CN117304138A - A method for preparing epoxy compounds in a micro-flux continuous flow reactor - Google Patents

Abstract

The invention belongs to the technical field of chemical synthesis, and particularly relates to a method for preparing epoxide by micro-flux continuous flow. The method comprises the following steps: (1) preparation of peroxide: in a first continuous flow microstructure reactor, a solution A containing a peroxide stabilizer, hydrogen peroxide and water is contacted with an organic acid and/or anhydride and subjected to an oxidation reaction; (2) extraction: contacting the material obtained in step (1) with a first organic solvent in a second continuous flow microstructure reactor and extracting; (3) liquid phase separation: carrying out liquid-liquid separation on the material obtained in the step (2) to obtain acid water and an organic phase containing peroxyacid; (4) epoxidation reaction: in a third continuous flow microstructured reactor, the organic phase is contacted with solution B comprising the substrate and the second organic solvent and epoxidation reaction takes place. The method provided by the invention has the advantages of high conversion rate, safety, high efficiency and environmental protection.

Description

A method for preparing epoxy compounds using a microflux continuous flow reactor

Technical Field

The invention belongs to the technical field of chemical synthesis, and in particular relates to a method for preparing epoxide by micro-flux continuous flow.

Background Art

Alicyclic epoxy resins and their cured products have no residual chlorine and aromatic groups, and have excellent comprehensive properties such as processability, thermal stability, electrical insulation and resistance to ultraviolet radiation. They have been widely used in important industrial fields such as aerospace, microelectronics packaging and motor insulation. In response to the increasingly high performance and functional requirements of modern industry for polymer materials, the synthesis and performance research of alicyclic epoxy resins has been very active in recent years.

Cycloaliphatic epoxy resins have a certain molecular weight and molecular structure, and the synthesis methods are diverse. They have strong structural designability and are easy to change their chemical structure according to actual needs, thereby adjusting the physical properties of the resin. The outstanding characteristics of the physical properties of cycloaliphatic epoxy resins are that they are generally liquid at room temperature before curing and have low viscosity. They can often be directly used in construction operations such as coatings and electronic packaging materials without solvent dilution, which is convenient for process operations such as potting, pouring or vacuum injection. The rigid structure of the alicyclic ring and the high cross-linking density of the cured product give it good bonding strength to different substrates, high heat deformation temperature, excellent chemical resistance, and mechanical and electrical properties. Cycloaliphatic epoxy resins usually do not contain strong ultraviolet chromophores such as aromatic rings. When exposed to high-voltage arcs, they decompose to produce small molecular volatiles such as carbon dioxide, carbon monoxide, and water, and will not generate free carbon to form a conductive path, so that it has excellent high-voltage leakage resistance. Due to its excellent comprehensive properties, alicyclic epoxy resins have been used in recent years in the fields of ultra-large-scale integrated circuit packaging, printed circuit board manufacturing, special photocuring coatings, large-capacity and high-temperature resistant motor insulation materials for vacuum pressure impregnation technology, etc.

The first prior art method is to prepare alicyclic epoxy resin using a traditional catalyst method. Such catalysts usually contain heavy metal ions (such as tungsten, molybdenum, etc.), so the reaction product also contains a certain amount of heavy metal ion residues; due to the influence of heavy metal ion-containing catalysts, the final product also has heavy metal ion residues. This trace amount of heavy metal ions also affects the curing speed (i.e., gel time) of the product, so that the cross-linking within the molecule during curing is affected, resulting in a prolonged gel time of the product, thereby affecting production efficiency and product quality; and such catalysts are usually expensive and cannot be reused, which is not conducive to large-scale industrial production. The second method is to use the Union Carbide Corporation peracid oxidation method. This method uses a high concentration of peracid, and the reaction is highly exothermic after initiation, and the residual peroxide group is easy to aggregate, which will cause a violent explosion after triggering, and there is a great safety hazard.

The existing technology has the defects that epoxy compounds cannot be produced continuously, have low conversion rate, poor safety, are easy to carry heavy metal impurities, and are not suitable for large-scale production.

Summary of the invention

The purpose of the present invention is to overcome the above problems existing in the prior art and provide a method for preparing epoxides by microflux continuous flow. The method provided by the present invention has high conversion rate, is safe, efficient and environmentally friendly.

The inventors of the present invention have found that the new synthesis technology of microflux reaction (microtube, microchannel) is particularly suitable for the production of epoxides with heterogeneous reactions. The inventors of the present invention have further found that the presence of water in the production process of epoxides can lead to the occurrence of side reactions and hydrolysis of the products; therefore, the inventors of the present invention have rearranged the reaction method, effectively improving the conversion rate, selectivity, product quality and yield of the reaction.

