A preparation method of 4-oxoisophorone

Abstract

The present invention discloses a preparation method of 4-oxoisophorone. This method prepares 4-oxoisophorone by oxidizing β-isophorone, and respectively provides a reaction phase chamber for accommodating the reaction system, a gas phase chamber for caching the mixed gas and communicating with the reaction phase chamber, and a connection channel for connecting the lower part of the reaction phase chamber with the gas phase chamber. The gas phase chamber, the connection channel and the reaction phase chamber form a gas circulation channel; the reaction system includes an organic base, a catalytic system and β-isophorone, the catalytic system includes copper ions, an acid and water, and the mixed gas includes oxygen; during the oxidation process, the mixed gas enters the reaction system from the lower part of the reaction phase chamber through the connection channel, part or all of the oxygen participates in the reaction, and the gas that does not participate in the reaction returns to the gas phase chamber, and new oxygen is supplemented to the gas phase chamber to control its pressure at a preset value; on the basis of having a high conversion rate and selectivity, the present invention has no tail gas emission during the preparation process and is simple to operate.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and particularly relates to a preparation method of 4-oxoisophorone. Background Art

[0002] 4-Oxoisophorone (also known as tea ketone, abbreviated as KIP) is an important chemical intermediate. Currently, the most commonly used preparation method is to use β-isophorone as a raw material, and in the presence of a catalyst, it is oxidized by oxygen, a gas mixture containing oxygen, or hydrogen peroxide to produce 4-oxoisophorone. The reaction formula is as follows:

[0003]

[0004] However, it is found in practice that the above process still has the following problems:

[0005] 1. When oxidizing with oxygen or a gas mixture containing oxygen, such as CN113429271A and CN1865210A, it is necessary to continuously introduce a large amount of oxygen or gas mixture, resulting in a large amount of tail gas generation, and it is easy to carry out organic substances during the process of discharging the tail gas, thereby corroding the equipment or polluting the environment, etc.;

[0006] 2. When oxidizing with hydrogen peroxide, such as CN111777497B and CN108440262B, on the one hand, there are obvious safety problems in the storage and transportation of hydrogen peroxide. On the other hand, it is basically necessary to add an aqueous hydrogen peroxide solution (i.e., hydrogen peroxide) dropwise, which is likely to cause a phenomenon of too high local concentration and is not conducive to industrial application;

[0007] 3. The supporting catalyst is not easy to obtain and the preparation is complex, such as CN1100075894B, CN111269949B, CN108440262B, etc. Summary of the Invention

[0008] The object of the present invention is to overcome one or more deficiencies in the prior art, and provide an improved preparation method of 4-oxoisophorone that has a high conversion rate and selectivity and has no tail gas emission during the preparation process.

[0009] To achieve the above object, the technical solution adopted by the present invention is: a preparation method of 4-oxoisophorone, which prepares 4-oxoisophorone by oxidizing β-isophorone, wherein:

[0010] A reaction phase chamber for accommodating the reaction system, a gas phase chamber for caching the gas mixture and communicating with the reaction phase chamber, and a connection channel for connecting the lower part of the reaction phase chamber with the gas phase chamber are respectively provided;

[0011] The reaction system comprises an organic base, a catalytic system and β-isophorone, and the catalytic system comprises copper ions, an acid and water;

[0012] The mixed gas comprises oxygen; in terms of volume percentage, the content of oxygen in the mixed gas is 2%-15%;

[0013] During the oxidation of β-isophorone, the mixed gas enters the reaction system from the lower part of the reaction phase chamber through the connection channel, and part or all of the oxygen participates in the reaction. The gas that does not participate in the reaction returns to the gas phase chamber, and new oxygen is supplemented into the gas phase chamber to control the pressure in the gas phase chamber at a preset value.

[0014] In some embodiments of the present invention, the mixed gas further comprises a blending gas, and the blending gas can be nitrogen, argon, etc.

[0015] In some embodiments of the present invention, the gas phase chamber, the connection channel and the reaction phase chamber form a gas circulation channel.

[0016] According to some preferred and specific aspects of the present invention, the catalytic system is formed by dispersing a copper salt, an organic acid and / or an inorganic acid in water.

[0017] According to some preferred aspects of the present invention, the copper salt is a combination of one or more selected from copper acetate, copper nitrate, copper sulfate, and copper chloride.

[0018] According to some preferred aspects of the present invention, the organic acid and / or inorganic acid is a combination of one or more selected from acetic acid, sulfuric acid, hydrochloric acid, and nitric acid.

