A method for producing a photoinitiator UV-185
The photoinitiator UV-185 was prepared by condensing isobutyric acid with tert-butylbenzoic acid in the presence of Mn2+ salt and K2CO3 catalyst, which solved the problem of high temperature and high energy consumption and realized an environmentally friendly production process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NINGXIA WOKAILONG NEW MATERIAL CO LTD
- Filing Date
- 2024-02-07
- Publication Date
- 2026-07-03
AI Technical Summary
The existing production process for the photoinitiator UV-185 involves high reaction temperatures, high energy consumption, and the use of large quantities of hazardous chemicals, generating a large amount of waste.
Isobutyric acid and tert-butylbenzoic acid were used as raw materials and condensed at 170℃-310℃ under the combined action of Mn2+ salt and K2CO3 catalyst to generate 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone. Then, chlorination and alkaline hydrolysis were carried out to prepare the photoinitiator UV-185.
The reaction temperature was lowered to 170℃-310℃, which reduced the use of hazardous chemicals and the amount of waste generated, thus achieving an environmentally friendly production process.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of fine chemical technology, and in particular relates to a method for producing a photoinitiator UV-185. Background Technology
[0002] Photoinitiator UV-185 (2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone, CAS No. 68400-54-4, molecular formula C 14 H 20 O2 is an organic compound that is often used to synthesize drugs and bioactive compounds. In the field of drug development, it is often used to synthesize anticancer drugs, antiviral drugs, and antibacterial drugs. It can also be used to synthesize dyes, fragrances, and cosmetics.
[0003] Using isobutyric acid (CAS No. 79-31-2) as a raw material, 2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone is prepared sequentially through acylation, Friedel-Crafts reaction, chlorination, and alkaline hydrolysis. This is a major production method for the photoinitiator UV-185. For example, Chinese invention patent CN201810727566.2 describes a similar process for producing the photoinitiator UV-185. However, the above process not only requires a large amount of hazardous chemicals, such as phosphorus trichloride, aluminum trichloride, and chlorine, but also generates a large amount of waste, such as high-phosphorus wastewater, molten aluminum from Friedel-Crafts hydrolysis, hydrogen chloride gas, and hydrochloric acid wastewater, which is detrimental to environmental friendliness.
[0004] To overcome the above problems, Chinese invention patent CN202210420326.4 discloses a method for producing photoinitiator 185, using isobutyric acid and tert-butylbenzoic acid as raw materials, in Mn 2+ Under the action of one or more catalysts in the salt, 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone is generated. The intermediate product 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone is distilled off through condensation, separation, and distillation, ultimately yielding 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone to synthesize photoinitiator 185. While the above process reduces the use of hazardous chemicals and lowers the amount of waste generated, the optimal reaction temperature is 280℃-320℃, which is relatively high, resulting in high energy consumption. Summary of the Invention
[0005] Based on this, the present invention provides a method for producing the photoinitiator UV-185 to solve the technical problems of high reaction temperature and high energy consumption in the reaction process of the prior art.
[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:
[0007] A method for producing a photoinitiator UV-185 includes:
[0008] S10. Mix isobutyric acid and tert-butylbenzoic acid to prepare raw material mixture A, wherein the molar ratio of isobutyric acid to tert-butylbenzoic acid is 1:(0.6-1.0);
[0009] S20. The raw material mixture A comes into contact with the catalyst and undergoes a condensation reaction at the first reaction temperature to produce 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone; wherein the catalyst is Mn. 2+ A mixture of salt and K2CO3, Mn 2+ The molar ratio of salt to potassium carbonate is 1:(0.5-1.0), and the first reaction temperature is 170℃-310℃;
[0010] S30. Synthesize (2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone) from 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone.
[0011] Preferably, in step S20, the step of "the raw material mixture A comes into contact with the catalyst, and at the first reaction temperature, a condensation reaction occurs to generate 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone" includes the following steps:
[0012] S21. Catalyst activation stage: Heat the raw material mixture A to the activation temperature, add the catalyst, mix thoroughly, and keep warm for the first time;
[0013] S22. Condensation reaction stage: After the heat preservation is completed, the raw material mixture A is added dropwise at the first reaction temperature to carry out the condensation reaction; the gas phase fraction is collected by condensation to obtain crude product B;
[0014] S23. Separation stage: Separate unreacted raw materials isobutyric acid and tert-butylbenzoic acid from crude product B to prepare 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone.
[0015] Preferably, the first reaction temperature is 220℃-260℃.
[0016] Preferably, in step S21, the activation temperature is 200℃-400℃.
[0017] Preferably, in step S22, after the heat preservation is completed, at the first reaction temperature, the raw material mixture A is added dropwise at a dropping rate of 40g / h-75g / h per kilogram of catalyst to carry out the condensation reaction.