The present invention provides a method for preparing an epoxy compound, comprising the following steps:

(1) Preparing peroxide: In a first continuous flow microstructured reactor, a solution A containing a peroxide stabilizer, hydrogen peroxide and water is contacted with an organic acid and/or anhydride to undergo an oxidation reaction;

(2) Extraction: In a second continuous flow microstructured reactor, the material obtained in step (1) is contacted with a first organic solvent and extraction is performed;

(3) liquid phase separation: subjecting the material obtained in step (2) to liquid-liquid separation to obtain acid water and an organic phase containing peroxyacid;

(4) Epoxidation reaction: In the third continuous flow microstructured reactor, the organic phase is contacted with a solution B containing a substrate and a second organic solvent and an epoxidation reaction occurs.

Through the above technical solution, the present invention has at least the following advantages compared with the prior art:

(1) The present invention has a small effective liquid holding capacity and is continuous, which can achieve full mixing and efficient heat transfer in a short time, greatly shortening the reaction time (from 8-24h to less than 300s);

(2) The present invention separates the oxidation reaction and the epoxidation reaction, so that the exothermic reaction process is carried out step by step, which is easier to control and safer;

(3) The epoxidation reaction of the present invention does not contain water, which greatly reduces the occurrence of side reactions and hydrolysis of products, effectively improves the conversion rate, selectivity, product quality and yield of the reaction, and is of great significance. Therefore, the present invention is a safe, efficient and environmentally friendly continuous flow production process;

(4) The multi-link materials of the present invention can be recycled or reused, which increases resource utilization and achieves the purpose of green environmental protection;

(5) The continuous flow process of the present invention eliminates the phenomenon of temperature runaway during the reaction process, thereby achieving safety and stability of the entire process; and through reasonable distribution of flow, it can achieve full-automatic or semi-automatic continuous operation, greatly improving production efficiency.

The endpoints and any values of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of an epoxidation reaction system to which the method of the present invention can be applied;

FIG2 is a schematic diagram of an epoxidation reaction unit in the system shown in FIG1 ;

FIG3 is a schematic diagram of a quenching unit and a cleaning unit in the system shown in FIG1 ;

FIG. 4 is a schematic diagram of a purification unit in the system shown in FIG. 1 .

Description of Reference Numerals

P-1, first delivery pump; P-2, second delivery pump; P-3, third delivery pump; P-4, fourth delivery pump; R-1, first continuous flow microstructure reactor; R-2, second continuous flow microstructure reactor; R-3, third continuous flow microstructure reactor; S-1, liquid-liquid separator; T-1, alkali washing tower; T-2, water washing tower; E-1, first condenser; E-2, second condenser; E-3, third condenser; D-1, primary thin film evaporator; D-2, secondary thin film evaporator; C-1, finished product tank; C-2, solvent tank.

DETAILED DESCRIPTION

The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

The present invention provides a method for preparing an epoxy compound, comprising the following steps:

(1) Preparing peroxide: In a first continuous flow microstructured reactor, a solution A containing a peroxide stabilizer, hydrogen peroxide and water is contacted with an organic acid and/or anhydride to undergo an oxidation reaction;

(2) Extraction: In a second continuous flow microstructured reactor, the material obtained in step (1) is contacted with a first organic solvent and extraction is performed;

(3) liquid phase separation: subjecting the material obtained in step (2) to liquid-liquid separation to obtain acid water and an organic phase containing peroxyacid;

(4) Epoxidation reaction: In the third continuous flow microstructured reactor, the organic phase is contacted with a solution B containing a substrate and a second organic solvent and an epoxidation reaction occurs.

The present invention performs continuous micro-reactions in multiple steps, significantly improving the reaction speed and greatly reducing the generation of by-products. A material containing the target product (epoxide) can be obtained through the above epoxidation reaction.

The main purpose of step (1) is to cause an oxidation reaction to obtain peroxide.

The step (1) is carried out in a first continuous flow microstructured reactor, and two streams of materials enter the first continuous flow microstructured reactor in parallel, one stream is the solution A, which is a solution containing a peroxide stabilizer, hydrogen peroxide and water, and the other stream is the organic acid and/or anhydride.