[0019] According to a specific aspect of the present invention, the catalytic system comprises copper acetate, acetic acid and water.

[0020] According to a specific aspect of the present invention, the catalytic system comprises copper acetate, nitric acid and water.

[0021] According to a specific aspect of the present invention, the catalytic system comprises copper acetate, hydrochloric acid and water.

[0022] According to a specific aspect of the present invention, the catalytic system comprises copper sulfate, acetic acid and water.

[0023] According to some preferred aspects of the present invention, in terms of mass percentage, in the catalytic system, the content of the copper salt is 0.1%-2.0%, and the content of the organic acid and / or inorganic acid is 10%-50%.

[0024] In some embodiments of the present invention, in terms of mass percentage, the content of the copper salt in the catalytic system includes but is not limited to 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, 2.0%, etc.

[0025] In some embodiments of the present invention, in terms of mass percentage, the content of the organic acid and / or inorganic acid in the catalytic system includes but is not limited to 10%, 12%, 15%, 16%, 18%, 20%, 21%, 22%, 24%, 25%, 26%, 28%, 30%, 32%, 33%, 35%, 36%, 38%, 40%, 41%, 42%, 43%, 45%, 48%, 50%, etc.

[0026] In some embodiments of the present invention, in terms of mass percentage, the content of the copper salt in the catalytic system is 0.4% - 1.2%, and the content of the organic acid and / or inorganic acid is 12% - 35%.

[0027] According to some preferred aspects of the present invention, the feeding mass ratio of the catalytic system to β - isophorone is 0.01 - 0.05∶1.

[0028] According to some preferred aspects of the present invention, both ends of the connecting channel are respectively communicated with the bottom of the lower part of the reaction phase chamber and the upper part of the gas phase chamber.

[0029] According to some preferred aspects of the present invention, an oxygen inlet is provided at the upper part of the gas phase chamber, and the oxygen inlet and the connection part of the gas phase chamber communicating with the connecting channel are respectively located on opposite sides of the gas phase chamber.

[0030] According to some preferred aspects of the present invention, the process of oxidizing β - isophorone is realized by means of a reaction vessel formed with a cavity, and the reaction phase chamber and the gas phase chamber are integrally formed to constitute the cavity.

[0031] According to some preferred aspects of the present invention, a shearing mechanism is provided at the bottom inside the reaction phase chamber. The center line of the shearing mechanism coincides with the center line of the reaction phase chamber, and the air inlet for introducing the mixed gas on the reaction phase chamber is directly opposite to the shearing mechanism. The above settings can enable the mixed gas to be strongly dispersed by the shearing mechanism together with the reaction system rapidly when entering the reaction system, and can be thrown in all directions and collide with each other under the high - speed drive of the shearing mechanism, achieving the purpose of rapidly dispersing the liquid flow and the gas flow together. And since the amount of the liquid flow in the reaction system is much larger than the flow rate of the oxygen in the just - introduced mixed gas, the purpose of rapidly and uniformly dispersing the oxygen in the liquid phase is realized.

[0032] In some embodiments of the present invention, the shearing mechanism preferably adopts a mechanism with strong dispersion and mixing capabilities, such as a stator-rotor shearing mechanism, etc.

[0033] According to some preferred aspects of the present invention, a controller for controlling the flow rate of the mixed gas is provided on the connection channel. The controller includes, but is not limited to, a pressure blower. The gas amount of the mixed gas in the gas phase chamber entering the reaction phase chamber through the connection channel can be controlled by the variable-frequency motor of the pressure blower, increasing the means for controlling the reaction rate; when the volume of the reaction phase chamber is very large, the air volume can be adjusted to the most suitable state for the reaction by adjusting the air volume of the pressure blower. Of course, in some other embodiments, other control components capable of actively adjusting the flow rate of the mixed gas can be selected.

[0034] According to some preferred aspects of the present invention, the pressure preset value is 100 - 3000 Pa gauge pressure.

[0035] According to some preferred aspects of the present invention, the organic base is a combination of one or more selected from pyridine, 2-methylpyridine, 3-methylpyridine, and 4-methylpyridine. These pyridine-based organic bases can provide a suitable alkaline environment, which is beneficial to the progress of the reaction.

[0036] According to some preferred aspects of the present invention, the feeding mass ratio of the organic base to the β-isophorone is 0.5 - 2.5∶1, ensuring a suitable alkaline environment for the oxidation reaction, reducing the concentration of β-isophorone, and reducing the number of by-products of multi-molecular binding of β-isophorone.