[0018] Preferably, in step S21, the mass ratio of catalyst to raw material mixture A is 1:(1-1.5).
[0019] Preferably, the catalyst Mn 2+ The salt can be one or more of MnO, MnSO4, and MnCO3.
[0020] Preferably, the molar ratio of isobutyric acid to tert-butylbenzoic acid is 1:(0.83-0.90).
[0021] Preferably, in step S30, the "synthesis of 2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone from 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone" includes the following steps: using 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone as a raw material, 2-hydroxy-2-methyl-1-phenyl-1-propanone is prepared through chlorination and alkaline hydrolysis processes.
[0022] Preferably, in step S30, the synthesis of 2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone from 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone includes the following steps:
[0023] S31. Chlorination reaction: At a chlorination reaction temperature of 50℃-80℃, Cl2 is introduced into 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone to carry out the chlorination reaction and obtain chloroketone A;
[0024] S32. Alkaline hydrolysis reaction: Chlorone A is added to liquid alkali and stirred to carry out the alkaline hydrolysis reaction to prepare 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone.
[0025] Compared with the prior art, the present invention has at least the following advantages:
[0026] This invention provides a method for producing the photoinitiator UV-185, using isobutyric acid and tert-butylbenzoic acid as raw materials, in a Mn... 2+In the presence of salt and K₂CO₃, a condensation reaction occurs at a temperature of 170℃-310℃, yielding the intermediate 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone in one step. Then, 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone is chlorinated and subjected to alkaline hydrolysis to prepare (2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone) (i.e., photoinitiator UV-185). The method provided by this invention synthesizes 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone in one step. Compared with the Friedel-Crafts reaction process, it reduces the use of hazardous chemicals and the generation of waste, making it an environmentally friendly production process. Compared with existing technologies, by mixing potassium carbonate into the catalyst, experiments show that the reaction temperature can be reduced to 170℃-310℃, and the optimal reaction temperature can be reduced to 220℃-260℃, a reduction of 30℃-50℃, thus helping to reduce energy consumption. Detailed Implementation
[0027] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this invention can be combined with each other. The technical solutions of this invention will be further described below in conjunction with the embodiments of this invention, and this invention is not limited to the specific implementation methods described below.
[0028] In one embodiment, a method for producing a photoinitiator UV-185 includes:
[0029] S10. Mix isobutyric acid and tert-butylbenzoic acid to prepare raw material mixture A, wherein the molar ratio of isobutyric acid to tert-butylbenzoic acid is 1:(0.6-1.0);
[0030] Preferably, the molar ratio of isobutyric acid to tert-butylbenzoic acid is 1:(0.83-0.90), meaning that isobutyric acid is in excess in the reaction raw material system.
[0031] S20. The raw material mixture A comes into contact with the catalyst and undergoes a condensation reaction at the first reaction temperature to produce 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone; wherein the catalyst is Mn. 2+ A mixture of salt and potassium carbonate, Mn 2+ The molar ratio of salt to K2CO3 is 1:(0.5-1.0), and the first reaction temperature is 170℃-310℃;
[0032] Preferably, the first reaction temperature is 170℃-310℃, and further, the first reaction temperature is 220℃-260℃.
[0033] At temperatures of 170℃-310℃, with Mn 2+Using salt as a catalyst, tert-butylbenzoic acid and isobutyric acid undergo a condensation reaction to produce 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone, along with water and carbon dioxide. At high temperatures, the water and carbon dioxide are expelled from the reaction system in gaseous form, which facilitates the reaction.
[0034] For example, catalyst Mn 2+ The salt can be one or more of MnO, MnSO4, and MnCO3. The catalyst can also be Mn. 2+ A mixture of salt and K2CO3. Preferably, Mn... 2+ Salt can be MnO.
[0035] Specifically, the above process includes the following steps:
[0036] S21. Catalyst activation stage: Heat the raw material mixture A to the activation temperature, add the catalyst, mix thoroughly, and keep warm for the first time.
[0037] In one specific embodiment, the raw material mixture A is first heated to the activation temperature, for example, 200℃-400℃, and the gas phase is condensed and collected to establish total reflux. After heating to the target temperature, the catalyst Mn is added. 2+ Salt is preferred, and the amount of catalyst added is 1-1.5 times the mass of the raw material mixture A. Thorough stirring is performed to ensure the catalyst Mn... 2+ Mix the salt thoroughly with raw material mixture A and keep warm for 6-24 hours.
[0038] S22. Condensation reaction stage: After the heat preservation is completed, the raw material mixture A is added dropwise at the first reaction temperature to carry out the condensation reaction; the gas phase fraction is collected by condensation to obtain crude product B.
