Preparation process of pinacolone derivative

Abstract

The invention provides a pinacolone derivative preparation process, and relates to the technical field of chemical synthesis. The preparation process provided by the invention comprises the following steps: carrying out hydrogenation reaction on a raw material 1-(4-chlorphenyl)-4, 4-dimethyl-1-ene-3-pentanone and H2 under the action of a catalyst to prepare 1-(4-chlorphenyl)-4, 4-dimethyl-3-pentanone; wherein the catalyst is stannous chloride / triphenylphosphine sulfide / palladium carbon complex or stannous chloride / triphenylphosphine oxide / palladium carbon complex. The catalyst disclosed by the invention can be used for efficiently and highly selectively catalyzing hydrogenation of 1-(4-chlorphenyl)-4, 4-dimethyl-1-ene-3-pentanone to prepare 1-(4-chlorphenyl)-4, 4-dimethyl-3-pentanone, the reaction yield is high, the content of a dechlorination product is low, and the reaction time is short; the catalyst does not need to be replenished in the cyclic application process of the used catalyst; according to the pinacolone derivative preparation process, the consumption of palladium metal is reduced, the process is greatly simplified, the production cost is saved, and the pinacolone derivative preparation process has important industrial application value.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical synthesis, and particularly relates to a preparation method of a pinacolone derivative 3-pentanone (1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone). Background Art

[0002] The preparation of the pinacolone derivative 3-pentanone (1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone) is a key intermediate of tebuconazole. Tebuconazole is used as a seed treatment agent and foliar spray worldwide, and has advantages such as a broad fungicidal spectrum, high activity, and a long effective period. For example, when tebuconazole is used to control Sclerotinia sclerotiorum of rapeseed, it can inhibit the demethylation of ergosterol on the cell membrane of the pathogen, so that the pathogen cannot form a cell membrane and thus kill the pathogen. It not only has a good control effect, but also has obvious characteristics such as anti-lodging and yield increase. The wide application of tebuconazole has led to an increasing demand for the preparation of the pinacolone derivative 3-pentanone.

[0003] There are many studies on the synthesis of tebuconazole. Among them, p-chlorobenzaldehyde is mostly used as the starting material, and tebuconazole is prepared through steps such as aldol condensation, catalytic hydrogenation, epoxidation reaction, and addition reaction. For example:

[0004] "Pesticide Science and Administration" (2004, 25, 23-25) reported that this key intermediate 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone was prepared by a hydrogenation reaction. However, in this preparation method, a dehalogenation inhibitor (promoter) was not added, resulting in a relatively large amount of dechlorination products, and the yield and purity of the product were both low.

[0005] Patent CN105348057 reported a synthesis method of a tebuconazole intermediate. This method reduced the occurrence of dechlorination side reactions by using a dehalogenation inhibitor, reduced the content of dehalogenation products, and significantly improved the yield and content of the product. However, in this patent, the catalyst was not recycled, and the process cost was still relatively high.

[0006] Patent CN112062662A proposes a preparation method of 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone. The method includes mixing the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one with methanol evenly in an autoclave. The mass ratio of methanol to the raw material is 2-3:1. A catalyst and a cocatalyst are added to the mixture. The gas in the autoclave is replaced successively with a mixed gas of nitrogen and hydrogen, and then hydrogen is introduced. The reaction is carried out at 40-100°C and a hydrogenation pressure of 0.1-2.0 MPa. After the reaction is completed, through pressure relief, pressure filtration, water washing and desolvation, the said 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone is obtained. By improving the process, the reaction yield of this method is increased to 98%, the content is increased to 98.5%, the catalyst can be reused 20 times, and the content of the dechlorination product does not exceed 0.4%. However, the contents of the dechlorination product and the carbonyl hydrogenation product are still relatively high for high-quality products, and a cocatalyst needs to be replenished every time this method is operated.

[0007] Patent CN118344245A discloses a preparation method of 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone. The method includes: dispersing 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one, a dechlorination inhibitor and a catalyst in an organic solvent, and carrying out a hydrogenation reaction in a hydrogen atmosphere to obtain the said 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone; the dechlorination inhibitor is dimethyl sulfoxide and / or dimethyl sulfide. This patent reports that the comprehensive effect of using methanol as a solvent is acceptable, and the selectivity of the hydrogenation reaction assisted by dimethyl sulfide or dimethyl sulfoxide is good. However, the reproducibility of this method is not good in large-scale industrial production; and this patent is only realized in the small-scale test stage, and the maximum raw material feeding amount is only 200 grams, which is not suitable for industrial production; in addition, the maximum amount of dimethyl sulfoxide added as an inhibitor reaches 10% of the substrate raw material. Therefore, the operation of distilling out the solvent in this process after industrialization will correspondingly increase the additional workload and cost investment.

[0008] Patent CN116730816A discloses a preparation method of 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone. The method dissolves 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one in a solvent and adjusts the pH of the system to 9-12, and then hydrogen is introduced. The reaction is carried out under the action of a metal catalyst and a cocatalyst to obtain the said 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone. This patent reports that the comprehensive effect is acceptable. However, the post-treatment requires a water washing process, resulting in the generation of a large amount of wastewater, increasing the environmental protection pressure and the subsequent treatment cost; in addition, the catalyst of this patent can be recycled about 30 times, and a new metal catalyst needs to be added during the recycling process to maintain the catalytic activity.

[0009] Patent CN112654425A discloses a palladium-containing composition and a method for manufacturing hydrogen peroxide. The palladium-containing composition provided by this method contains palladium particles and a coating agent that coats the surface of the palladium particles. The palladium-containing composition catalyst formed in this patent exists in a liquid form, which is not conducive to recycling in actual applications and will increase the process cost. Summary of the Invention

[0010] Aiming at the deficiencies in the prior art, the present invention discloses a process for preparing pinacolone derivatives. This process has high selectivity and yield, low by-product content, can perform high-activity recycling of the catalyst, reduce catalyst consumption, and effectively reduce the process cost.