[0037] According to some preferred aspects of the present invention, during the oxidation of β-isophorone, the reaction temperature is controlled at 30 - 50 °C.

[0038] Different from the prior art of directly introducing oxygen or air into the reaction system, the present invention introduces new oxygen into the gas phase chamber to mix with the residual gas in the space (only a small amount of oxygen, or even no oxygen, mostly other mixed gases such as nitrogen). A "poor oxygen" type mixed gas is obtained. The "poor oxygen" type mixed gas enters the reaction system from the lower part of the reaction phase chamber through the connection channel. The remaining gas of the "poor oxygen" type mixed gas that has consumed part or all of the oxygen is re-enriched into the gas phase chamber. In this way, first, the purpose of poor oxygen oxidation can be achieved without supplementing mixed gas such as nitrogen from the outside; second, there is no need to discharge the accumulated mixed gas. When the reaction system discharges the accumulated gas, it is easy to carry out some substances out of the reaction system, making the reaction process very unstable; third, the operation is convenient. During the reaction process, only an appropriate amount of oxygen needs to be supplemented in a timely manner according to the change of the pressure value until the set pressure preset value is reached, without excessive intervention in the reaction process.

[0039] According to the present invention, practice shows that: (1) in the presence of an organic base, an acid, and copper ions, water and oxygen can form a trace amount of hydrogen peroxide (the peroxide value can be detected by an instrument. Experimental process: charge metered pyridine, copper acetate, acetic acid, and water into a flask, stir evenly, take a sample, then continuously charge a "poor oxygen" mixed gas with an oxygen content of 15% into the reaction flask for several hours, and then take a sample to detect the peroxide value together with the sample before charging the gas. The results show that the peroxide value of the sample before charging the mixed gas is 0, and the peroxide value of the sample after charging the gas can reach 0.17, with the unit being the milligrams of 0.01 mol / L sodium thiosulfate solution consumed per gram of the sample). Hydrogen peroxide can oxidize β-isophorone to prepare 4-oxoisophorone, and then turn into water again. Thus, a dynamic equilibrium is formed, where hydrogen peroxide can be generated while maintaining the basic stability of the amount of water in the system. Therefore, when the oxygen supply is constant, the concentration of newly generated hydrogen peroxide in the system is also relatively stable, enabling the oxidation process driven by hydrogen peroxide to proceed stably. Of course, in the system, there may also be a process of directly oxidizing β-isophorone by oxygen to prepare 4-oxoisophorone. Therefore, when the oxygen supply is constant, the oxidation process of the present invention is within a controllable range, avoiding the situation where sudden fluctuations in the concentrations of various components easily form by-products. In addition, by such a way that the formation and consumption of hydrogen peroxide occur synchronously, it also avoids the drawbacks of the existing technology, such as the single or batch addition (e.g., dropping) of hydrogen peroxide, which easily forms a concentration gradient in the system and causes an increase in the selectivity of by-products.

[0040] (2) The acid can combine with the organic base to form a salt, which has an obvious effect on controlling the alkalinity or nucleophilicity of the reaction system.

[0041] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0042] The method of the present invention solves the problem of generating a large amount of tail gas when oxidizing β-isophorone to prepare 4-oxoisophorone by introducing an oxidizing gas in the prior art. At the same time, it is characterized in that the system basically does not need to discharge tail gas to the outside, reducing the system fluctuation caused by the loss of substances in the reaction system. As a result, the substances that directly or indirectly play a role in catalytic oxidation and other processes in the reaction process maintain a basically stable concentration, and the situation where the concentration gradient of each component in the reaction system appears due to the entry and exit of substances will not occur, which is conducive to curbing the occurrence of side reactions and improving the selectivity of the target product. In addition, the method of the present invention is simple to operate, and the oxygen content in the reaction system can always be within a controllable range, with high safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic structural diagram of the reaction vessel adopted in the embodiment of the present invention;

[0044] Among the attached drawing reference numerals, 1 is the reaction phase chamber; 2 is the gas phase chamber; 3 is the connection channel; 4 is the oxygen inlet pipe; 5 is the shearing mechanism; 6 is the β-isophorone feed pipe; 7 is the organic base feed pipe; 8 is the catalyst system feed pipe; 9 is the jacket.

