 80 percent, the purity reaches more than 98.5 percent, and the quality of the product is effectively improved.
In summary, the preparation method of 4-bromophthalic acid has the following technical advantages:
1. the method uses cheap and easily available o-xylene as the raw material, reduces the cost of the raw material, has high selectivity of brominated products and few byproducts, and reduces the separation cost.
2. The method uses the composition-variable gas (firstly air and then oxygen) as an oxidant, and synthesizes 4-bromophthalic acid by liquid phase catalytic oxidation of 4-bromo-o-xylene, so that the method has the advantages of thorough reaction, less side reaction, high product yield and environmental friendliness.
3. Tetrabromoethane is set as an initiator, so that the dosage of the catalyst is greatly reduced.
4. N-heptane is selected as an entrainer, an azeotrope can be formed with the solvent (acetic acid) used in the step 2) under normal pressure, the mixture is carried out of the system through distillation, phase separation is carried out after condensation, the n-heptane is recycled in the system, and the acetic acid is recovered after leaving the system. The process can obtain high solvent recovery rate and crude product recovery rate, and realize recovery and reuse of the solvent and the entrainer.
Detailed Description
The invention will be further described with reference to the following specific examples, but the scope of the invention is not limited thereto:
in the present invention, the particle size of the iron powder is about 100-150 μm, and the particle size of the iodine particles is about 15-30mm.
Example 1, a process for the preparation of 4-bromophthalic acid, the following steps were carried out in sequence:
1) 33.0g (0.30 mol) of o-xylene, 0.33g of iron powder and 0.66g of iodine granules were charged into a three-necked flask. 24.0g (0.20 mol) of bromine was added dropwise with stirring at 0 ℃. After the completion of the dropwise addition of the liquid bromine (the dropwise addition time is about 30 minutes), the mixture was stirred at 0℃for 5 hours and allowed to stand at room temperature for 14 hours. The organic phase (in the lower layer) was then separated by washing twice with 3wt% NaOH solution (50 ml. Times.2). The organic phases obtained from the two washes were combined and distilled under reduced pressure at-97 kPa to remove o-xylene and the 114-118 ℃ fractions were collected to give 0.15mol of 4-bromo-o-xylene with a yield of 75.5%.
2) 9.25g (0.05 mol) of 4-bromoo-xylene, 0.37g (0.002 mol) of cobalt acetate, 0.19g (0.001 mol) of manganese acetate, 0.46g of tetrabromoethane and 30g of acetic acid are weighed and placed in an autoclave, and under the conditions of 200 ℃, 1000rpm and 1.3MPa, 1h of air (the pressure of the autoclave is 1.3 MPa) is firstly introduced, and then 7h of oxygen is introduced to keep the pressure of 1.3MPa, namely, the total reaction is carried out for 8h.
3) After the reaction is finished, 50ml of kettle liquid and n-heptane are mixed and then subjected to azeotropic distillation (the temperature is about 90 ℃) in a three-neck flask, the distilled n-heptane returns to the reaction system through a water separator for continuous use, distilled acetic acid leaves the system and is recovered, and the recovered acetic acid can be continuously used for the oxidation reaction in the step 2); when no acetic acid is carried out in the system, the azeotropic distillation is stopped.
The obtained product was subjected to solid-liquid separation, the separated liquid was n-heptane, 100ml of 3wt% naoh solution was added to the residue in the three-necked flask, and heated at 80 ℃ for 2 hours, and filtered to obtain a cake (as a mixture of recycled cobalt manganese sodium salt catalyst) and a filtrate, respectively. Hydrochloric acid was added to the filtrate until no white solid had precipitated (the amount of hydrochloric acid was about 50 ml), and filtration was performed. The filter cake was recrystallized from 50wt% acetic acid (100 ml) heated to 80℃to give 9.87g (0.04 mol) of 4-bromophthalic acid in 80.6% yield and 99% purity.