[0039] To catalyst Mn 2+After the salt-heated activation process, raw material mixture A is added dropwise to the reaction system to initiate a condensation reaction. The vapor fraction is collected by condensation; part of it is returned to the reaction system as reflux liquid, and the remainder is collected as a crude product containing 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone. Preferably, the first reaction temperature is 170℃-320℃. Raw material mixture A should be slowly added dropwise to the reaction system; preferably, it is added at a dropping rate of 40 g / h-75 g / h per kilogram of catalyst to initiate the condensation reaction. It is worth noting that the statement "add raw material mixture A at a dropping rate of 40g / h-75g / h per kilogram of catalyst" should be understood as follows: if the catalyst content in the system is 1kg, the dropping rate of raw material mixture A is 40g / h-75g / h; if the catalyst content in the system is 2kg, the dropping rate of raw material mixture A is 80g / h-150g / h; if the catalyst content in the system is 1000kg, the dropping rate of raw material mixture A is 40kg / h-75kg / h, and so on.
[0040] S23. Separation stage: Separate unreacted raw materials isobutyric acid, tert-butylbenzoic acid, and 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone from crude product B.
[0041] For example, distillation can be used to separate the raw material isobutyric acid and the intermediate product 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone from crude product B.
[0042] S30. Synthesize (2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone) from 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone.
[0043] 2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone can be synthesized from 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone using various methods. For example, as proposed in Chinese invention patent CN201810727566.2, 2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone can be prepared by a one-pot chlorination and alkaline hydrolysis reaction using 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone as a raw material, carbon tetrachloride and sodium hydroxide as reagents, and tetrabutylammonium bromide as a phase transfer catalyst.
[0044] The following specific experimental examples further illustrate the technical solution and technical effects of the present invention.
[0045] Comparative Example 1
[0046] Isobutyric acid and tert-butylbenzoic acid were mixed at a mass ratio of 1:0.83. 2 kg of catalyst MnO was added to an experimental batch reactor, and the mixture was stirred and heated for activation. The temperature was slowly increased, and at temperatures of 170℃, 220℃, 260℃, 280℃, 310℃, and 400℃, a dripping rate of 100 g / h was initiated. After the dripping was complete, the reaction was allowed to proceed for 2 hours. Then, the prepared raw material mixture was added dropwise to the experimental batch reactor to initiate a condensation reaction. The fraction produced by the condensation reaction was collected by condensing the feed through a condenser. The collected condensate was then distilled, and excess isobutyric acid was recovered and reused in a mixed acid preparation to obtain the intermediate 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone. The obtained 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone was subjected to chlorination, alkaline hydrolysis, and distillation to obtain 2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone as a photoinitiator.
[0047] The yield of tert-butylbenzoic acid was determined and calculated, as shown in Table 1.
[0048] Example 1
[0049] Similar to Comparative Example 1, but the catalyst in Comparative Example 1 was replaced with a mixture of catalysts MnO and K2CO3 (molar ratio of 1:1).
[0050] The yield of the obtained products was detected and calculated, as shown in Table 1.
[0051] Table 1: Product Yield
[0052]
[0053] As shown in Table 1, when the catalyst is MnO, the yield of tert-butylbenzoic acid reaches 94.6% when the reaction temperature reaches 280℃; when the catalyst is a mixture of MnO and K2CO3, the yield of tert-butylbenzoic acid reaches 95.3% when the reaction temperature reaches 220℃.
[0054] Example 2
[0055] Same as in Example 1, except that the catalyst was replaced with a mixture of MnCO3 and K2CO3 (molar ratio of 1:1), and the reaction temperature was 260°C.
[0056] The yield of tert-butylbenzoic acid was determined and calculated, as shown in Table 2.
[0057] Example 3
[0058] Similar to Example 2, except that the catalyst in Example 2 was replaced with a mixture of MnO and K2CO3, with a molar ratio of MnO to K2CO3 of 1:0.5.
[0059] The yield of tert-butylbenzoic acid was determined and calculated, as shown in Table 2.
[0060] Example 4
[0061] Same as Example 2, except that the molar ratio of the mixture of MnCO3 and K2CO3 in Example 2 is changed to 1:0.5.
[0062] The yield of tert-butylbenzoic acid was determined and calculated, as shown in Table 2.
[0063] Example 5
[0064] Similar to Example 2, except that the catalyst in Example 2 is replaced with a mixture of MnO, K2CO3 and MnCO3, with a molar ratio of 1:1:1.
[0065] The yield of tert-butylbenzoic acid was determined and calculated, as shown in Table 2.
[0066] Table 2: Product Yield
[0067]
[0068] As shown in Table 2, the yield of tert-butylbenzoic acid increases after the addition of K2CO3 to the catalyst. When the catalyst is a mixture of MnO, K2CO3 and MnCO3, the yield of tert-butylbenzoic acid reaches 95.8%.