[0045] Figure 2 This is the gas chromatogram of the product obtained in Example 1 of the present invention. Detailed implementation manners

[0046] As Figure 1 shown, the present invention can adopt the reaction vessel shown in Figure 1 for the oxidation reaction. The reaction vessel includes a main body with a cavity, a connection channel 3, an oxygen inlet pipe 4, a shearing mechanism 5, a β-isophorone feed pipe 6, an organic base feed pipe 7, a catalyst system feed pipe 8, a jacket 9, a blending gas input pipe (not shown), a pressure blower (not shown), and a vent valve (not marked);

[0047] Among them, the cavity is integrally formed by a gas phase chamber 2 and a reaction phase chamber 1 which are arranged in the vertical direction and communicate with each other. When feeding materials, the materials will fall from the gas phase chamber 2 into the reaction phase chamber 1. An oxygen inlet is provided on the main body, and the oxygen inlet is communicated with the oxygen inlet pipe 4. The connection parts of the oxygen inlet and the gas phase chamber 2 with the connection channel 3 are respectively located on opposite sides of the gas phase chamber 2; the β-isophorone feed pipe 6 and the organic base feed pipe 7 are respectively communicated with the upper part of the main body. Further, both ends of the connection channel 3 are respectively communicated with the bottom of the lower part of the reaction phase chamber 2 and the upper part of the gas phase chamber 2. The gas phase chamber 2, the connection channel 3 and the reaction phase chamber 1 form a gas circulation channel. The connection channel 3 and the catalyst system feed pipe 8 share a section of pipeline to communicate with the main body. A pressure blower (not shown) is arranged on the connection channel 3 to control the flow rate of the mixed gas; the blending gas input pipe and the vent valve are respectively communicated with the upper part of the gas phase chamber 2. The vent valve can be used to discharge the internal gas or discharge the gas to be replaced during gas replacement;

[0048] The shearing mechanism 5 has a part extending into the reaction phase chamber 1. The air inlet on the reaction phase chamber 1 for introducing the mixed gas is directly opposite to this part of the structure of the shearing mechanism 5. This part of the structure can enable the mixed gas to be strongly dispersed quickly with the reaction system when entering the reaction system, and can be thrown in all directions and collide with each other under the high-speed drive of the shearing mechanism, achieving the purpose of quickly and evenly dispersing the liquid flow and the gas flow together. And because the amount of the liquid flow in the reaction system is much larger than the flow rate of the oxygen in the just-introduced mixed gas, the purpose of quickly and evenly dispersing the oxygen in the liquid phase is realized;

[0049] The jacket 9 is covered on the outside of the main body, and its function is to control the internal temperature, for example, heating and cooling can be respectively achieved by introducing a heat source or a cold source.

[0050] When actually operating, the operation process is as follows: the catalytic system can be prepared first and then β-isophorone and an organic base are added to the reaction phase chamber of the reaction vessel, and then the prepared catalytic system is added, and the internal temperature of the reaction vessel is controlled at a preset temperature (30-50° C.) by passing hot water into the jacket, the shear mechanism is turned on, and the rotation speed is set (1000-2900 rpm);

[0051] (Method 1) When the reaction starts, if the air in the gas phase chamber itself is not replaced, a mixed gas such as nitrogen can be added through the mixed gas input pipe, and the amount of nitrogen added and the air volume of the pressure fan are controlled to control the pressure in the gas phase chamber to a preset pressure value (gauge pressure 100-3000Pa). The pressure fan drives the mixed gas to flow from the reaction system, and the oxygen is partially or completely consumed. The remaining gas returns to the gas phase chamber and is mixed with the newly added nitrogen to circulate again. When it is detected that the oxygen concentration in the gas phase chamber is reduced to a volume percentage of 2%-15%, the nitrogen is stopped and the oxygen inlet pipe is opened. The mixed gas is continued to flow from the reaction system through the pressure fan, and the process is repeated. In this process, the oxygen input value of the oxygen inlet pipe and the air volume of the pressure fan are respectively controlled to control the pressure in the gas phase chamber to a preset pressure value (gauge pressure 100-3000Pa); or,

[0052] (Method 2) When the reaction starts, there is air in the gas phase chamber itself, and part of the air in the gas phase chamber can be replaced by the mixed gas input pipe (the replaced part of the air can be discharged through the exhaust valve, and the exhaust valve can be closed after the replacement is completed), until it is detected that the oxygen content is reduced to 2%-15% by volume, the nitrogen is stopped and the oxygen inlet pipe is opened, and the pressure blower is started to make the mixed gas in the gas phase chamber start to circulate in the reaction system, the oxygen is partially or completely consumed, and the remaining gas returns to the gas phase chamber and is mixed with the oxygen supplemented from the oxygen inlet pipe. The process is circulated, and in this process, the oxygen input value of the oxygen inlet pipe and the air volume of the pressure blower are respectively controlled to control the pressure in the gas phase chamber to the preset pressure value (gauge pressure 100-3000Pa); or,

