Preparation method of hindered amine light stabilizer UV-371
By carrying out oxidation, reduction, and substitution reactions at room temperature and pressure, the problems of environmental pollution, safety risks, and high costs in the synthesis of hindered amine light stabilizer UV-371 in existing technologies have been solved, and high-yield production has been achieved.
Patent Information
- Application Number
- CN202410602052.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-15
- Publication Date
- 2025-11-18
AI Technical Summary
In the existing technology, the preparation method has problems such as serious environmental pollution, high safety risks, high cost and low yield when synthesizing the hindered amine light stabilizer UV-371.
A novel synthetic route was adopted, including oxidation, reduction and substitution reactions, which were carried out at room temperature and pressure, avoiding high-pressure reactions and contaminated solvents. Inorganic halides were used as byproducts, simplifying the process steps and improving the product yield.
It reduces environmental pollution, lowers equipment investment costs, increases product yield, and achieves a safe and reliable production process.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of light stabilizers, and particularly relates to a preparation method of a hindered amine light stabilizer UV-371. BACKGROUND
[0002] It is known that among various light stabilizers, there is a hindered amine light stabilizer with the structural formula as follows:
[0003]
[0004] The preparation of the above hindered amine light stabilizer is generally through the following synthetic route:
[0005] Route one:
[0006]
[0007]
[0008] Route two:
[0009]
[0010] Route one adds the compound with the structural formula (II) above, a solvent, peroxoacetic acid and a catalyst into a reactor, and reacts for a certain time at 20-70 DEG C to obtain an intermediate (III), then adds the intermediate (III), butyl aldehyde or pentanone, hydrogen peroxide and a catalyst into the reactor, and reacts for 10 h at 15 DEG C and then for 2 h at 38 DEG C to obtain the target product. However, the preparation method disclosed by this route has the following problems: (1) the peroxoacetic acid and pentanone used in the reaction produce a large amount of by-product acetic acid, and the butyl aldehyde produces a large amount of by-product formic acid, which needs to be neutralized by a large amount of alkali, thus generating a large amount of waste, which brings great pollution to the environment; (2) the butyl aldehyde used is partially oxidized into butyric acid during the reaction, has a strong odor and seriously affects the health of the operating personnel; (3) a large amount of waste liquid is produced in the reaction, and the waste liquid contains a large amount of sodium formate and sodium acetate which cannot be recycled, thus seriously polluting the environment; (4) the reaction time is long, the yield is low and the product cost is high.
[0011] Route two is to add the compound with the structural formula (II) described above, a solvent, allyl bromide, and an acid binding agent into a high-pressure reactor, and react at 150 DEG C for several hours to obtain intermediate (IV), then add intermediate (IV), a solvent, an oxidizing agent, and a catalyst into the reactor, and react at -15 DEG C to 0 DEG C for 4 h to obtain intermediate (V), then add intermediate (V), a solvent, and a catalyst into the high-pressure reactor, and react at 70 DEG C for 6 h by passing hydrogen to obtain the target product. However, the preparation method disclosed in this route has the following problems: (1) this synthesis route needs two high-pressure reactions, which has a serious safety risk; (2) in the reaction process from (IV) to (V), there are a large number of side reactions, which greatly reduces the reaction yield. SUMMARY
[0012] The present application aims to at least solve one of the technical problems in the related art. To this end, one object of the present application is to propose a preparation method of hindered amine light stabilizer UV-371. The method is simple to operate, safe and reliable, raw materials are easy to obtain, cost investment is low, environment-friendly, and the product yield is high.