Example 2, a process for the preparation of 4-bromophthalic acid, the following steps were carried out in sequence:
1) 33.0g of o-xylene, 0.66g of iron powder and 0.66g of iodine granules were charged into a three-necked flask. 24.0g of liquid bromine is dripped under the stirring condition at 0 ℃. After the completion of the dropwise addition, stirring was carried out at 0℃for 5 hours, and the mixture was allowed to stand at room temperature for 14 hours. The organic phase was then separated by washing twice with 3wt% NaOH solution. The organic phases obtained from the two washes were combined and distilled under reduced pressure at-97 kPa to remove o-xylene, and the fractions at 114-118℃were collected to give 0.155mol of 4-bromoo-xylene in 77.5% yield.
2) 9.25g of 4-bromo-o-xylene, 0.37g of cobalt acetate, 0.37g of manganese acetate, 0.46g of tetrabromoethane and 30g of acetic acid are weighed and placed in an autoclave, and under the conditions of 200 ℃, 1000rpm and 1.3MPa, 1h of air is firstly introduced, and then 7h of oxygen is introduced to keep the pressure at 1.3MPa, namely, the reaction is carried out for 8h.
3) Equivalent to step 3) of example 1);
9.36g (0.038 mol) of 4-bromophthalic acid was obtained in a yield of 76.4%.
Example 3, a process for the preparation of 4-bromophthalic acid, the following steps were carried out in sequence:
1) 33.0g of o-xylene, 0.66g of iron powder and 0.99g of iodine granules were charged into a three-necked flask. 24.0g of liquid bromine is dripped under the stirring condition at 0 ℃. After the completion of the dropwise addition, stirring was carried out at 0℃for 5 hours, and the mixture was allowed to stand at room temperature for 14 hours. The organic phase was then separated by washing twice with 3wt% NaOH solution. The organic phases obtained from the two washes were combined and distilled under reduced pressure at-97 kPa to remove o-xylene, and the fractions at 114-118℃were collected to give 0.155mol of 4-bromoo-xylene in 77.5% yield.
2) 9.25g of 4-bromo-o-xylene, 0.74g of cobalt acetate, 0.37g of manganese acetate, 0.46g of tetrabromoethane and 30g of acetic acid are weighed and placed in an autoclave, and under the conditions of 200 ℃, 1000rpm and 1.3MPa, 1h of air is firstly introduced, and then 7h of oxygen is introduced to keep the pressure at 1.3MPa, namely, the reaction is carried out for 8h.
3) Equivalent to step 3) of example 1);
9.86g (0.04 mol) of 4-bromophthalic acid was obtained in a yield of 80.5%.
Example 4, a process for the preparation of 4-bromophthalic acid, the following steps were carried out in sequence:
1) 16.5g of o-xylene mother liquor distilled off by distillation under reduced pressure and 16.5g of fresh o-xylene in the same manner as in step 1) of example 1, 0.33g of iron powder and 0.66g of iodine granules were charged into a three-necked flask. 23.97g of bromine was added dropwise with stirring at 0 ℃. After the completion of the dropwise addition, stirring was carried out at 0℃for 5 hours, and the mixture was allowed to stand at room temperature for 14 hours. The organic phase was then separated by washing twice with 3wt% NaOH solution. The organic phases obtained from the two washes were combined and distilled under reduced pressure at-97 kPa to remove o-xylene and the 114-118 ℃ fractions were collected to give 0.17mol of 4-bromo-o-xylene with a yield of 85.7%.
2) 9.25g of the above 4-bromoo-xylene, 0.37g of cobalt acetate, 0.19g of manganese acetate, 0.46g of tetrabromoethane and 30g of acetic acid were weighed and placed in an autoclave. Under the conditions of 200 ℃, 1000rpm and 1.3MPa, air is introduced for 1h, and then oxygen is introduced for 7h to keep the pressure of 1.3MPa, namely, the reaction is carried out for 8h.
3) Equivalent to step 3) of example 1);
9.87g (0.04 mol) of 4-bromophthalic acid was obtained in a yield of 80.6%.
Example 5, a process for the preparation of 4-bromophthalic acid, the following steps were carried out in sequence:
1) 16.5g of o-xylene mother liquor distilled off by distillation under reduced pressure and 16.5g of fresh o-xylene in the same manner as in step 1) of example 1, 0.33g of iron powder and 0.66g of iodine granules were charged into a three-necked flask. 23.97g of bromine was added dropwise with stirring at 0 ℃. After the completion of the dropwise addition, stirring was carried out at 0℃for 5 hours, and the mixture was allowed to stand at room temperature for 14 hours. The organic phase was then separated by washing twice with 3wt% NaOH solution. The organic phases obtained from the two washes were combined and distilled under reduced pressure at-97 kPa to remove o-xylene and the 114-118 ℃ fractions were collected to give 0.17mol of 4-bromo-o-xylene with a yield of 85.7%.