[0053] (Mode 3) When the reaction starts, there is air in the gas phase chamber itself. The air in the gas phase chamber is displaced by a mixed gas pipe (a combination of oxygen and a blending gas such as nitrogen, with the volume percentage of oxygen being 2%-15%). The displaced air can be discharged through an evacuation valve, and the evacuation valve can be closed after the displacement is completed. After multiple displacements, the supply of the mixed gas is stopped, the oxygen inlet pipe is opened, and the pressure blower is started to make the mixed gas in the gas phase chamber start to circulate in the reaction system. The oxygen is partially or completely consumed, and the remaining gas returns to the gas phase chamber and mixes with the oxygen replenished from the oxygen inlet pipe. This process is cycled. During this process, the oxygen input value of the oxygen inlet pipe and the air volume of the pressure blower are respectively controlled to control the pressure in the gas phase chamber to a preset pressure value (gauge pressure 100-3000 Pa);

[0054] Control the oxidation time. When the oxidation reaction is completed, transfer the oxidation reaction solution to a recovery kettle, recover the organic base under reduced pressure. After the recovery of the organic base is completed, transfer the concentrated solution in the recovery kettle to a wiped film evaporator for weight reduction. After weight reduction, 4-oxoisophorone is obtained.

[0055] During the implementation process of the present invention, according to Dalton's law of partial pressures and Amagat's law of partial volumes, at a constant total pressure, the volume ratio is equal to the pressure ratio. Since the reaction does not consume blending gases such as nitrogen, when the total pressure remains unchanged, for every amount of oxygen reacted, the same amount of oxygen is replenished, thereby controlling the oxygen content in the mixed gas.

[0056] The above scheme is further described below in conjunction with specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited by the scope of the following embodiments; the implementation conditions adopted in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0057] Unless otherwise specified in the following embodiments, all raw materials are obtained from commercial sources or prepared by conventional methods in the art.

[0058] In the following Examples 1-10, the above Mode 3 is adopted for operation: When the reaction starts, there is air in the gas phase chamber itself. The air in the gas phase chamber is displaced by a mixed gas pipe (a combination of oxygen and a blending gas such as nitrogen, with the volume percentage of oxygen being 8%). The displaced air can be discharged through an evacuation valve, and the evacuation valve can be closed after the displacement is completed. After multiple displacements, the supply of the mixed gas is stopped, the oxygen inlet pipe is opened, and the pressure blower is started to make the mixed gas in the gas phase chamber start to circulate in the reaction system. The oxygen is partially or completely consumed, and the remaining gas returns to the gas phase chamber and mixes with the oxygen replenished from the oxygen inlet pipe. This process is cycled. During this process, the oxygen input value of the oxygen inlet pipe and the air volume of the pressure blower are respectively controlled to control the pressure in the gas phase chamber to a preset pressure value (gauge pressure 100-3000 Pa).

[0059] In Example 11 below, the operation is carried out in the above-mentioned manner 3: When the reaction starts, there is air in the gas phase chamber itself. A mixed gas pipe (a combination of oxygen and a blending gas such as nitrogen, with the volume percentage of oxygen being 4%) is used to displace the air in the gas phase chamber (the displaced air can be discharged through the evacuation valve, and the evacuation valve can be closed after the displacement is completed). After multiple displacements, the supply of the mixed gas is stopped, and the oxygen inlet pipe is opened. The pressure blower is started to make the mixed gas in the gas phase chamber start to circulate in the reaction system. The oxygen is partially or completely consumed, and the remaining gas returns to the gas phase chamber and is mixed with the oxygen replenished from the oxygen inlet pipe. This process is cycled. During this process, the oxygen input value of the oxygen inlet pipe and the air volume of the pressure blower are respectively controlled to control the pressure in the gas phase chamber to the preset pressure value (gauge pressure 100 - 3000 Pa).

[0060] In Example 12 below, the operation is carried out in the above-mentioned manner 3: When the reaction starts, there is air in the gas phase chamber itself. A mixed gas pipe (a combination of oxygen and a blending gas such as nitrogen, with the volume percentage of oxygen being 12%) is used to displace the air in the gas phase chamber (the displaced air can be discharged through the evacuation valve, and the evacuation valve can be closed after the displacement is completed). After multiple displacements, the supply of the mixed gas is stopped, and the oxygen inlet pipe is opened. The pressure blower is started to make the mixed gas in the gas phase chamber start to circulate in the reaction system. The oxygen is partially or completely consumed, and the remaining gas returns to the gas phase chamber and is mixed with the oxygen replenished from the oxygen inlet pipe. This process is cycled. During this process, the oxygen input value of the oxygen inlet pipe and the air volume of the pressure blower are respectively controlled to control the pressure in the gas phase chamber to the preset pressure value (gauge pressure 100 - 3000 Pa).