[0013] In one aspect of the present application, the present application proposes a preparation method of hindered amine light stabilizer UV-371. According to the embodiments of the present application, the method comprises:
[0014] (1) the compound represented by formula 1, an oxidizing agent, and a catalyst are subjected to an oxidation reaction to obtain a compound represented by formula 2;
[0015] (2) the compound represented by formula 2 and a reducing agent are subjected to a reduction reaction to obtain a compound represented by formula 3;
[0016] (3) the compound represented by formula 3, a propyl halide, and an acid binding agent are subjected to a substitution reaction to obtain hindered amine light stabilizer UV-371;
[0017]
[0018]
[0019] According to the method for preparing hindered amine light stabilizer UV-371 according to the above embodiments of the present application, first, the compound represented by formula 1, an oxidizing agent, and a catalyst are subjected to an oxidation reaction to obtain a compound represented by formula 2, and the specific reaction equation is as follows:
[0020]
[0021] The compound represented by formula 2 and a reducing agent are subjected to a reduction reaction to obtain a compound represented by formula 3, and the specific reaction equation is as follows:
[0022]
[0023] Finally, the compound shown in Formula 3, a propyl halide and an acid binding agent are subjected to a substitution reaction, thereby obtaining the hindered amine light stabilizer UV-371, and the specific reaction process is as follows:
[0024] In the process, no seriously polluting organic solvents such as butyraldehyde are used, the toxicity of the entire raw material is small, and the raw material is cheap and easy to obtain, thereby significantly reducing the cost and the pollution to the environment. In addition, no high-pressure reactor or other equipment is used in the entire process, and the reaction can be completed at normal temperature and pressure, which is small in danger, simple in operation, safe and reliable, reduces the equipment investment cost, and at the same time, the by-product of the reaction is inorganic halide, which is easy to recycle and treat, greatly reducing the pollution to the environment, and the product yield is high. Therefore, the method is simple in operation, safe and reliable, easy to obtain raw materials, low in cost, environmentally friendly, and high in product yield.
[0025] In addition, the method for preparing the hindered amine light stabilizer UV-371 according to the above embodiments of the application can also have the following technical features:
[0026] In some embodiments of the application, in step (1), the compound shown in Formula 1, the oxidizing agent and the catalyst are subjected to an oxidation reaction in a first solvent; and / or the first solvent comprises at least one of toluene, xylene and ethyl acetate.
[0027] In some embodiments of the application, the mass ratio of the compound shown in Formula 1 and the catalyst is 100:(0.1-5). In some embodiments of the application, the molar ratio of the compound shown in Formula 1 and the oxidizing agent is 1:(20-40).
[0028] In some embodiments of the application, the temperature of the oxidation reaction is 25-100°C, and the time of the oxidation reaction is 6-24h.
[0029] In some embodiments of the application, the oxidizing agent comprises at least one of hydrogen peroxide and tert-butyl hydroperoxide.
[0030] In some embodiments of the application, the catalyst comprises at least one of sodium bicarbonate, magnesium sulfate and magnesium acetate.
[0031] In some embodiments of the application, in step (2), the compound shown in Formula 2 is subjected to a reduction reaction in a second solvent and an aqueous solution of the reducing agent; and / or the second solvent comprises at least one of toluene, xylene and ethyl acetate; and / or the concentration of the reducing agent in the aqueous solution of the reducing agent is 5wt%-40wt%.
[0032] In some embodiments of the application, the temperature of the reduction reaction is 40-80°C, and the time of the reduction reaction is 2-6h.
[0033] In some embodiments of the application, the mass ratio of the compound of formula 2 to the reducing agent is 100:(22-80).
[0034] In some embodiments of the application, the reducing agent comprises at least one of Vc and sodium sulfite.
[0035] In some embodiments of the application, the reducing agent is Vc, and the mass ratio of the compound of formula 2 to the reducing agent is 100:(27-80).
[0036] In some embodiments of the application, the reducing agent is sodium sulfite, and the mass ratio of the compound of formula 2 to the reducing agent is 100:(22-40).
[0037] In some embodiments of the application, in step (3), the compound of formula 3, the propyl halide and the acid-binding agent undergo a substitution reaction in a third solvent; and / or the third solvent comprises at least one of toluene, xylene and ethyl acetate.
[0038] In some embodiments of the application, the temperature of the substitution reaction is 60-120°C, and the time of the substitution reaction is 10-24h.
[0039] In some embodiments of the application, the propyl halide comprises at least one of chloropropane, bromopropane and iodopropane.
[0040] In some embodiments of the application, the acid-binding agent comprises at least one of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate.