2) 9.25g of the above-mentioned 4-bromoo-xylene, 0.19g of cobalt acetate, 0.10g of manganese acetate, 0.46g of tetrabromoethane and 30g of acetic acid were weighed, and 0.29g of the mixture of the cobalt manganese sodium salt catalyst recovered in example 1 was added thereto and placed in an autoclave. Under the conditions of 200 ℃, 1000rpm and 1.3MPa, air is introduced for 1h, and then oxygen is introduced for 7h to keep the pressure of 1.3MPa, namely, the reaction is carried out for 8h.
3) Equivalent to step 3) of example 1);
6.38g (0.026 mol) of 4-bromophthalic acid was obtained in a yield of 52.1%.
Comparative example 1, changing the mass fraction of iron powder in step 1) of example 1 to 0.1%,10%,15% relative to ortho-xylene from 1%; the remaining conditions are equivalent to step 1) of example 1. The yields of 4-bromo-ortho-xylene obtained in step 1) are shown in Table 1 below.
TABLE 1
Comparative example 2, the mass fraction of iodine granules in step 1) of example 1 was changed from 2% to 0.1%,10% and 15% with respect to o-xylene; the remainder being identical to step 1) of example 1. The yields of 4-bromoo-xylene obtained in step 1) are shown in Table 2 below.
TABLE 2
Comparative example 3, wherein the mass fraction of cobalt acetate relative to 4-bromo-o-xylene in step 2) of example 1 is changed from 4% to 20%,0.5% and 0.1%; the remainder are identical to example 1. The final yields of the 4-bromophthalic acid obtained are shown in Table 3 below.
TABLE 3 Table 3
Comparative example 4, the mass fraction of manganese acetate relative to 4-bromo-o-xylene in step 2) of example 1 was changed from 2% to 20%,0.5%,0.1%; the remainder are identical to example 1. The final yields of the 4-bromophthalic acid obtained are shown in Table 4 below.
TABLE 4 Table 4
Comparative example 5-1, "1 h of air was introduced first, and then 7h of oxygen maintaining pressure 1.3Mpa" was changed to "8 h of oxygen maintaining pressure 1.3Mpa" in step 2) of example 1, and the rest was identical to example 1. The yield of the finally obtained 4-bromophthalic acid was 50.8%.
Comparative example 5-2, "1 h of air was introduced first, then 7h of oxygen maintaining pressure 1.3Mpa" was changed to "2 h of air was introduced first, then 6h of oxygen maintaining pressure 1.3Mpa" in step 2) of example 1, and the rest was the same as example 1. The yield of the finally obtained 4-bromophthalic acid was 42.5%.
Comparative example 6 the entrainer used in the azeotropic distillation of step 3) of example 1 was changed from n-heptane to cyclohexane, n-octane, the remainder being identical to example 1. The final yields of 4-bromophthalic acid obtained are shown in Table 5 below.
TABLE 5
Comparative example 7 the azeotropic distillation in step 3) of example 1 was changed to direct distillation, the remainder being identical to example 1. The yield of the finally obtained 4-bromophthalic acid was 50.2%, and the recovery rate of acetic acid was 32.4%.
Finally, it should also be noted that the above list is merely a few specific embodiments of the present invention. Obviously, the invention is not limited to the above embodiments, but many variations are possible. All modifications directly derived or suggested to one skilled in the art from the present disclosure should be considered as being within the scope of the present invention.