[0061] Example 1

[0062] This example provides a preparation method of 4-oxoisophorone, and this preparation method adopts the above-mentioned Figure 1 shown reaction vessel and operation process, wherein:

[0063] Catalytic system configuration: Cupric acetate: 0.012 kg, deionized water: 1.0 kg, acetic acid: 0.45 kg are put into a 5L three-necked flask equipped with a thermometer and a stirring paddle. Stir to dissolve, and after complete dissolution, set aside.

[0064] Reaction vessel: 500L, add β-isophorone: 85.0 kg (content: 98.9 wt%), pyridine: 100 kg. Pass hot water into the jacket of the reaction vessel to control the internal temperature at 45°C, and the rotation speed of the shearing mechanism: 1450 r / min; control the pressure in the gas phase chamber to be 2000 Pa (gauge pressure), and the oxidation reaction lasts for 30 h;

[0065] After the oxidation reaction is completed, transfer the oxidation reaction solution to a recovery kettle and recover pyridine under reduced pressure. After the pyridine recovery is completed, transfer the concentrated solution in the recovery kettle to a wiped film evaporator for heavy component removal.

[0066] After heavy component removal, 90.7 kg of 4-oxoisophorone is obtained (content of 4-oxoisophorone: 97.1 wt%), and the yield is 95.1%. Its gas chromatogram is as Figure 2 shown.

[0067] Example 2

[0068] The process and process parameters of Example 2 are basically the same as those of Example 1, except that 42.5 kg of pyridine is added to a 500 L reaction vessel.

[0069] After heavy component removal, 90.1 kg of 4-oxoisophorone is obtained (content of 4-oxoisophorone: 96.9 wt%), and the yield is 94.3%.

[0070] Example 3

[0071] The process and process parameters of Example 3 are basically the same as those of Example 1, except that 212.5 kg of pyridine is added to a 500 L reaction vessel.

[0072] After heavy component removal, 91.8 kg of 4-oxoisophorone is obtained (content of 4-oxoisophorone: 97.5 wt%), and the yield is 96.7%.

[0073] Example 4

[0074] The process and process parameters of Example 4 are basically the same as those of Example 1, except that during the preparation of the catalyst system, 0.007 kg of copper acetate, 0.58 kg of deionized water, and 0.26 kg of acetic acid are added to a 5 L three-necked flask equipped with a thermometer and a stirring paddle, and stirring is started for dissolution.

[0075] After heavy component removal, 92.2 kg of 4-oxoisophorone is obtained (content of 4-oxoisophorone: 97.6 wt%), and the yield is 97.2%.

[0076] Example 5

[0077] The process and process parameters of Example 5 are basically the same as those of Example 1, except that during the preparation of the catalyst system, 0.035 kg of copper acetate, 2.9 kg of deionized water, and 1.30 kg of acetic acid are added to a 5 L three-necked flask equipped with a thermometer and a stirring paddle, and stirring is started for dissolution.

[0078] After heavy component removal, 89.4 kg of 4-oxoisophorone is obtained (content of 4-oxoisophorone: 97.1 wt%), and the yield is 93.8%.

[0079] Example 6

[0080] The process and process parameters of Example 6 are basically the same as those of Example 1, except that cooling water is introduced into the jacket of the reaction vessel to control the internal temperature of the oxidation kettle at 30 °C.

[0081] After deweighting, 92.3 kg of 4-oxoisophorone was obtained (content of 4-oxoisophorone: 97.6 wt%), and the yield was 97.3%.

[0082] Example 7

[0083] The process and process parameters of Example 7 are basically the same as those of Example 1, except that hot water is introduced into the jacket of the reaction vessel to control the internal temperature of the oxidation kettle at 50 °C.

[0084] After deweighting, 90.3 kg of 4-oxoisophorone was obtained (content of 4-oxoisophorone: 96.7 wt%), and the yield was 94.3%.

[0085] Example 8

[0086] The process and process parameters of Example 8 are basically the same as those of Example 1, except that during the preparation of the catalyst system, 0.012 kg of copper acetate, 1.0 kg of deionized water, and 0.45 kg of nitric acid aqueous solution with a content of 67.5 wt% were added to a 5 L three-necked flask equipped with a thermometer and a stirrer paddle, and stirring was started to dissolve.