The reaction conditions in the first continuous flow microstructure reactor can be set according to the needs of the reaction. For example, the conditions of the first continuous flow microstructure reactor may include: a temperature of 30-60°C, preferably 40-50°C; a time of 30-600s, preferably 30-100s.

The main purpose of step (2) is to extract the intermediate product obtained by oxidation in step (1) into the organic phase (the first organic solvent).

The step (2) is carried out in a second continuous flow microstructured reactor, and two streams of materials enter the second continuous flow microstructured reactor in parallel, one stream is the material obtained in step (1), and the other stream is the first organic solvent.

Extraction occurs in the second continuous flow microstructure reactor, so there are no special requirements for the conditions. For example, the conditions of the second continuous flow microstructure reactor may include: temperature of 15-25°C, preferably 20-23°C; time of 30-600s, preferably 30-100s.

The main purpose of step (3) is to perform liquid-liquid separation on the material obtained in step (2) to obtain acid water and an organic phase containing peroxyacid, so as to form an anhydrous environment for the epoxidation reaction. The inventors of the present invention have found that the presence of water in the epoxide production process can lead to the occurrence of side reactions and hydrolysis of the product, and thus the reaction method has been readjusted and arranged, thereby effectively improving the quality and yield of the product.

The liquid-liquid separation in step (3) can be carried out in a conventional manner in the art, and the acid water and the organic phase containing the peroxyacid can be separated, for example, by standing.

The main purpose of step (4) is to cause the intermediate product in the organic phase to undergo epoxidation reaction to obtain a material containing the target product epoxide.

The step (4) is carried out in a third continuous flow microstructured reactor, and two streams of materials enter the third continuous flow microstructured reactor in parallel, one stream is the organic phase (containing the intermediate product) separated in step (3), and the other stream is solution B, which is a solution containing a substrate and a second organic solvent.

The reaction conditions in the third continuous flow microstructure reactor can be set according to the needs of the reaction. For example, the conditions of the third continuous flow microstructure reactor may include: a temperature of 40-90°C, preferably 70-90°C; a time of 30-600s, preferably 30-100s.

After step (4), the obtained material is the material containing the final target product.

The first continuous flow microstructured reactor, the second continuous flow microstructured reactor and the third continuous flow microstructured reactor may be the same or different, and may be independently selected from microchannel reactors, microtube reactors, tubular reactors and the like. The microstructured reactors may be selected from commercial brands or customized. The reactor material is not limited to non-metallic materials such as quartz, glass, silicon carbide, and metal materials such as stainless steel.

In steps (1)-(4), a series of chemical reactions occur to obtain epoxides. The specific reaction routes and the raw materials used in these chemical reactions can be the same as those conventionally used in the art to prepare epoxides. The following is an exemplary description of the reaction materials more suitable for the method of the present invention.

The solution A in step (1) is a solution containing a peroxide stabilizer, hydrogen peroxide and water. The solution A can be obtained, for example, by dissolving a peroxide stabilizer in an aqueous hydrogen peroxide solution (commonly known as "hydrogen peroxide").

The peroxide stabilizer is, for example, selected from one or more of sodium phosphate, sodium dipolyphosphate, sodium tripolyphosphate and sodium polyphosphate.

Preferably, the concentration of the peroxide stabilizer in the solution A is 0.1-1 wt %, more preferably 0.1-0.5 wt %.

The hydrogen peroxide is usually present in the form of an aqueous solution (commonly known as hydrogen peroxide). The concentration of the hydrogen peroxide used to prepare solution A is, for example, 30-70% by weight, preferably 35-55% by weight.

The term "organic acid and/or anhydride" as a whole means that the material includes an organic acid, or an anhydride, or a mixture of an organic acid and anhydride.

Preferably, the organic acid and/or anhydride is selected from one or more of acetic acid, propionic acid, butyric acid, acetic anhydride, propionic anhydride and succinic anhydride.

The amount of each material used in step (1) is related to the amount of substrate added in step (4).

Preferably, the equivalent ratio of the substrate to the hydrogen peroxide is 1:(1.5-4), more preferably 1:(1.8-3).

Preferably, the equivalent ratio of the substrate to the organic acid or anhydride is 1:(1-5), more preferably 1:(1-3).

In the present invention, the term "equivalent ratio" means the molar ratio of each substance.

For example, the substrate is a cyclohexene organic substance, including but not limited to one or more of the following substances:

For example, the target product, i.e., epoxide, includes, but is not limited to, one or more of the following substances:

The first organic solvent used in step (2) and the second organic solvent used in step (4) may be the same or different, and may be independently selected from one or more of aromatic hydrocarbon solvents, halogenated hydrocarbon solvents and ester solvents.