Claims (6)
- The preparation method of the 4-bromophthalic acid is characterized by comprising the following steps:1) Preparing 4-bromo-o-xylene from o-xylene;2) Mixing 4-bromo-o-xylene with cobalt acetate, manganese acetate, tetrabromoethane and a solvent, heating to 150-220 ℃ in an autoclave, introducing air for 0.5-1.5 h, introducing oxygen for 2-8 h, maintaining the pressure at 1.2-1.5 mpa, and performing liquid-phase oxidation reaction to obtain a reaction solution containing 4-bromophthalic acid;the cobalt acetate is 1-10wt% of 4-bromophthalic acid, and the manganese acetate is 1-10wt% of 4-bromophthalic acid; the tetrabromoethane is 1-10wt% of 4-bromophthalic acid;3) And adding an entrainer into the reaction liquid containing the 4-bromophthalic acid for azeotropic distillation to remove the solvent, then carrying out solid-liquid separation to remove the liquid, adding a 3wt% NaOH solution, heating at 60-100 ℃ for 1-5 h, filtering, adding hydrochloric acid into the obtained filtrate until no solid is separated out, filtering, and recrystallizing a filter cake to obtain the 4-bromophthalic acid.
- 2. The process for producing 4-bromophthalic acid according to claim 1, characterized in that: when the 4-bromo-o-xylene in the step 2) is 0.05mol, the 3wt% NaOH solution in the step 3) is used in an amount of 50-100 ml.
- 3. The process for the preparation of 4-bromophthalic acid according to claim 1 or 2, characterized in that said step 1) is:adding o-xylene, iron powder and iodine particles into a container, adding liquid bromine, stirring for 4-8 hours at 0-5 ℃, and standing for 10-15 hours at room temperature;iron powder: 0.5-5wt% of o-xylene and iodine particles: 0.5-5wt% of o-xylene, and liquid bromine: ortho-xylene is 1:1 to 3 molar ratio;the reaction product was washed with 3wt% NaOH solution, and the separated organic phase was distilled under reduced pressure to obtain 4-bromo-o-xylene.
- 4. A process for the preparation of 4-bromophthalic acid according to claim 3, characterized in that: the solvent in the step 2) is acetic acid.
- 5. The process for producing 4-bromophthalic acid according to claim 4, wherein:the liquid phase oxidation reaction in the step 2) is as follows: firstly, air is introduced for 1+/-0.1 h, and then oxygen is introduced for 7+/-1 h to maintain the pressure of 1.3+/-0.1 MPa.
- 6. The process for producing 4-bromophthalic acid according to claim 5, characterized in that:in the step 3): the entrainer used in the azeotropic distillation is n-heptane;in the step 3): the solvent used for recrystallization is acetic acid and water according to 1: 1-2 mass ratio of the mixed solution.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3721708A (en) * | 1968-12-14 | 1973-03-20 | Huels Chemische Werke Ag | Process for the preparation of o-phthalic acid |
| TW201439050A (en) * | 2013-04-02 | 2014-10-16 | Nat Univ Kaohsiung | Synthesis method of oligo-anthracene and oligo-anthracene thereof |
| CN107698436A (en) * | 2016-08-09 | 2018-02-16 | 朱翠英 | A kind of method for preparing the more formic acid analog derivatives of aromatic hydrocarbons |
| CN113735806A (en) * | 2021-08-03 | 2021-12-03 | 哈尔滨工业大学（威海） | Method for preparing chlorophthalic anhydride by solvent-free liquid phase catalytic oxidation |
| CN114369099A (en) * | 2021-12-21 | 2022-04-19 | 中海油天津化工研究设计院有限公司 | Method for preparing pyromellitic dianhydride by liquid-phase oxidation |
-
2022
- 2022-07-19 CN CN202210846906.XA patent/CN115010592B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3721708A (en) * | 1968-12-14 | 1973-03-20 | Huels Chemische Werke Ag | Process for the preparation of o-phthalic acid |
| TW201439050A (en) * | 2013-04-02 | 2014-10-16 | Nat Univ Kaohsiung | Synthesis method of oligo-anthracene and oligo-anthracene thereof |
| CN107698436A (en) * | 2016-08-09 | 2018-02-16 | 朱翠英 | A kind of method for preparing the more formic acid analog derivatives of aromatic hydrocarbons |
| CN113735806A (en) * | 2021-08-03 | 2021-12-03 | 哈尔滨工业大学（威海） | Method for preparing chlorophthalic anhydride by solvent-free liquid phase catalytic oxidation |
| CN114369099A (en) * | 2021-12-21 | 2022-04-19 | 中海油天津化工研究设计院有限公司 | Method for preparing pyromellitic dianhydride by liquid-phase oxidation |
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