[0087] After deweighting, 89.3 kg of 4-oxoisophorone was obtained (content of 4-oxoisophorone: 96.8 wt%), and the yield was 93.4%.

[0088] Example 9

[0089] The process and process parameters of Example 9 are basically the same as those of Example 1, except that during the preparation of the catalyst system, 0.012 kg of copper acetate, 1.0 kg of deionized water, and 0.45 kg of hydrochloric acid (aqueous solution of hydrogen chloride) with a content of 35.6 wt% were added to a 5 L three-necked flask equipped with a thermometer and a stirrer paddle, and stirring was started to dissolve.

[0090] After deweighting, 89.2 kg of 4-oxoisophorone was obtained (content of 4-oxoisophorone: 96.9 wt%), and the yield was 93.4%.

[0091] Example 10

[0092] The process and process parameters of Example 10 are basically the same as those of Example 1. The difference is that during the preparation of the catalytic system, 0.012 kg of copper sulfate, 1.0 kg of deionized water, and 0.45 kg of acetic acid are added into a 5 L three-necked flask equipped with a thermometer and a stirring paddle, and stirring is started for dissolution.

[0093] After deweighting, 89.0 kg of 4-oxoisophorone is obtained (the content of 4-oxoisophorone is 97.3 wt%), and the yield is 93.5%.

[0094] Example 11

[0095] The process and process parameters of Example 11 are basically the same as those of Example 1. The difference is that the operation is carried out in the above-mentioned manner 3: when the reaction starts, there is air in the gas phase chamber itself. The air in the gas phase chamber is replaced by a mixed gas pipe (a combination of oxygen and a blending gas such as nitrogen, and the volume percentage of oxygen is 4%). The replaced air can be discharged through the evacuation valve, and the evacuation valve can be closed after the replacement is completed. After multiple replacements, the supply of the mixed gas is stopped, and the oxygen inlet pipe is opened. The pressure blower is started to make the mixed gas in the gas phase chamber start to circulate in the reaction system. The oxygen is partially or completely consumed, and the remaining gas returns to the gas phase chamber and is mixed with the oxygen supplemented from the oxygen inlet pipe. This process is cycled. During this process, the oxygen input value of the oxygen inlet pipe and the air volume of the pressure blower are respectively controlled to control the pressure in the gas phase chamber to be the preset pressure value (gauge pressure 1500 Pa).

[0096] After deweighting, 90.8 kg of 4-oxoisophorone is obtained (the content of 4-oxoisophorone is 97.1 wt%), and the yield is 95.2%.

[0097] Example 12

[0098] The process and process parameters of Example 12 are basically the same as those of Example 1. The difference is that the operation is carried out in the above-mentioned manner 3: when the reaction starts, there is air in the gas phase chamber itself. The air in the gas phase chamber is replaced by a mixed gas pipe (a combination of oxygen and a blending gas such as nitrogen, and the volume percentage of oxygen is 12%). The replaced air can be discharged through the evacuation valve, and the evacuation valve can be closed after the replacement is completed. After multiple replacements, the supply of the mixed gas is stopped, and the oxygen inlet pipe is opened. The pressure blower is started to make the mixed gas in the gas phase chamber start to circulate in the reaction system. The oxygen is partially or completely consumed, and the remaining gas returns to the gas phase chamber and is mixed with the oxygen supplemented from the oxygen inlet pipe. This process is cycled. During this process, the oxygen input value of the oxygen inlet pipe and the air volume of the pressure blower are respectively controlled to control the pressure in the gas phase chamber to be the preset pressure value (gauge pressure 1500 Pa).

[0099] After removing the heavy components, 4-oxoisophorone was obtained: 89.8 kg (content of 4-oxoisophorone: 97.0 wt%), and the yield was 94.1%.

[0100] Comparative Example 1

[0101] The process and process parameters of Comparative Example 1 were basically the same as those of Example 1, except that air was continuously introduced from the bottom of the reaction phase chamber, and the remaining unreacted air was discharged outwards through the exhaust valve of the gas phase chamber.

[0102] After removing the heavy components, 4-oxoisophorone was obtained: 83.9 kg (content of 4-oxoisophorone: 96.6 wt%), and the yield was 87.5%.