[0041] In some embodiments of the application, the molar ratio of the compound of formula 3 to the propyl halide is 1:(10-20);
[0042] In some embodiments of the application, the molar ratio of the propyl halide to the acid-binding agent is 1:(1-2).
[0043] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the application. DETAILED DESCRIPTION
[0044] Embodiments of the application are described below in detail with the purpose of explaining the application and are not to be understood as limiting the application.
[0045] In one aspect of the application, the application provides a method for preparing a hindered amine light stabilizer UV-371. According to embodiments of the application, the method comprises:
[0046] S100: the compound shown in formula 1, the oxidizing agent and the catalyst are subjected to an oxidation reaction
[0047] In this step, the compound shown in formula 1, the oxidizing agent and the catalyst are subjected to an oxidation reaction, thereby obtaining the compound shown in formula 2, and the specific reaction equation is as follows:
[0048]
[0049] It should be noted that the oxidizing agent and the catalyst are conventional materials in the art, and those skilled in the art can select the specific types of the oxidizing agent and the catalyst according to the actual situation, for example, the oxidizing agent includes but is not limited to at least one of hydrogen peroxide and tert-butyl hydroperoxide; the catalyst includes but is not limited to at least one of sodium bicarbonate, magnesium sulfate and magnesium acetate.
[0050] According to an embodiment of the present application, the compound shown in formula 1, the oxidizing agent and the catalyst are subjected to an oxidation reaction in a first solvent. Further, the first solvent includes at least one of toluene, xylene and ethyl acetate. It should be noted that the first solvent provides a reaction environment, and the amount of the specific first solvent used can be selected by those skilled in the art according to the actual situation.
[0051] According to an embodiment of the present application, the mass ratio of the compound shown in formula 1 to the catalyst is 100:(0.1-5). The inventors have found that when the mass ratio of the compound shown in formula 1 to the catalyst is controlled within the above range, not only can the reaction be promoted, the reaction speed and yield be improved, but also the amount of the catalyst used can be saved to the maximum extent.
[0052] According to an embodiment of the present application, the molar ratio of the compound shown in formula 1 to the oxidizing agent is 1:(20-40). The inventors have found that when the molar ratio of the compound shown in formula 1 to the oxidizing agent is controlled within the above range, not only can the compound shown in formula 1 be completely oxidized to the compound shown in formula 2, but also the amount of the oxidizing agent used can be saved to the maximum extent.
[0053] According to an embodiment of the present application, the temperature of the oxidation reaction is 25-100°C, and the time of the oxidation reaction is 6-24h. The inventors have found that by controlling the temperature and time of the oxidation reaction within the above range, the compound shown in formula 1 can be fully oxidized with the oxidizing agent, thereby obtaining the compound shown in formula 2.
[0054] S200: the compound shown in formula 2 and a reducing agent are subjected to a reduction reaction
[0055] In this step, the compound shown in formula 2 and a reducing agent are subjected to a reduction reaction, thereby obtaining the compound shown in formula 3, and the specific reaction equation is as follows:
[0056]
[0057] According to an embodiment of the present application, the compound of formula 2 is subjected to a reduction reaction in a second solvent and an aqueous solution of a reducing agent. Further, the second solvent comprises at least one of toluene, xylene and ethyl acetate; the concentration of the reducing agent in the aqueous solution of the reducing agent is 5wt% to 40wt%. The aqueous solution of the reducing agent can provide water for the reduction reaction, ensuring the smooth progress of the reaction. It should be noted that the compound of formula 2 obtained in S100 is in a dissolved organic solvent, in order to reduce the energy consumption and time of the reaction, the organic solvent containing the compound of formula 2 prepared in S100 can be directly subjected to a reduction reaction with the aqueous solution of the reducing agent in S200 of the present application, thereby saving the process steps and the use of the second solvent.
[0058] According to an embodiment of the present application, the temperature of the reduction reaction is 40℃ to 80℃, and the time of the reduction reaction is 2h to 6h. The inventors have found that controlling the temperature and time of the reduction reaction within the above ranges can ensure the safe occurrence of the reaction and improve the reaction efficiency.