The aromatic hydrocarbon solvent is, for example, one or more selected from benzene, toluene, ethylbenzene and xylene.

The halogenated hydrocarbon solvent is, for example, one or more selected from the group consisting of dichloromethane, monochloroethane, dichloroethane and chloroform.

The ester solvent is, for example, one or more selected from ethyl acetate, propyl acetate, butyl acetate, dimethyl carbonate and diethyl carbonate.

Preferably, the first organic solvent and the second organic solvent are each independently selected from one or more of dichloromethane, dichloroethane and ethyl acetate.

The mass ratio of the substrate to the second organic solvent is, for example, 1:(1-4), preferably 1:(1.5-3).

The material containing the target product can be subsequently processed in a conventional manner in the art to obtain the final product.

According to a specific embodiment, the method further comprises the following steps which are performed after step (4): (5) quenching; contacting the material obtained in step (4) with a base to quench the reaction; and optionally (6) washing; and/or, (7) purification.

The main purpose of step (5) is to quench the reaction by contacting the material obtained in step (4) with a base.

The main purpose of step (6) is to clean the material obtained in step (5).

According to a specific embodiment, the material obtained in step (4) is continuously or semi-continuously passed through a continuous alkali washing tower (wherein it is contacted with an alkaline aqueous solution) and a continuous water washing tower (for washing).

The main purpose of step (7) is to extract and purify the washed liquid to obtain the product.

According to a specific embodiment, the purification is performed by thin film evaporation.

Impurities such as residual solvents can be effectively removed by the thin film evaporation process.

According to a preferred embodiment, the purification comprises: continuously or semi-continuously subjecting the material obtained in step (6) to thin film evaporation (for example, in a continuous thin film evaporator).

Preferably, the conditions for the primary thin film evaporation include: a temperature of 60-120° C., more preferably 80-100° C.; a vacuum degree of 50-1000 Pa, more preferably 300-500 Pa.

Preferably, the conditions for the secondary thin film evaporation include: a temperature of 100-130° C., more preferably 120-150° C.; a vacuum degree of 5-100 Pa, more preferably 20-50 Pa.

Through two distillations, the solvent can be completely removed. After distillation, the residual impurities in the product are also effectively removed, which greatly improves the product quality and increases the stability of the product.

In order to achieve maximum resource utilization and green production, preferably, the method also includes recovery or recycling processing.

The recovery or recycling process may include at least one of the following operations:

Operation 1: reacting the alkaline aqueous solution separated after quenching obtained in step (5) with the acidic aqueous solution separated after extraction obtained in step (2) to obtain an organic acid salt by-product;

Operation 2: using the alkaline aqueous solution separated after washing obtained in step (6) in step (5);

Operation 3: using the organic solvent separated after purification obtained in step (7) in the operation requiring the use of an organic solvent in the method;

Operation 4: using the aqueous solution separated after concentration, quenching or washing in the method in the operation requiring the use of water in the method.

The first operation is a recovery operation, which can obtain by-products to realize additional economic value. The specific method includes: reacting at least part of the alkaline aqueous solution separated after quenching obtained in step (5) with the acidic aqueous solution separated after extraction obtained in step (2) to generate a pre-recovered target organic acid salt, and further processing (such as concentration, crystallization, filtration, etc.) to finally obtain an organic acid salt by-product.

The second operation is a circulation operation, which can circulate the alkali in the system. The specific method includes: using at least part of the alkaline aqueous solution separated after washing obtained in step (6) for reaction quenching in step (5); and/or using it as a water source in other steps.

The operation three is a circulation operation, which can recycle the organic solvent in the system. The specific method includes: using the organic solvent separated after purification obtained in step (7) in the operation requiring the use of organic solvent in the method, such as for extraction and/or for preparing solution B.

The fourth operation is a circulation operation, which can circulate water in the system. The specific method includes: using the aqueous solution separated after concentration, quenching or washing in the method in the operation that requires the use of water in the method.

Therefore, the present invention can maximize resources. The alkaline water separated by quenching is neutralized with the acid water separated by extraction, and after concentration, crystallization and filtration, a salt containing crystal water can be obtained, which can be sold as a by-product after packaging. The water separated by washing can be used as a water source for the quenching process, and the water concentrated by neutralization can be used as a water source for the washing process; the solvent recovered in the purification process can be recycled.

Each step and operation of the method of the present invention can be carried out continuously or semi-continuously.