[0103] Comparative Example 2

[0104] The process and process parameters of Comparative Example 2 were basically the same as those of Example 1, except that during the preparation of the catalytic system, 0.012 kg of copper acetate and 1.0 kg of deionized water were added to a 5 L three-necked flask equipped with a thermometer and a stirrer paddle, and stirring was started to dissolve.

[0105] After removing the heavy components, 4-oxoisophorone was obtained: 85.3 kg (content of 4-oxoisophorone: 96.8 wt%), and the yield was 89.2%.

[0106] The above examples are only for illustrating the technical concept and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

[0107] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values and individual point values of each range, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

Claims

1. A preparation method of 4-oxoisophorone, which prepares 4-oxoisophorone by oxidizing β-isophorone, and is characterized in that: A reaction phase chamber for accommodating the reaction system, a gas phase chamber for caching the mixed gas and communicating with the reaction phase chamber, and a connection channel for connecting the lower part of the reaction phase chamber and the gas phase chamber are respectively provided; The reaction system includes an organic base, a catalytic system and β-isophorone, and the catalytic system is composed of a copper salt, an organic acid and / or an inorganic acid and water; the copper salt is a combination of one or more selected from copper acetate, copper nitrate, copper sulfate, and copper chloride, and the organic acid and / or inorganic acid is a combination of one or more selected from acetic acid, sulfuric acid, hydrochloric acid, and nitric acid; The mixed gas contains oxygen; in terms of volume percentage, the content of oxygen in the mixed gas is 2%-15%; During the oxidation of β-isophorone, the mixed gas enters the reaction system from the lower part of the reaction phase chamber through the connection channel, and part or all of the oxygen participates in the reaction, and the unreacted gas returns to the gas phase chamber, and the pressure in the gas phase chamber is controlled to be at a preset pressure value by supplementing new oxygen to the gas phase chamber.

2. The preparation method of 4-oxoisophorone according to claim 1, characterized in that: The catalytic system is formed by dispersing a copper salt, an organic acid and / or an inorganic acid in water.

3. The preparation method of 4-oxoisophorone according to claim 1, characterized in that: The catalytic system is composed of copper acetate, acetic acid and water; or, the catalytic system is composed of copper acetate, nitric acid and water; or, the catalytic system is composed of copper acetate, hydrochloric acid and water; or, the catalytic system is composed of copper sulfate, acetic acid and water.

4. The preparation method of 4-oxoisophorone according to any one of claims 1-3, characterized in that: In terms of mass percentage, in the catalytic system, the content of the copper salt is 0.1%-2.0%, and the content of the organic acid and / or inorganic acid is 10%-50%.

5. The preparation method of 4-oxoisophorone according to claim 4, characterized in that: In terms of mass percentage, in the catalytic system, the content of the copper salt is 0.4%-1.2%, and the content of the organic acid and / or inorganic acid is 12%-35%.

6. The method for preparing 4-oxoisophorone according to any one of claims 1 to 3, characterized in that: The feeding mass ratio of the catalytic system to the β-isophorone is 0.01-0.05∶1.

7. The preparation method of 4-oxoisophorone according to claim 1, characterized in that: Both ends of the connection channel are respectively communicated with the bottom of the lower part of the reaction phase chamber and the upper part of the gas phase chamber; And / or, an oxygen inlet is provided at the upper part of the gas phase chamber, and the oxygen inlet and the connection part of the gas phase chamber communicating with the connection channel are respectively located on opposite sides of the gas phase chamber; And / or, the oxidation of β-isophorone is realized by means of a reaction vessel formed with a cavity, and the reaction phase chamber and the gas phase chamber are integrally formed to constitute the cavity.

8. The preparation method of 4-oxoisophorone according to claim 1, characterized in that: A shearing mechanism is provided at least partially at the bottom inside the reaction phase chamber, the center line of the shearing mechanism coincides with the center line of the reaction phase chamber, and the air inlet for introducing the mixed gas on the reaction phase chamber is directly opposite to the shearing mechanism; and / or, a controller for controlling the flow rate of the mixed gas is provided on the connection channel, and the controller includes a pressure blower.

9. The preparation method of 4-oxoisophorone according to claim 1, characterized in that: The preset pressure value is a gauge pressure of 100-3000 Pa; and / or, during the oxidation of β-isophorone, the reaction temperature is controlled to be 30-50 °C.

10. The preparation method of 4-oxoisophorone according to claim 1, characterized in that: The organic base is one or a combination of more than one selected from pyridine, 2-methylpyridine, 3-methylpyridine, and 4-methylpyridine; and / or, the mass ratio of the organic base to the β-isophorone in the feed is 0.5-2.5∶1.

Images