[0059] According to an embodiment of the present application, the mass ratio of the compound of formula 2 to the reducing agent is 100:(22-80). The inventors have found that controlling the mass ratio of the compound of formula 2 to the reducing agent within the above range can ensure the reduction of the compound of formula 2 to the compound of formula 3, and also achieve the saving of the amount of the reducing agent and the reduction of the discharge of three wastes.
[0060] According to an embodiment of the present application, the reducing agent comprises at least one of Vc and sodium sulfite, so that the compound of formula 2 can be effectively reduced to the compound of formula 3.
[0061] According to an embodiment of the present application, the reducing agent is Vc, and the mass ratio of the compound of formula 2 to the reducing agent is 100:(27-80), so that the compound of formula 2 can be ensured to be reduced to the compound of formula 3, and also achieve the saving of the amount of the reducing agent and the reduction of the discharge of three wastes.
[0062] According to an embodiment of the present application, the reducing agent is sodium sulfite, and the mass ratio of the compound of formula 2 to the reducing agent is 100:(22-40), so that the compound of formula 2 can be ensured to be reduced to the compound of formula 3, and also achieve the saving of the amount of the reducing agent and the reduction of the discharge of three wastes.
[0063] S300: substitution reaction of the compound of formula 3, propyl halide and acid binding agent
[0064] In this step, the compound of formula 3, propyl halide and acid binding agent are subjected to a substitution reaction, thereby obtaining the hindered amine light stabilizer UV-371, and the specific reaction process is as follows:
[0065] The process does not use organic solvents such as butyraldehyde which is seriously polluting, the entire raw material is less toxic, and the raw material is cheap and easy to obtain, thereby significantly reducing the cost and pollution to the environment. Secondly, the entire process does not use high-pressure reactors and other equipment, and the reaction can be completed at normal temperature and pressure, which is less dangerous, simple to operate, safe and reliable, reduces the cost of equipment investment, and at the same time, the by-product of the reaction is inorganic halide, which is easy to recover and process, greatly reducing the pollution to the environment, and the product yield is high. It should be noted that the propyl halide and the acid binding agent are conventional reagents in the art, and those skilled in the art can select them according to the actual situation, for example, the propyl halide includes but is not limited to at least one of chloropropane, bromopropane and iodopropane; the acid binding agent includes but is not limited to at least one of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate.
[0066] According to an embodiment of the present application, the compound represented by formula 3, the propyl halide and the acid binding agent undergo a substitution reaction in a third solvent. Further, the third solvent includes at least one of toluene, xylene and ethyl acetate. It should be noted that the compound represented by formula 3 obtained in S200 is in a dissolved organic solvent, in order to reduce the energy consumption and time of the reaction, the organic solvent containing the compound represented by formula 3 prepared in S200 can be directly used for the substitution reaction with the propyl halide and the acid binding agent in the present application S300, thereby saving the process steps and the use of the third solvent.
[0067] According to an embodiment of the present application, the temperature of the substitution reaction is 60-120°C, and the time of the substitution reaction is 10-24h. The inventors found that when the temperature and time of the substitution reaction are controlled within the above range, the compound represented by formula 3 can smoothly undergo a substitution reaction with the propyl halide, thereby obtaining the hindered amine light stabilizer UV-371. Further, the compound represented by formula 3, the propyl halide and the acid binding agent are reacted in the third solvent at the above temperature, then washed with water, separated into layers, filtered and evaporated to dryness to obtain the hindered amine light stabilizer UV-371.
[0068] According to an embodiment of the present application, the molar ratio of the compound represented by formula 3 to the propyl halide is 1:(10-20). The inventors found that when the molar ratio of the compound represented by formula 3 to the propyl halide is controlled within the above range, the compound represented by formula 3 can be completely substituted to generate the target product UV-371, and the propyl halide can be saved, and the discharge of three wastes can be reduced. Further, the molar ratio of the propyl halide to the acid binding agent is 1:(1-2).