[0069] Example 6
[0070] Isobutyric acid and tert-butylbenzoic acid were mixed in mass ratios of 1:0.6, 1:0.83, 1:0.9, and 1:1.0. A mixture of 2 kg of catalysts MnO and K₂CO₃ was added to an experimental batch reactor and activated by stirring and heating. The temperature was slowly increased, and when it reached 260°C, a dripping rate of 100 g / h was initiated. After the dripping was complete, the reaction was carried out for 2 hours. Then, the prepared raw material mixture was added dropwise to the experimental batch reactor for a condensation reaction. The fraction produced by the condensation reaction was collected by condensing the feed through a condenser. The collected condensate was then distilled, and excess isobutyric acid was recovered and reused in a mixed acid preparation to obtain the intermediate 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone. The obtained 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone was subjected to chlorination, alkaline hydrolysis, and distillation to obtain 2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone as a photoinitiator.
[0071] The yield of tert-butylbenzoic acid was determined and calculated, as shown in Table 3.
[0072] Table 3: Product Yield
[0073]
[0074] As can be seen from Table 3, when the catalyst is a mixture of MnO and K2CO3, the mass ratio of isobutyric acid to tert-butylbenzoic acid is 1:0.6, and the reaction temperature is 260℃, the yield of the product is the highest, reaching 95.4%.
[0075] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.
Claims
1. A method for producing a photoinitiator UV-185, characterized by: include S10. Mix isobutyric acid and tert-butylbenzoic acid to prepare raw material mixture A, wherein the molar ratio of isobutyric acid to tert-butylbenzoic acid is 1:(0.6-1.0); S20. The raw material mixture A comes into contact with the catalyst and undergoes a condensation reaction at the first reaction temperature to produce 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone; wherein the catalyst is Mn. 2+ A mixture of salt and K2CO3, Mn 2+ The molar ratio of salt to potassium carbonate is 1:(0.5-1.0), and the first reaction temperature is 170℃-260℃; S30. Synthesize (2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone) from 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone.
2. The method of producing the photoinitiator UV-185 according to claim 1, characterized in that: In step S20, the step of "the raw material mixture A comes into contact with the catalyst and undergoes a condensation reaction at a first reaction temperature to generate 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone" includes the following steps: S21. Catalyst activation stage: Heat the raw material mixture A to the activation temperature, add the catalyst, mix thoroughly, and keep warm for the first time; S22. Condensation reaction stage: After the heat preservation is completed, the raw material mixture A is added dropwise at the first reaction temperature to carry out the condensation reaction; the gas phase fraction is collected by condensation to obtain crude product B; S23. Separation stage: Separate unreacted raw materials isobutyric acid and tert-butylbenzoic acid from crude product B to prepare 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone.
3. The method for producing the photoinitiator UV-185 as described in claim 2, characterized in that: The first reaction temperature is 220℃-260℃.
4. The method of producing the photoinitiator UV-185 according to claim 2, characterized by: In step S21, the activation temperature is 200℃-400℃.
5. The method of producing the photoinitiator UV-185 according to claim 2, characterized by: In step S22, after the heat preservation is completed, at the first reaction temperature, the raw material mixture A is added dropwise at a dropping rate of 40g / h-75g / h per kilogram of catalyst to carry out the condensation reaction.
6. The method of producing the photoinitiator UV-185 according to claim 2, characterized by: In step S21, the mass ratio of catalyst to raw material mixture A is 1:(1-1.5).
7. The method for producing the photoinitiator UV-185 as described in claim 1, characterized in that: Catalyst Mn 2+ The salt is one or more of MnO, MnSO4, MnCO3.
8. The method of producing the photoinitiator UV-185 according to claim 1, characterized by: The molar ratio of isobutyric acid to tert-butylbenzoic acid is 1:(0.83-0.90).
9. The method of producing the photoinitiator UV-185 according to claim 1, characterized in that: In step S30, the "synthesis of 2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone" includes the following steps: using 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone as a raw material, 2-hydroxy-2-methyl-1-phenyl-1-propanone is prepared through chlorination and alkaline hydrolysis.
10. The method of producing the photoinitiator UV-185 according to claim 1, characterized in that: In step S30, the process of "synthesizing (2-hydroxy-2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone) from 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone" includes the following steps: S31. Chlorination reaction: At a chlorination reaction temperature of 50℃-80℃, Cl2 is introduced into 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone to carry out the chlorination reaction and obtain chloroketone A; S32. Alkaline hydrolysis reaction: Chlorone A is added to liquid alkali and stirred to carry out the alkaline hydrolysis reaction to prepare 2-methyl-1-[4-(tert-butyl)phenyl]-1-propanone.