[0011] To achieve the above technical objectives, the present invention proposes a process for preparing pinacolone derivatives, which includes: The raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-en-3-pentanone undergoes a hydrogenation reaction with H2 under the action of a catalyst to obtain 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone; wherein, the catalyst is stannous chloride / triphenylphosphine sulfide / palladium-carbon complex or stannous chloride / triphenylphosphine oxide / palladium-carbon complex.

[0012] The reaction process of the preparation process of the present invention is as follows:

[0013]

[0014] Through a large number of exploratory experiments, the R & D team of the present invention found that: When palladium is used as the catalyst for the hydrogenation reaction of 1-(4-chlorophenyl)-4,4-dimethyl-1-en-3-pentanone to prepare 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone, when the dosage of palladium relative to the raw material is too high, although the reaction efficiency increases and the reaction time decreases, it may lead to a decrease in reaction selectivity and an increase in the content of dechlorination products. Therefore, the addition amount of palladium should not be too high; however, it is not that the lower the relative amount of palladium is, the better. When the amount of palladium used is low, the reaction efficiency decreases, the reaction time prolongs, the selectivity of the reaction also decreases, and the content of dechlorination products increases. To provide an efficient preparation process suitable for industrial production and solve the technical problems of too high palladium-carbon reduction and low product selectivity in the existing process for preparing 3-pentanone of pinacolone derivatives, the R & D team of the present invention attempts to regulate the catalytic activity of the palladium catalyst by means of coordination complexation, while providing the reaction efficiency and reducing the occurrence of side reactions.

[0015] As described above, in the existing processes, the preparation of 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone is often carried out by adding a dehalogenation inhibitor as a cocatalyst. However, these processes have the disadvantages of low catalyst recycling times, gradually decreasing catalytic activity, and thus the need to replenish the catalyst or the cocatalyst. Palladium is a relatively expensive metal, and for large-scale industrial production, the operability of these processes is relatively poor and the operating cost is relatively high.

[0016] Based on the exploratory experiments on the catalysis of palladium catalysts in different forms, the R & D team of the present invention innovatively uses stannous chloride / triphenylphosphine sulfide / palladium carbon complex, or stannous chloride / triphenylphosphine oxide / palladium carbon complex as a catalyst to catalyze the hydrogenation reaction of 1-(4-chlorophenyl)-4,4-dimethyl-1-ene-3-pentanone. Through the coordination complexation of the electron-rich benzene ring group in triphenylphosphine sulfide or triphenylphosphine oxide with palladium metal, the catalytic activity of palladium can be regulated during the catalytic process to control the selective hydrogenation reaction process. The addition of stannous chloride provides a Lewis acid environment that can promote the formation of the complex catalyst, and finally a high-quality pinacolone derivative, 3-pentanone, is obtained.

[0017] More importantly, the catalyst used in the present invention can be recycled multiple times, and the catalytic activity of palladium will not be reduced during the recycling process. Thus, the consumption of palladium metal is reduced, and high-selectivity and high-yield continuous production can be achieved without replenishing the catalyst. This will greatly simplify the process flow and reduce the process cost in large-scale industrial production.

[0018] The exploration examples of the present invention illustrate the above exploration process. The examples of the present invention illustrate the effects of using stannous chloride / triphenylphosphine sulfide / palladium carbon complex, or stannous chloride / triphenylphosphine oxide / palladium carbon complex as a catalyst to catalyze the hydrogenation reaction of 1-(4-chlorophenyl)-4,4-dimethyl-1-ene-3-pentanone on the product purity, yield, content of dechlorination products, and reaction time.

[0019] Based on the above technical solutions, the present invention explores and optimizes the dosage of triphenylphosphine oxide or triphenylphosphine sulfide in the catalyst. Optionally, when the catalyst is stannous chloride / triphenylphosphine sulfide / palladium carbon complex, the molar ratio of triphenylphosphine sulfide to palladium in palladium carbon is (3 - 8):1, preferably (3 - 6):1, and further preferably (3 - 5):1; when the catalyst is stannous chloride / triphenylphosphine oxide / palladium carbon complex, the molar ratio of triphenylphosphine oxide to palladium in palladium carbon is (3 - 8):1, preferably (3 - 6):1, and further preferably (3 - 4):1.

[0020] Based on the above technical solutions, the present invention explores and optimizes the dosage of stannous chloride in the catalyst. Optionally, the dosage of stannous chloride is 0.3-1% of the mass of triphenylsulfide or triphenylphosphine oxide. The appropriate dosage of stannous chloride can provide a suitable Lewis acid environment for the formation of the complex catalyst; in an alternative example of the invention, the dosage of stannous chloride is 5% of the mass of triphenylsulfide or triphenylphosphine oxide.

[0021] Based on the above technical solutions, the present invention explores the preparation method of the catalyst. Optionally, the preparation method of the catalyst includes: coordinating and complexing palladium-carbon with stannous chloride / triphenylphosphine sulfide, or palladium-carbon with stannous chloride / triphenylphosphine oxide in a first solvent to obtain the catalyst. In the actual operation process, it is optional to promote the coordination and complexation of palladium-carbon with stannous chloride / triphenylphosphine sulfide or palladium-carbon with stannous chloride / triphenylphosphine oxide by means of stirring or homogenization. For example, after adding palladium-carbon and stannous chloride / triphenylphosphine sulfide, or palladium-carbon and stannous chloride / triphenylphosphine oxide to the first solvent, stir for 2-6 h and then filter to obtain the catalyst.

[0022] Further optionally, the first solvent includes at least one of methanol or ethanol. Examples of the present invention illustrate examples of preparing the catalyst using different first solvents.

[0023] Further optionally, the palladium loading in the palladium-carbon is 5 wt% - 10 wt%.

[0024] Based on the above technical solutions, the present invention explores and optimizes the addition amount of palladium in the hydrogenation reaction. Optionally, the mass of palladium in the catalyst can be 0.05% - 5% of the mass of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-en-3-pentanone, preferably 0.5% - 5%, and more preferably 1.5% - 3%. Examples of the present invention illustrate the exploration and optimization process.

[0025] Based on the above technical solutions, the present invention explores and optimizes the control conditions of the hydrogenation reaction.