[0069] The present application will be described below with reference to specific examples, and it should be noted that these examples are merely descriptive and do not limit the present application in any way.
[0070] Example 1
[0071] (1) In a three-necked flask, 15 g of the compound shown in formula 1, 60 ml of toluene were added, stirred, dissolved, 0.2 g of sodium bicarbonate was added, and the temperature was raised to 35-40°C. 20 ml of 30 wt% hydrogen peroxide was added dropwise, which took about 2 h. After the dropwise addition was completed, the reaction was continued at 35-40°C for 20 h. The stirring was stopped, and the water layer was separated. The organic layer was directly subjected to the next reaction, or the organic layer was distilled to obtain a dark orange solid 15.3 g (the compound shown in formula 2). Theoretically, 15 g of the compound shown in formula 1 would obtain 15.75 g of the compound shown in formula 2. Therefore, in step (1), the yield of the compound shown in formula 2 was 97.14%.
[0072] (2) The organic layer containing the compound shown in formula 2 from the previous step was added to a three-necked flask, stirred, and the temperature was raised to 50-55°C. A solution of 5.0 g of Vc and 30 ml of water was added dropwise, which took about 20 min. After the dropwise addition was completed, the reaction was continued at 50-55°C for 2 h. The stirring was stopped, and the water layer was separated. The organic layer was directly subjected to the next reaction, or the organic layer was distilled to obtain a white powder 15.3 g (the compound shown in formula 3). Theoretically, 15.8 g of the compound shown in formula 3 would be obtained. Therefore, in step (2), the yield of the compound shown in formula 3 was 96.84%.
[0073] (3) The organic layer containing the compound shown in formula 3 from the previous step was added to a three-necked flask, stirred, 3.0 g of sodium hydroxide solid was added, 8 g of n-propyl bromide was added, and the temperature was raised to reflux to remove water for 12 h. The reaction temperature was 80-85°C. After the temperature was lowered to no reflux, 30 ml of water was added, stirred for 5 min, the stirring was stopped, the water layer was separated, and the organic layer was washed twice with 30 ml of water. Then, the filtrate was distilled to dryness to obtain the product hindered amine light stabilizer UV-371: 16.4 g. Theoretically, 17.9 g of the hindered amine light stabilizer UV-371 would be obtained. Therefore, in step (3), the yield of the hindered amine light stabilizer UV-371 was 91.62%.
[0074] Example 2
[0075] (1) In a three-necked flask, 15 g of the compound shown in formula 1, 60 ml of toluene were added, stirred, dissolved, 0.2 g of sodium bicarbonate was added, and the temperature was raised to 35-40°C. 20 ml of 30 wt% hydrogen peroxide was added dropwise, which took about 2 h. After the dropwise addition was completed, the reaction was continued at 35-40°C for 20 h. The stirring was stopped, and the water layer was separated. The organic layer was directly subjected to the next reaction, or the organic layer was distilled to obtain a dark orange solid 15.3 g (the compound shown in formula 2). Theoretically, 15 g of the compound shown in formula 1 would obtain 15.75 g of the compound shown in formula 2. Therefore, in step (1), the yield of the compound shown in formula 2 was 97.14%.
[0076] (2) The organic layer containing the compound of formula 2 from the previous step was added to a flask, stirred, and warmed to 50-55°C. A solution of 3.5 g of sodium sulfite in 30 ml of water was added dropwise over a period of about 0.5 h. After the addition was complete, the reaction was continued at 50-55°C for 5 h. The stirring was stopped and the mixture was allowed to stand for 15 min. The aqueous layer was separated and the organic layer was used directly in the next step or the solvent was distilled off to give a white powder, 15.4 g of the compound of formula 3 (yield: 97.47%).
[0077] (3) The organic layer containing the compound of formula 3 from the previous step was added to a flask, stirred, and 3.0 g of sodium hydroxide was added. Then, 8 g of n-propyl bromide was added and the reaction was carried out at reflux for 16 h at a temperature of 88-92°C. After the reaction was completed, the temperature was lowered to a point where reflux was no longer observed, 30 ml of water was added, and the mixture was stirred for 5 min. The stirring was stopped and the aqueous layer was separated. The organic layer was washed twice with 30 ml of water, filtered, and the filtrate was distilled to dryness to give the product, hindered amine light stabilizer UV-371, 16.2 g (yield: 90.5%).