The method may further include a control operation, which may be performed through a control module, and may detect and regulate each link of each device, and may calculate a reasonable flow rate in each component so that the reaction proceeds continuously and smoothly.

In order to facilitate understanding of the implementation of the method of the present invention, an epoxidation reaction system to which the method of the present invention can be applied is exemplified below, as shown in Figure 1. The system shown in Figure 1 can be divided into multiple units, wherein the epoxidation reaction unit is shown in Figure 2, the quenching unit and the cleaning unit are shown in Figure 3, and the purification unit is shown in Figure 4. The system is exemplarily described below in conjunction with the accompanying drawings.

In one example, the epoxidation unit is as shown in FIG. 1 and FIG. 2 .

According to a specific embodiment, the system comprises a first continuous flow microstructured reactor R-1, a second continuous flow microstructured reactor R-2, a liquid-liquid separator S-1 and a third continuous flow microstructured reactor R-3 which are connected in sequence in the direction of logistics (these devices constitute the epoxidation unit); wherein,

One material inlet of the first continuous flow microstructure reactor R-1 is connected to a solution A source, which is used to provide a solution A containing a peroxide stabilizer, hydrogen peroxide and water; another material inlet is connected to an acid source, which is used to provide an organic acid and/or anhydride; one material inlet of the second continuous flow microstructure reactor R-2 is connected to a material outlet of the first continuous flow microstructure reactor R-1; another material inlet is connected to a first organic solvent source; a material inlet of the liquid-liquid separator S-1 is connected to a material outlet of the second continuous flow microstructure reactor R-2; one material inlet of the third continuous flow microstructure reactor R-3 is connected to an organic phase outlet of the liquid-liquid separator S-1; another material inlet is connected to a solution B source, which is used to provide a solution B containing a substrate and a second organic solvent.

The system may also be provided with a plurality of delivery pumps as required, for example, a first delivery pump P-1 for delivering solution A, a second delivery pump P-2 for delivering organic acid and/or anhydride, a third delivery pump P-3 for delivering the first organic solvent, and a fourth delivery pump P-4 for delivering solution B.

According to a specific embodiment, the system further includes a concentration and crystallization unit. The water phase outlet of the liquid-liquid separator S-1 is connected to the concentration and crystallization unit, and the concentration and crystallization unit includes a neutralization device, a concentration device, a crystallization device and a filtering device connected in sequence, wherein the material inlet of the neutralization device is connected to the water phase outlet of the liquid-liquid separator S-1 to input an acidic aqueous solution, and the material inlet of the neutralization device is also connected to the water phase outlet of the alkali washing tower T-1 (as shown in Figures 1 and 3) to input an alkaline aqueous solution, so that the acidic aqueous solution and the alkaline aqueous solution undergo a neutralization reaction in the neutralization device to generate a salt, which is sequentially concentrated in the concentration device, crystallized in the crystallization device, and filtered in the filtering device, and can also be dried in a drying device to finally obtain an organic acid salt by-product.

The liquid-liquid separator S-1 may also include a gas phase outlet connected to the outside world or a subsequent treatment process.

The first continuous flow microstructure reactor R-1 is the main place where step (1) occurs; the second continuous flow microstructure reactor R-2 is the main place where step (2) occurs; the liquid-liquid separator S-1 is the main place where step (3) occurs; the third continuous flow microstructure reactor R-3 is the main place where step (4) occurs; and the concentration and crystallization unit is the main place where operation one occurs.

In one example, the quenching unit and the cleaning unit are as shown in FIG. 3 and FIG. 1 .

The quenching unit is used to quench the reaction of the material from the third continuous flow microstructure reactor R-3. The quenching unit mainly includes an alkali washing tower T-1. The alkali washing tower T-1 can use a conventional commercial alkali washing tower in the art.

In one example, the material outlet of the third continuous flow microstructure reactor R-3 is connected to the material inlet of the alkali washing tower T-1; another material inlet of the alkali washing tower T-1 is connected to an alkali source, and the alkali source is used to provide an alkaline aqueous solution; so that in the alkali washing tower T-1, under the action of the alkali, the material from the third continuous flow microstructure reactor R-3 is quenched by reaction. The alkali washing tower T-1 is the main place where step (5) occurs. The material in the alkali washing tower T-1 is divided into an organic phase and an aqueous phase, wherein the organic phase enters the cleaning unit.

According to a preferred embodiment, the water phase separated from the alkali washing tower T-1 enters the concentration crystallization unit to perform the operation one.