[0026] Optionally, the temperature of the hydrogenation reaction is 50 - 90 °C, preferably 60 - 90 °C, and more preferably 60 - 70 °C. Within this temperature control range, a high-purity 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone product can be obtained in high yield, and the reaction efficiency is relatively high. Examples of the present invention illustrate the exploration and optimization process of the hydrogenation reaction temperature.

[0027] Optionally, when the catalyst is stannous chloride / triphenylphosphine sulfide / palladium on carbon complex, the pressure of the hydrogenation reaction is 0.4 to 1.3 MPa, preferably 0.6 to 1.3 MPa, more preferably 0.9 - 1.3 MPa; when the catalyst is stannous chloride / triphenylphosphine oxide / palladium on carbon complex, the pressure of the hydrogenation reaction is 0.7 to 1.3 MPa, preferably 0.9 to 1.3 MPa. Within this reaction pressure control range, a high-purity 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone product can be obtained efficiently and with high yield. The examples of the present invention illustrate the exploration and optimization process of the hydrogenation reaction pressure.

[0028] Optionally, the hydrogenation reaction is carried out in the solvent methanol; further optionally, the amount of the second solvent is 1 to 10 times the mass of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-ene-3-pentanone. The optimization of the amount of the second solvent is beneficial to improving the reaction rate and reducing the process cost.

[0029] Based on the above technical solution, the preparation process of the pinacolone derivative of the present invention further includes a post-treatment process: after the reaction material is cooled and depressurized, the catalyst and the filtrate are obtained by solid-liquid separation; the catalyst can be recycled, and the filtrate is concentrated to obtain the pinacolone derivative 3-pentanone product. In an optional example of the present invention, the catalyst and the filtrate can be separated by means of pressure filtration, filtration or centrifugation. In an optional example of the present invention, activated carbon can be added after solid-liquid separation to further adsorb and separate the catalyst in the filtrate and remove the color, so as to enhance the effect of solid-liquid separation and the color and purity of the product. It should be noted that the present invention does not limit the specific operation of concentrating the filtrate, and those skilled in the art can select a method for separating the second solvent and the target product according to needs to obtain the 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone product, and the separated second solvent can be recycled.

[0030] Based on the above technical solution, the catalyst can be recycled at least 60 times. The examples of the present invention illustrate the technical effect that after the catalyst is recycled 60 times, the hydrogenation reaction of 1-(4-chlorophenyl)-4,4-dimethyl-1-ene-3-pentanone can still be efficiently catalyzed without adding a catalyst.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention uses stannous chloride / triphenylphosphine sulfide / palladium-carbon complex or stannous chloride / triphenylphosphine oxide / palladium-carbon complex as a catalyst to efficiently and highly selectively catalyze the hydrogenation of 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one to prepare 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone. This reaction has a high yield, a low content of dechlorination products, and a short reaction time. The catalyst used can be recycled with high activity, and there is no need to replenish the catalyst during the recycling process. The preparation process of the pinacolone derivative of the present invention reduces the consumption of palladium metal, greatly simplifies the process, saves production costs, and has important industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0033] Figure 1 Shows the liquid chromatogram of the concentrated 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone prepared in Example 4.5 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0034] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are given. However, it should be understood that these embodiments are only for more detailed description and should not be construed as limiting the present invention in any form, that is, it is not intended to limit the protection scope of the present invention.

[0035] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The test reagents used in the following embodiments are all conventional biochemical reagents unless otherwise specified; the experimental methods are all conventional methods unless otherwise specified.

[0036] The sources of the reagents in the following examples: 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one: Shanghai Hanhong Technology Co., Ltd., activated carbon: Shanghai Activated Carbon Factory Co., Ltd., methanol: Shaanxi Changqing Energy Chemical Co., Ltd., ethanol: Tianjin Fuyu Fine Chemical Co., Ltd., palladium-carbon: Wuhan Huaxiang Kejie Biotechnology Co., Ltd., triphenylphosphine oxide: Hubei Changyao Biotechnology Co., Ltd., triphenylphosphine sulfide: Shanghai Merck Chemical Technology Co., Ltd., stannous chloride: Shanghai Huayuan Century Trading Co., Ltd.

[0037] The present invention will be further described below in combination with exploration examples and embodiments.

[0038] EXPLORATION EXAMPLE

[0039] To solve the technical problems of excessive palladium-carbon reduction and product selectivity in the existing preparation process of pinacolone derivative 3-pentanone, the R & D team of the present invention conducted the following exploratory experiments.

[0040] Exploratory Example 1

[0041] First, the influence of the addition amount of a single palladium catalyst on the preparation process of pinacolone derivative 3-pentanone was explored. Taking the addition amount of palladium as 5% of the mass of raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one as an example, specifically, 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (50 kg, 224.5 mol) and 180 kg of methanol were put into a high-pressure reactor. After dissolution, 2.5 kg of palladium-carbon (content 10%) was added; nitrogen displacement was carried out twice, and then hydrogen displacement was carried out three times to fill the reaction system with hydrogen; the pressure was controlled at 1.5 MPa (hydrogen pressure maintained), and the temperature was raised to 65 °C ± 2 °C. Under these conditions, the reaction was carried out for about 8 h. When the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one ≤ 0.05% was detected, it was inferred that the reaction was completed; the reaction material after the reaction was cooled, nitrogen was used to displace hydrogen, and then pressure filtration was carried out. The obtained filtrate was added to the reactor, and then 2.5 kg of activated carbon was added, followed by filtration and concentration to obtain 48.8 kg of product with a purity of 97.4% and a yield of 96.8% (1.5% of dechlorinated reactants were generated).

[0042] This exploratory example tested the influence of different addition amounts of palladium as a single catalyst on the product purity, yield, content of other hydrogenation products, reaction time, etc. of the pinacolone derivative 3-pentanone process. The specific parameter control and effects are shown in Table 1.

[0043] Table 1

[0044]

[0045] It can be confirmed from Table 1 that when a single palladium catalyst is used in the preparation process of pinacolone derivative 3-pentanone, the yield of the reaction is between 94.6% and 98.9%; when the addition amount of catalyst palladium reaches 10% of the mass of reaction raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (Exploratory Example 1.1), although the reaction time is significantly shortened, there are more side reactions, and more dechlorinated products appear in the prepared product; when the addition amount of catalyst palladium is 2% - 5% of the mass of raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (Exploratory Examples 1.2 - 1.5), the time used is in the range of 8 - 15 h, and the generation amount of dechlorinated products decreases; when the amount of palladium-carbon catalyst used is further reduced to 0.5% - 1% (Exploratory Examples 1.6 - 1.7), not only does the reaction completion time extend, but the generation amount of dechlorinated products also increases.