[0078] Example 3
[0079] (1) A flask was charged with 15 g of the compound of formula 1, 60 ml of toluene, and 0.3 g of magnesium sulfate. The mixture was stirred and warmed to 60-65°C. A solution of 15 ml of 70 wt% tert-butyl hydroperoxide in water was added dropwise over a period of about 1.5 h. After the addition was complete, the reaction was continued at 60-65°C for 10 h. The stirring was stopped and the aqueous layer was separated. The organic layer was used directly in the next step or the solvent was distilled off to give a dark orange solid, the compound of formula 2, 15.0 g (yield: 95.24%).
[0080] (2) The organic layer containing the compound of formula 2 from the previous step was added to a flask, stirred, and warmed to 70-75°C. A solution of 4.0 g of sodium sulfite in 30 ml of water was added dropwise over a period of about 0.5 h. After the addition was complete, the reaction was continued at 70-75°C for 2 h. The stirring was stopped and the mixture was allowed to stand for 15 min. The aqueous layer was separated and the organic layer was used directly in the next step or the solvent was distilled off to give a white powder, 15.3 g of the compound of formula 3 (yield: 96.84%).
[0081] (3) The organic layer containing the compound of formula 3 from the previous step was added to a flask, stirred, and 3.5 g of sodium hydroxide was added. Then, 10 g of n-propyl bromide was added and the reaction was carried out at reflux for 12 h at a temperature of 80-85°C. After the reaction was completed, the temperature was lowered to a point where reflux was no longer observed, 30 ml of water was added, and the mixture was stirred for 5 min. The stirring was stopped and the aqueous layer was separated. The organic layer was washed twice with 30 ml of water, filtered, and the filtrate was distilled to dryness to give the product, hindered amine light stabilizer UV-371, 16.3 g (yield: 91.06%).
[0082] Example 4
[0083] (1) In a three-necked flask, add 15 g of the compound shown in formula 1, 60 ml of ethyl acetate, stir, dissolve, then add 0.2 g of sodium bicarbonate, and heat to 65-70°C. Drop 20 ml of 30 wt% hydrogen peroxide solution in about 1.5 h. Continue to react at 65-70°C for 10 h after dropping. Stop stirring, separate the water layer, and directly proceed to the next step reaction or distill the solvent from the organic layer to obtain 15.2 g of dark orange red solid (the compound shown in formula 2) with a yield of 96.51%.
[0084] (2) Add the organic layer containing the compound shown in formula 2 from the previous step to a three-necked flask, stir, and heat to 40-45°C. Drop 5.0 g of sodium sulfite and 30 ml of water solution in about 0.5 h. Continue to react at 40-45°C for 4 h after dropping. Stop stirring, stand for 15 min, separate the water layer, and directly proceed to the next step reaction or distill the solvent from the organic layer to obtain 15.1 g of white powder (the compound shown in formula 3) with a yield of 95.57%.
[0085] (3) Add the compound shown in formula 3 from the previous step to a three-necked flask, add 60 ml of dimethylbenzene, stir, dissolve, add 2.2 g of sodium hydroxide solid, and 6.5 g of n-propyl bromide. Heat to reflux and remove water for 20 h with a reaction temperature of 70-73°C. After cooling to no reflux, add 30 ml of water, stir for 5 min, stop stirring, separate the water layer, wash twice with 30 ml of water, filter the organic layer, and then distill the filtrate to dryness to obtain the product hindered amine light stabilizer UV-371: 16.3 g with a yield of 91.1%.