[0046] Based on this exploration example, it can be seen that to reduce the generation of dechlorination by-products, the reaction time needs to be controlled within a certain range, and the length of the reaction time is related to the dosage of the palladium catalyst; moreover, when the dosage of the palladium catalyst is too high, it will also lead to an increase in the generation amount of dechlorination products.

[0047] Exploration Example 2

[0048] In order to reduce the generation of dechlorinated products in the preparation of pinacolone derivative 3-pentanone, the research team of the present invention further explored the influence of palladium catalysts in different forms on the preparation of pinacolone derivative 3-pentanone.

[0049] Specifically, 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (50 kg, 224.5 mol) and 180 kg of solvent methanol were put into a high-pressure reactor. After dissolution, a palladium catalyst with a mass of 5% of the mass of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one was added (the specific form of palladium is shown in Table 2); nitrogen replacement was carried out twice, and then hydrogen replacement was carried out three times to fill the reaction system with hydrogen, and the pressure was controlled at 2.5 - 4.5 MPa (hydrogen pressure maintained); the temperature was raised to 65°C ± 2°C, and the catalytic reaction was completed under this condition. When it was detected that the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one ≤ 0.05%, it was speculated that the reaction was completed; the reaction material was cooled, nitrogen was used to replace hydrogen, and pressure filtration was carried out. The obtained filtrate was added to the reactor, 2.5 kg of activated carbon was added, filtered, and concentrated to obtain the product.

[0050] In this exploration example, the research and development team of the present invention explored the product purity, yield, dechlorination product content, reaction time and other effects of the pinacolone derivative 3-pentanone process when other parameters and control conditions were the same and only the form of the catalyst was different. The specific control conditions and effect parameters are shown in Table 2.

[0051] Table 2

[0052]

[0053] It can be confirmed from Table 2 that under the catalytic action of palladium catalysts in different forms, the catalytic effects of both palladium salts and palladium hydrates are inferior to those of triphenylphosphine palladium or palladium complexes. Specifically, the purity and yield of Exploration Examples 2.6 - 2.11 are better than those of Exploration Examples 2.1 - 2.5, and the dechlorination product content is lower and the reaction end time is shorter; especially, the catalytic effects of stannous chloride / triphenylphosphine oxide palladium complex (Exploration Example 2.10) and stannous chloride / triphenylthiophosphine palladium complex (Exploration Example 2.11) are better.

[0054] Exploration Example 3

[0055] The R & D team of the present invention further explored the influence of the feeding mode of the catalyst on the preparation of pinacolone derivative 3-pentanone when using triphenylphosphine oxide-palladium complex or triphenylphosphine sulfide-palladium complex as the catalyst.

[0056] Specifically, taking the separate feeding of palladium-carbon and triphenylphosphine oxide or triphenylphosphine sulfide as an example, 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (50 kg, 224.5 mol) and 180 kg of solvent methanol were put into a high-pressure reactor. After dissolution, 2.0 kg of palladium-carbon (10 wt%) was first added, and the mass of palladium was 5% of the mass of the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one. Then triphenylphosphine oxide or triphenylphosphine sulfide was added; nitrogen replacement was carried out twice, and then hydrogen replacement was carried out three times to fill the reaction system with hydrogen, and the pressure was controlled at 1.5 MPa (hydrogen pressure maintained); the temperature was raised to 65 °C ± 2 °C, and the reaction was completed in 8 h under this condition. When the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one ≤ 0.05% was detected, it was speculated that the reaction was completed; the temperature of the reaction material was lowered, nitrogen was used to replace hydrogen, and pressure filtration was carried out. The obtained filtrate was added to the reactor, and then 2.5 kg of activated carbon was added, filtered, and concentrated to obtain the product. The catalyst feeding mode and catalytic effect parameters of this exploration example are shown in Table 3.

[0057] Table 3

[0058]

[0059] It can be confirmed from Table 3 that when using triphenylphosphine oxide-palladium-carbon complex or triphenylphosphine sulfide-palladium-carbon complex as the catalyst for the preparation of pinacolone derivative 3-pentanone, the catalytic effect of separate feeding (Exploration Examples 3.1 - 3.3) is not as good as that of directly introducing triphenylphosphine oxide / palladium-carbon complex and triphenylphosphine sulfide / palladium-carbon complex (Exploration Examples 3.4 - 3.6), which is manifested by the significantly higher content of dechlorination products in the product during separate feeding. In this exploration example, the catalytic effect of Exploration Examples 3.5 - 3.8 is the best. In addition, through recycling tests, the R & D team of the present invention found that when palladium-carbon and triphenylphosphine sulfide or triphenylphosphine oxide are fed separately, the catalytic activity of the catalyst palladium will gradually decrease with the increase of the number of cycles; while when fed in the form of triphenylphosphine sulfide / palladium-carbon complex or triphenylphosphine oxide / palladium-carbon complex, the form of the complex is stable, and the activity of the catalyst remains good during recycling and does not show a significant decrease with the increase of the number of cycles. The catalyst can be recycled and reused many times. Adding a small amount of stannous chloride makes the reaction effect more advantageous, and there are improvements not only in purity but also in reaction time. The catalytic effect of Exploration Examples 3.7 - 3.8 is the best.

[0060] In addition, the R & D team explored the preparation method of stannous chloride / triphenylphosphine oxide / palladium-carbon complex catalyst, and the specific operation is as follows: Add 100 kg of methanol solvent to the reaction flask, then add 14 g of stannous chloride and 2.78 kg of triphenylphosphine oxide, heat up and stir to dissolve, and then add 10.6 kg of palladium-carbon (10 wt%); the molar ratio of triphenylphosphine oxide to palladium is 1:1; under reflux conditions, stir for 3 - 5 h, cool down to room temperature and filter to obtain triphenylphosphine oxide / palladium-carbon complex. It should be noted that the complex product obtained by filtration is the stannous chloride / triphenylphosphine oxide / palladium-carbon complex catalyst. By adjusting the molar ratio of stannous chloride, triphenylphosphine oxide to palladium in palladium-carbon, triphenylphosphine oxide / palladium-carbon complex products with different ratios can be prepared.

[0061] The R & D team also explored the preparation method of stannous chloride / triphenylthiophosphine / palladium-carbon complex catalyst, and the specific operation is as follows: Add 80 kg of ethanol solvent to the reaction flask, then add 15 g of stannous chloride and 2.94 kg of triphenylthiophosphine, heat up and stir to dissolve; then add 10.6 kg of palladium-carbon (10 wt%); the molar ratio of triphenylthiophosphine to palladium is 1:1; under reflux conditions, stir for 3 - 5 h, cool down to room temperature and filter to obtain stannous chloride / triphenylthiophosphine / palladium-carbon complex. It should be noted that the complex product obtained by filtration is the stannous chloride / triphenylthiophosphine / palladium-carbon complex. By adjusting the molar ratio of stannous chloride, triphenylthiophosphine to palladium in palladium-carbon, triphenylphosphine oxide / palladium-carbon complex products with different ratios can be prepared.

[0062] Example 1

[0063] A preparation process of pinacolone derivative. Specifically, put 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (11.15 kg, 50 mol) and 50 kg of solvent methanol into a high-pressure reactor. After dissolution, add 334.5 g of stannous chloride / triphenylphosphine oxide / palladium-carbon complex (the molar ratio of triphenylphosphine oxide to palladium is 1:1), and the mass of palladium in this catalyst is 3% of the mass of the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one; displace with nitrogen twice, and then displace with hydrogen three times to make the reaction system filled with hydrogen, and control the pressure at 1.3 MPa (hydrogen pressure maintained); heat up to 60 °C ± 2 °C, and react for 4 h under this condition to complete the reaction. When the detection of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one ≤ 0.03% is speculated that the reaction is completed; cool down the reacted material, displace hydrogen with nitrogen, filter press (the filter cake is triphenylphosphine oxide / palladium-carbon complex, which can be recycled), add the obtained filtrate to the reactor, then add 1.5 kg of activated carbon, filter, and concentrate to obtain 22.3 kg of product with a purity of 99.2% and a yield of 99.4% (with 0.3% of dechlorination product).

[0064] Furthermore, in this embodiment, when other parameters and control conditions are the same and only the molar ratio of triphenylphosphine oxide to palladium in the catalyst is different, the effects on technical effects such as product purity, yield, production of dechlorinated products, and reaction time in the preparation process of the pinacolone derivative 3-pentanone are explored. The control conditions and effect parameters are shown in Table 4.

[0065] Table 4

[0066]

[0067]

[0068] It can be confirmed from the table that in the technical solution of the present invention, the molar ratio of triphenylphosphine oxide to palladium in the stannous chloride / triphenylphosphine oxide / palladium-carbon complex can be selected as (1-8):1; it can be seen from the above table that the product purity and yield of Examples 1.1-1.8 do not differ much, and from the content of the dechlorinated product, it can be verified that the molar ratio of triphenylphosphine oxide to palladium in the stannous chloride / triphenylphosphine oxide / palladium-carbon complex can be further selected as (3-6):1; in addition, it can also be confirmed from the reaction time that the molar ratio of triphenylphosphine oxide to palladium in the stannous chloride / triphenylphosphine oxide / palladium-carbon complex can be further selected as (3-4):1.

[0069] Example 2

[0070] A preparation process for a pinacolone derivative. Specifically, 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (11.15 kg, 50 mol) as the starting material and 50 kg of solvent methanol are put into a high-pressure reactor. After dissolution, 223 g of stannous chloride / triphenylthiophosphine / palladium-carbon complex is added, in which the molar ratio of triphenylthiophosphine to palladium is 1:1, the mass of palladium in the catalyst is 2% of the mass of the starting material, and the dosage of stannous chloride is 5% of the mass of triphenylthiophosphine; nitrogen replacement is carried out 2 times, and then hydrogen replacement is carried out 3 times to fill the reaction system with hydrogen, and the pressure is controlled at 1.0 MPa (hydrogen pressure maintained); the temperature is raised to 60°C ± 2°C, and the reaction is carried out for 4.5 h under this condition. When the detection of the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one ≤ 0.02% indicates that the reaction is completed. The reaction mixture is cooled, nitrogen is used to replace hydrogen, and pressure filtration is carried out (the filter cake obtained by filtration is stannous chloride / triphenylthiophosphine / palladium-carbon complex and can be recycled). The obtained filtrate is added to the reaction kettle, 1.5 kg of activated carbon is added, filtered, and concentrated to obtain 22.38 kg of product with a purity of 99.1% and a yield of 99.6% (the content of the dechlorinated product is 0.2%).

[0071] This example explored the effects on the technical effects such as the product purity, yield, content of dechlorination products, and reaction time of the preparation process of the pinacolone derivative 3-pentanone when other parameters and control conditions were the same and only the molar ratio of triphenylphosphine sulfide to palladium in the catalyst was different. The specific control conditions and effect parameters are shown in Table 5.

[0072] Table 5

[0073]

[0074] It can be verified from Table 5 that the molar ratio of triphenylphosphine sulfide to palladium in the stannous chloride / triphenylphosphine sulfide / palladium carbon complex in the inventive technical solution can be selected as (1-8):1. It can be seen from the above table that the difference in purity and yield during the reaction is not very large. It can be confirmed from the dechlorination products that the molar ratio of triphenylphosphine sulfide to palladium in the stannous chloride / triphenylphosphine sulfide / palladium carbon complex can be selected as (3-6):1, and further selected as (3-5):1 from the reaction time.