[0086] Example 5
[0087] (1) In a three-necked flask, add 15 g of the compound shown in formula 1, 60 ml of ethyl acetate, stir, dissolve, then add 0.2 g of sodium bicarbonate, and heat to 65-70°C. Drop 20 ml of 30 wt% hydrogen peroxide solution in about 1.5 h. Continue to react at 65-70°C for 10 h after dropping. Stop stirring, separate the water layer, and directly proceed to the next step reaction or distill the solvent from the organic layer to obtain 15.2 g of dark orange red solid (the compound shown in formula 2) with a yield of 96.51%.
[0088] (2) Add the organic layer containing the compound shown in formula 2 from the previous step to a three-necked flask, stir, and heat to 40-45°C. Drop 5.0 g of sodium sulfite and 30 ml of water solution in about 0.5 h. Continue to react at 40-45°C for 4 h after dropping. Stop stirring, stand for 15 min, separate the water layer, and directly proceed to the next step reaction or distill the solvent from the organic layer to obtain 15.1 g of white powder (the compound shown in formula 3) with a yield of 95.57%.
[0089] (3) The organic layer containing the compound of Formula 3 from the previous step was added to a flask, stirred, 3.0 g of sodium hydroxide solid was added, 10 g of n-propyl iodide was added, and the reaction was refluxed for 10 h at a temperature of 80-85 °C. After the reaction was cooled to stop refluxing, 30 ml of water was added, stirred for 5 min, and then the stirring was stopped. The water layer was separated, and the organic layer was washed twice with 30 ml of water. The organic layer was filtered, and then the filtrate was distilled to dryness to obtain the product hindered amine light stabilizer UV-371: 16.5 g, yield: 92.2%.
[0090] Example 6
[0091] (1) In a flask, 15 g of the compound of Formula 1, 40 ml of toluene was added, stirred, and dissolved. Then, 0.2 g of magnesium acetate was added, and the temperature was raised to 65-70 °C. 20 ml of 30 wt% hydrogen peroxide was added dropwise, and the reaction was continued at 65-70 °C for 15 h. After the stirring was stopped, the water layer was separated, and the organic layer was directly used for the next step or was distilled to obtain a dark orange solid of 15.5 g (the compound of Formula 2), yield: 98.4%.
[0092] (2) The organic layer containing the compound of Formula 2 from the previous step was added to a flask, stirred, and the temperature was raised to 40-45 °C. 8.0 g of Vc was dissolved in 30 ml of water, and the solution was added dropwise, and the reaction was continued at 40-45 °C for 4 h. After the stirring was stopped, the water layer was separated, and the organic layer was directly used for the next step or was distilled to obtain a white powder of 15.1 g (the compound of Formula 3), yield: 95.3%.
[0093] (3) The organic layer containing the compound of Formula 3 from the previous step was added to a flask, stirred, 3.2 g of potassium hydroxide solid was added, 10 g of n-propyl iodide was added, and the reaction was refluxed for 12 h at a temperature of 80-85 °C. After the reaction was cooled to stop refluxing, 30 ml of water was added, stirred for 5 min, and then the stirring was stopped. The water layer was separated, and the organic layer was washed twice with 30 ml of water. The organic layer was filtered, and then the filtrate was distilled to dryness to obtain the product hindered amine light stabilizer UV-371: 16.4 g, yield: 91.6%.
[0094] Example 7
[0095] (1) In a flask, 15 g of the compound of Formula 1, 40 ml of toluene was added, stirred, and dissolved. Then, 0.2 g of magnesium acetate was added, and the temperature was raised to 65-70 °C. 20 ml of 30 wt% hydrogen peroxide was added dropwise, and the reaction was continued at 65-70 °C for 15 h. After the stirring was stopped, the water layer was separated, and the organic layer was directly used for the next step or was distilled to obtain a dark orange solid of 15.5 g (the compound of Formula 2), yield: 98.4%.
[0096] (2) The organic layer containing the compound of Formula 2 from the previous step was added to a flask, stirred, and warmed to 60-65°C. A solution of 10.0 g of Vc in 30 ml of water was added dropwise over a period of about 20 min. The reaction was continued at 60-65°C for 2 h after the dropwise addition was completed. The stirring was stopped and the mixture was allowed to stand for 15 min. The aqueous layer was separated and the organic layer was used directly in the next step or the organic layer was distilled to give a white powder of 15.2 g (compound of Formula 3) with a yield of 96.2%.