[0075] Example 3

[0076] A preparation process of a pinacolone derivative. Specifically, the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (22.3 kg, 100 mol) and 80 kg of the solvent methanol are put into a high-pressure reactor. After dissolution, a certain amount of stannous chloride / triphenylphosphine sulfide / palladium carbon complex (the molar ratio of triphenylphosphine sulfide to palladium is 4:1, and the dosage of stannous chloride is 5% of the mass of triphenylphosphine sulfide) is added. The mass of palladium in the catalyst is 0.05-5% of the mass of the starting material; nitrogen replacement is carried out 2 times, and then hydrogen replacement is carried out 3 times to make the reaction system full of hydrogen, and the pressure is controlled at 1.0 MPa (hydrogen pressure holding); the temperature is raised to 70°C ± 2°C, and the reaction is carried out under this condition. When the detection of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one ≤ 0.05% is inferred that the reaction is completed. The reaction mixture is cooled, nitrogen replaces hydrogen, and the filtrate obtained by pressure filtration (the filter cake obtained by filtration is the stannous chloride / triphenylphosphine sulfide / palladium carbon complex and can be recycled) is added to the reaction kettle, and then 3 kg of activated carbon is added, filtered, and concentrated to obtain the product.

[0077] This example explored the effects on the preparation process effect of the pinacolone derivative when other control parameters were the same and only the mass ratio of palladium in the catalyst to the mass of the starting material changed. The control conditions and effect parameters of this example are shown in Table 6.

[0078] Table 6

[0079]

[0080] As can be verified from Table 6, in the technical solution of the present invention, the mass of palladium in the catalyst can be selected as 0.05%-5% of the mass of the starting material, further preferably 0.5%-5%, still further preferably 1%-5%, still further preferably 1.5%-5%, and still further preferably 1.5%-3%.

[0081] Example 4

[0082] A preparation process of pinacolone derivatives. Specifically, put the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (22.3 kg, 100 mol) and 80 kg of solvent methanol into a high-pressure reactor. After dissolution, add a certain amount of stannous chloride / triphenylphosphine / palladium-carbon complex (the molar ratio of triphenylphosphine to palladium is 4:1, and the dosage of stannous chloride is 5% of the mass of triphenylphosphine). The mass of palladium in the catalyst is 0.05-5% of the mass of the starting material respectively; displace with nitrogen twice, and then displace with hydrogen three times to fill the reaction system with hydrogen, and control the pressure at 1.0 MPa (hydrogen pressure holding); raise the temperature to 70°C ± 2°C, and complete the reaction under this condition. When the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one ≤ 0.05%, it is speculated that the reaction is completed. Cool down the reaction material, displace hydrogen with nitrogen, and filter press (the filter cake obtained by filtration is stannous chloride / triphenylphosphine / palladium-carbon complex, which can be recycled). Add 3 kg of activated carbon to the filtrate obtained and filter it, and concentrate to obtain the product.

[0083] In this example, when other control parameters are the same and only the mass ratio of palladium in the catalyst to the mass of the starting material changes, the influence on the preparation process effect of pinacolone derivatives is explored. The control conditions and effect parameters of this example are shown in Table 7.

[0084] Table 7

[0085]

[0086] As can be verified from Table 7, in the technical solution of the present invention, the mass of palladium in the catalyst can be selected as 0.05%-5% of the mass of the starting material, further preferably 1%-5%, still further preferably 1%-5%, still further preferably 1.5%-5%, and still further preferably 1.5%-3%.

[0087] Example 5

[0088] A preparation process of pinacolone derivatives. Specifically, the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (22.3 kg, 100 mol) and 100 kg of solvent ethanol are put into a high-pressure reactor. After dissolution, 334.5 g of stannous chloride / triphenylphosphine / palladium carbon complex (the molar ratio of triphenylphosphine to palladium is 4:1, and the dosage of stannous chloride is 5% of the mass of triphenylphosphine) is added. The mass of palladium in the catalyst is 1.5% of the mass of the starting material. After purging with nitrogen twice, then purging with hydrogen three times, the reaction system is filled with hydrogen, and the pressure is controlled at 1.0 MPa (hydrogen pressure maintained). The temperature is controlled to change from 60 to 90 °C. Under this condition, the catalytic reaction is carried out. When the content of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one is ≤ 0.05%, it is speculated that the reaction is completed. The reaction material after the reaction is cooled, nitrogen is used to displace hydrogen, and the filtrate obtained by pressure filtration (the filter cake obtained by filtration is stannous chloride / triphenylphosphine / palladium carbon complex and can be recycled) is added to the reactor, then 5 kg of activated carbon is added, filtered, and concentrated to obtain the product.

[0089] In this example, when other parameters and control conditions are the same and only the reaction temperature used is different, the effects on the product purity, yield, dechlorination product, and reaction time of the preparation process of the catalyzed pinacolone derivative 3-pentanone are explored. The control conditions and effect parameters are shown in Table 8.

[0090] Table 8

[0091]

[0092] It can be verified from Table 8 that the reaction temperature of the preparation process of the pinacolone derivative of the present invention can be selected from 50 to 90 °C, further preferably 60 to 90 °C, still further preferably 60 to 70 °C, and most preferably 70 °C.

[0093] Example 6

[0094] A preparation process of pinacolone derivatives. Specifically, the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (22.3 kg, 100 mol) and 100 kg of the solvent methanol are put into a high-pressure reactor. After dissolution, 669 g of stannous chloride / triphenylphosphine oxide / palladium carbon complex (the molar ratio of triphenylphosphine oxide to palladium is 4:1, and the dosage of stannous chloride is 5% of the mass of triphenylphosphine oxide) is added. The mass of palladium in the catalyst is 3% of the mass of the starting material. After purging with nitrogen twice, then purging with hydrogen three times, the reaction system is filled with hydrogen, and the pressure is controlled at 1.0 MPa (hydrogen pressure maintained). The temperature is controlled to change from 60 to 90 °C. Under this condition, the catalytic reaction is carried out. When the content of the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one is ≤ 0.05%, it is speculated that the reaction is completed. The reaction mixture is cooled, the hydrogen is purged with nitrogen, and the filtrate obtained by pressure filtration (the filter cake obtained by filtration is stannous chloride / triphenylphosphine oxide / palladium carbon complex and can be recycled) is added to the reactor, and then 5 kg of activated carbon is added, followed by filtration and concentration to obtain the product.

[0095] In this example, the effects on the product purity, yield, dechlorination product, and reaction time of the preparation process of the catalyzed pinacolone derivative 3-pentanone were explored when other parameters and control conditions were the same and only the reaction temperature used was different. The control conditions and effect parameters are shown in Table 9.

[0096] Table 9

[0097]

[0098] It can be verified from Table 9 that the reaction temperature of the preparation process of the pinacolone derivative of the present invention can be selected from 50 to 90 °C, further preferably from 60 to 90 °C, still further preferably from 60 to 70 °C, and most preferably 70 °C.

[0099] Example 7

[0100] A preparation process of pinacolone derivatives. Specifically, charge the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (22.3 kg, 100 mol) and 100 kg of solvent ethanol into a high-pressure reactor. After dissolution, add 334.5 g of stannous chloride / triphenylphosphine / palladium carbon complex (the molar ratio of triphenylphosphine to palladium is 4:1, and the dosage of stannous chloride is 5% of the mass of triphenylphosphine). The mass of palladium in the catalyst is 1.5% of the mass of the starting material. Replace the gas with nitrogen twice, and then replace it with hydrogen three times to fill the reaction system with hydrogen, and control the pressure at 0.4 - 1.3 MPa (hydrogen pressure holding). Control the temperature at 70 °C. Under this condition, when the catalytic reaction is completed, detect that the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one ≤ 0.05% to presume that the reaction is completed. Cool down the reaction material, replace hydrogen with nitrogen, and filter press (the filter cake obtained by filtration is stannous chloride / triphenylphosphine / palladium carbon complex, which can be recycled). Add the obtained filtrate to the reactor, then add 5.0 kg of activated carbon, filter, and concentrate to obtain the product.

[0101] In this example, the effects on the product purity, yield, dechlorination product, and reaction time of the preparation process of pinacolone derivatives 3-pentanone were explored when other parameters and control conditions were the same and only the reaction pressure used was different. The control conditions and effect parameters are shown in Table 10.

[0102] Table 10

[0103]

[0104] It can be confirmed from Table 10 that the reaction pressure in the preparation process of the pinacolone derivatives of the present invention can be selected as 0.4 - 1.3 MPa, further preferably 0.6 - 1.3 MPa, still further preferably 0.7 - 1.3 MPa, and even further preferably 0.9 - 1.3 MPa.

[0105] Example 8

[0106] A preparation process of pinacolone derivatives. Specifically, put the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (22.3 kg, 100 mol) and 100 kg of solvent ethanol into a high-pressure reactor. After dissolution, add 669 g of stannous chloride / triphenylphosphine / palladium-carbon complex (the molar ratio of triphenylphosphine to palladium is 4:1, and the dosage of stannous chloride is 5% of the mass of triphenylphosphine). The mass of palladium in the catalyst is 3% of the mass of the starting material. Replace with nitrogen twice, and then replace with hydrogen three times to fill the reaction system with hydrogen, and control the pressure at 0.4 - 1.3 MPa (hydrogen pressure holding); control the temperature at 70 °C. Under this condition, the catalytic reaction is completed, and when the detection of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one ≤ 0.05%, it is presumed that the reaction is completed. Cool down the reaction material, replace hydrogen with nitrogen, and filter press (the filter cake obtained by filtration is stannous chloride / triphenylphosphine / palladium-carbon complex and can be recycled). Add the obtained filtrate to the reactor, then add 5.0 kg of activated carbon, filter, and concentrate to obtain the product.

[0107] In this example, when other parameters and control conditions are the same and only the reaction pressure used is different, the effects on the product purity, yield, dechlorination product, and reaction time of the preparation process of pinacolone derivatives 3-pentanone are explored. The control conditions and effect parameters are shown in Table 11.

[0108] Table 11

[0109]

[0110] It can be confirmed from Table 11 that the reaction pressure in the preparation process of the pinacolone derivatives of the present invention can be selected as 0.7 - 1.3 MPa, and further preferably 0.9 - 1.3 MPa.

[0111] Example 9

[0112] A process for preparing pinacolone derivatives. Specifically, the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (22.3 kg, 100 mol) and 100 kg of the solvent methanol are charged into a high-pressure reactor. After dissolution, 669 g of stannous chloride / triphenylphosphine oxide / palladium carbon complex (the molar ratio of triphenylphosphine oxide to palladium is 4:1, and the dosage of stannous chloride is 5% of the mass of triphenylphosphine oxide) is added, and the mass of palladium is 3% of the mass of the starting material. After purging with nitrogen twice, then purging with hydrogen three times, the reaction system is filled with hydrogen, and the pressure is controlled at 0.9 MPa (hydrogen pressure maintained). The temperature is controlled to change within 70 ± 1 °C. Under these conditions, the reaction is completed. When the content of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one is ≤ 0.05%, it is speculated that the reaction is completed. The reaction mixture is cooled, the hydrogen is purged with nitrogen, and the filtrate obtained by pressure filtration (the filter cake obtained by filtration is stannous chloride / triphenylphosphine oxide / palladium carbon complex, which can be recycled) is added to the reactor, and then 5 kg of activated carbon is added. After filtration and concentration, 22.38 kg of a colorless oily product is obtained, with a purity of 99.5% and a yield of 99.4%, and the content of the dechlorinated compound is < 0.02%.

[0113] In this example, the stannous chloride / triphenylphosphine oxide / palladium carbon complex obtained by filtration is recycled. Experiments have confirmed that when recycled for the 60th time, 22.31 kg of a colorless oily product can be catalytically obtained, with a purity of 99.4% and a yield of 99.3%, and the content of the dechlorinated compound is < 0.02%. It can be seen that during the recycling process, the activity of the catalyst of the present invention does not gradually decrease with the increase in the number of recycling times. The selectivity of the catalyst recycling is high, and high-purity products can be obtained in high yields, and the content of by-products is reduced, thus reducing the difficulty of the post-treatment process. Therefore, the process for preparing pinacolone derivatives of the present invention can achieve high-activity recycling of the catalyst and has important economic value.