[0097] (3) The organic layer containing the compound of Formula 3 from the previous step was added to a flask, stirred, and 10.0 g of potassium carbonate and 10 g of n-propyl iodide were added. The reaction was carried out at reflux for 10 h at a temperature of 80-85°C. After the reaction was completed, the temperature was lowered to stop the reflux. Then, 30 ml of water was added and the mixture was stirred for 5 min. The stirring was stopped and the aqueous layer was separated. The organic layer was washed with 30 ml of water twice. The organic layer was filtered and the filtrate was distilled to give the product, hindered amine light stabilizer UV-371, in an amount of 16.3 g with a yield of 91.1%.
[0098] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the different embodiments or examples described in the present specification and the features of the different embodiments or examples can be combined and modified by those skilled in the art without contradiction, if necessary.
[0099] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.
Claims
1. A method for preparing a hindered amine light stabilizer UV-371, characterized in that, include: (1) The compound shown in Formula 1, the oxidant and the catalyst undergo an oxidation reaction to obtain the compound shown in Formula 2; (2) The compound shown in Formula 2 undergoes a reduction reaction with a reducing agent to obtain the compound shown in Formula 3; (3) The compound shown in Formula 3, the propyl halide and the acid-binding agent undergo a substitution reaction to obtain the hindered amine light stabilizer UV-371; 2. The method according to claim 1, characterized in that, In step (1), the compound shown in Formula 1, the oxidant, and the catalyst undergo an oxidation reaction in the first solvent; And / or the first solvent includes at least one of toluene, xylene, and ethyl acetate.
3. The method according to claim 1 or 2, characterized in that, The mass ratio of the compound shown in Formula 1 to the catalyst is 100:(0.1-5); Optionally, the molar ratio of the compound shown in Formula 1 to the oxidant is 1:(20-40); Optionally, the oxidation reaction is carried out at a temperature of 25°C to 100°C for a duration of 6 hours to 24 hours. Optionally, the oxidant includes at least one of hydrogen peroxide and tert-butyl hydrogen peroxide; Optionally, the catalyst comprises at least one of sodium bicarbonate, magnesium sulfate, and magnesium acetate.
4. The method according to claim 1, characterized in that, In step (2), the compound represented by formula 2 undergoes a reduction reaction with the aqueous solution of the reducing agent in the second solvent; And / or the second solvent includes at least one of toluene, xylene, and ethyl acetate; And / or the concentration of the reducing agent in the aqueous solution of the reducing agent is 5 wt% to 40 wt%.
5. The method according to claim 1 or 4, characterized in that, The reduction reaction is carried out at a temperature of 40℃ to 80℃ for 2 hours to 6 hours.
6. The method according to claim 1 or 4, characterized in that, The mass ratio of the compound shown in Formula 2 to the reducing agent is 100:(22-80); Optionally, the reducing agent includes at least one of vitamin C and sodium sulfite.
7. The method according to claim 6, characterized in that, The reducing agent is Vc, and the mass ratio of the compound shown in Formula 2 to the reducing agent is 100:(27-80); Optionally, the reducing agent is sodium sulfite, and the mass ratio of the compound shown in Formula 2 to the reducing agent is 100:(22-40).
8. The method according to claim 1, characterized in that, In step (3), the compound shown in Formula 3, the propyl halide, and the acid-binding agent undergo a substitution reaction in a third solvent; And / or the third solvent includes at least one of toluene, xylene, and ethyl acetate.
9. The method according to claim 1 or 8, characterized in that, The temperature of the substitution reaction is 60℃~120℃, and the time of the substitution reaction is 10h~24h; Optionally, the propyl halide includes at least one of chloropropane, bromopropane, and iodopropane; Optionally, the acid-binding agent includes at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.
10. The method according to claim 1 or 8, characterized in that, The molar ratio of the compound shown in Formula 3 to the propyl halide is 1:(10-20); Optionally, the molar ratio of the propyl halide to the acid-binding agent is 1:(1-2).