[0114] Example 10

[0115] A preparation process of pinacolone derivatives. Specifically, put the starting material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one (22.3 kg, 100 mol) and 100 kg of solvent ethanol into a high-pressure reactor. After dissolution, add 669 g of stannous chloride / triphenylphosphine / palladium carbon complex (the molar ratio of triphenylphosphine to palladium is 4:1, and the dosage of stannous chloride is 5% of the mass of triphenylphosphine). The mass of palladium is 3% of the mass of the starting material. Replace with nitrogen twice, and then replace with hydrogen three times to fill the reaction system with hydrogen, and control the pressure at 0.9 MPa (hydrogen pressure maintenance); control the temperature change at 70 ± 1 °C. Under this condition, the reaction is completed. When the detection of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-penten-3-one ≤ 0.05%, it is speculated that the reaction is completed. Cool down the reaction material, replace hydrogen with nitrogen, and filter press (the filter cake obtained by filtration is stannous chloride / triphenylphosphine / palladium carbon complex, which can be recycled). The obtained filtrate is added to the reaction kettle, and then 4.5 kg of activated carbon is added, filtered, and concentrated to obtain 22.43 kg of a colorless oily product with a purity of 99.6% and a yield of 99.8%, and the dechlorinated compound < 0.02%.

[0116] In this example, the stannous chloride / triphenylphosphine / palladium carbon complex obtained by filtration is recycled. Experiments confirm that when recycled for the 60th time, 22.40 kg of a colorless oily product can be catalytically obtained with a purity of 99.5% and a yield of 99.5%, and the dechlorinated compound < 0.02%. It can be seen that during the recycling process, the activity of the catalyst of the present invention does not gradually decrease with the increase in the number of recycling times. The selectivity of the catalyst recycling is high, and high-purity products can be obtained with high yields, and the content of by-products is reduced, thus reducing the difficulty of the post-treatment process. Therefore, the preparation process of pinacolone derivatives of the present invention can achieve high-activity recycling of the catalyst, which has important economic value.

[0117] Example 11

[0118] This example shows an actual production condition of the preparation process of pinacolone derivatives of the present invention. It should be noted that this example is only a better display and does not limit the protection scope of the present invention. Specifically, in the factory of the applicant of the present invention, when carrying out the actual production of 1000 tons per year of 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone, a complex catalyst (stannous chloride / triphenylphosphine oxide / palladium carbon complex or stannous chloride / triphenylphosphine / palladium carbon complex) is added to the reactor. The application of the complex catalyst improves the selectivity of the reaction, the reaction yield is increased, and high-quality products can be obtained; in addition, in the actual process, the discharge of wastewater in the original production process is also changed, saving about more than 5 million yuan in environmental protection treatment costs per year.

[0119] It should be noted that the above content is a further detailed description of the present invention in combination with specific implementation manners, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention pertains, without departing from the concept of the present invention, several simple improvements can still be made, and all should be regarded as belonging to the scope of protection of the present invention.

Claims

1. A process for preparing a pinacolone derivative, characterized in that: include: The raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-ene-3-pentanone undergoes a hydrogenation reaction with H2 in the presence of a catalyst to obtain 1-(4-chlorophenyl)-4,4-dimethyl-3-pentanone; wherein the catalyst is stannous chloride / triphenylphosphine sulfide / palladium-carbon complex, or stannous chloride / triphenylphosphine oxide / palladium-carbon complex.

2. The process for preparing a pinacolone derivative according to claim 1, characterized in that: When the catalyst is stannous chloride / triphenylphosphine sulfide / palladium-carbon complex, the molar ratio of triphenylphosphine sulfide to palladium in palladium-carbon is (3-8):1, preferably (3-6):1, and further preferably (3-5):1; when the catalyst is stannous chloride / triphenylphosphine oxide / palladium-carbon complex, the molar ratio of triphenylphosphine oxide to palladium in palladium-carbon is (3-8):1, preferably (3-6):1, and further preferably (3-4):

1.

3. The process for preparing a pinacolone derivative according to claim 1 or 2, characterized in that: The amount of stannous chloride used is 0.3-1% of the mass of triphenyl sulfide or triphenyl phosphine oxide, preferably 5%.

4. The process for preparing a pinacolone derivative according to claim 1, characterized in that: The preparation method of the catalyst comprises: coordinating and complexing palladium carbon with stannous chloride / triphenylphosphine sulfide, or palladium carbon with stannous chloride / triphenylphosphine oxide in a first solvent to obtain the catalyst; Preferably, the first solvent comprises at least one of methanol or ethanol; Preferably, the loading amount of palladium in the palladium carbon is 5wt% to 10wt%.

5. The process for preparing a pinacolone derivative according to claim 1, characterized in that: The mass of palladium in the catalyst is 0.05% to 5% of the mass of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-ene-3-pentanone, preferably 1% to 5%, and more preferably 1.5% to 3%.

6. The process for preparing a pinacolone derivative according to claim 1, characterized in that: The temperature of the hydrogenation reaction is 50-90°C, preferably 60-90°C, and more preferably 60-70°C.

7. The process for preparing a pinacolone derivative according to claim 1, characterized in that: When the catalyst is stannous chloride / triphenylphosphine sulfide / palladium carbon complex, the pressure of the hydrogenation reaction is 0.4-1.3 MPa, preferably 0.6-1.3 MPa, and further preferably 0.9-1.3 MPa; when the catalyst is stannous chloride / triphenylphosphine oxide / palladium carbon complex, the pressure of the hydrogenation reaction is 0.7-1.3 MPa, preferably 0.9-1.3 MPa.

8. The process for preparing a pinacolone derivative according to claim 1, characterized in that: The hydrogenation reaction is carried out in a second solvent, wherein the second solvent comprises at least one of methanol or ethanol; Preferably, the amount of the second solvent used is 1 to 10 times the mass of the raw material 1-(4-chlorophenyl)-4,4-dimethyl-1-ene-3-pentanone.

9. The process for preparing a pinacolone derivative according to claim 1, characterized in that: The method also includes a post-processing step: the materials after the reaction are cooled and decompressed, and then solid-liquid separation is performed to obtain a catalyst and a filtrate; the catalyst can be recycled, and the filtrate is concentrated to obtain the pinacolone derivative 3-pentanone product.

10. The process for preparing a pinacolone derivative according to claim 9, characterized in that: The catalyst can be recycled at least 60 times.

Images