The cleaning unit is used to wash the reaction products in the material at the outlet of the organic material of the alkali washing tower. The cleaning unit mainly includes a water washing tower T-2. The water washing tower T-2 can use a conventional commercially available water washing tower in the art. The water washing tower T-2 is the main place where the step (6) occurs. The material of the water washing tower T-2 is divided into an organic phase and an aqueous phase, wherein the organic phase enters the purification unit.

According to a preferred embodiment, the water phase separated by the water washing tower T-2 is recovered and carried out in the operation two and/or operation four, that is, the water phase outlet of the water washing tower T-2 is connected to the alkaline aqueous solution inlet of the alkali washing tower T-1 and/or the water phase inlet of other equipment requiring water.

In one example, the purification unit is as shown in FIG. 1 and FIG. 4 .

The purification unit is used to purify the reaction product to obtain the final epoxide product. The purification unit is the main place where step (7) occurs. The purification unit includes a primary thin film evaporator D-1 and a secondary thin film evaporator D-2 connected in sequence, which are used to purify the material from the cleaning unit, and the purified material enters the finished product tank C-1 for collection; the purification unit also includes condensers respectively connected to the gas phase outlets of the primary thin film evaporator D-1 and the secondary thin film evaporator D-2 (for example, the first condenser E-1 and the second condenser E-2 connected to the primary thin film evaporator D-1, and the third condenser E-3 connected to the secondary thin film evaporator D-2) for condensing the solvent and collecting it, and the collected solvent enters the solvent tank C-2 for storage.

According to a preferred embodiment, the solvent collected in the solvent tank C-2 is connected to other equipment that needs to use an organic solvent to achieve the operation three.

The purification unit may also include other conventional equipment in the art, such as a crude product receiving tank, a transfer pump and a heavy component receiving tank, so that: the clarified reaction liquid after continuous separation is pumped into the primary thin film evaporation device area, the solvent enters the solvent receiving tank through the first condenser and the second condenser, the crude product enters the crude product receiving tank and is pumped into the secondary thin film evaporation device area through the first transfer pump, the light component enters the solvent tank C-2 through the third condenser, and the heavy component enters the finished product tank C-1.

According to a preferred embodiment, the system further includes a control module for controlling the operation of the system. Thus, by connecting the processes of peroxide preparation, extraction, phase separation, reaction, quenching, cleaning, purification in series, and by reasonable distribution of flow, full-automatic or semi-automatic continuous operation can be achieved, which greatly improves production efficiency; and by means of a joint control system, the continuous flow process also eliminates the phenomenon of temperature rise during the reaction process, and the safety and stability of the whole process can be achieved. It can achieve continuity, miniaturization, sealing, automation, and modularization. If modules such as online detection and data monitoring are added, the intelligentization of autonomous learning and control can be finally achieved through modeling and algorithms.

The present invention adopts the characteristics of a microflux continuous flow reactor, which has a small effective liquid holding capacity and is continuous, and can achieve full mixing and efficient heat transfer in a short time, greatly shortening the reaction time. The present invention separates the oxidation reaction and the epoxidation reaction, and promotes the exothermic reaction process to proceed step by step, which is easier to control and safer. At the same time, the extracted peracid solution is substantially free of water, which greatly reduces the occurrence of side reactions and the hydrolysis of the product, and is of great significance for improving the conversion rate, selectivity, product quality, and yield of the reaction. Therefore, the present invention is a safe, efficient, and environmentally friendly continuous flow production process.

The alkaline water generated in the quenching process of the present invention can be neutralized with the acid water in the extraction step, and the by-product obtained after concentration and crystallization can be sold as a product, thereby increasing resource utilization. The washing water can also be recycled in the quenching process, and the solvent in the purification process can be reused, thereby realizing the recycling of resources and achieving the purpose of green environmental protection.

The present invention will be described in detail below by way of examples. The embodiments described in the present invention are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

The following embodiments are all carried out in the system shown in Figures 1 to 4.

The following examples prepare different epoxides.

Example 1: 3,4-Epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexyl methyl ester

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (3.6 eq of hydrogen peroxide) to obtain a solution A; 3-cyclohexene-1-carboxylic acid-3-cyclohexene-1-methyl ester is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (2.4 eq) are respectively pumped into a first continuous flow microstructured reactor via a precise metering pump and continuously reacted at a temperature of 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor via a precise metering pump and continuously extracted at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor via a precise metering pump and continuously reacted at 85±2°C for 45 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be further recycled.

Example 2: 3,4-Epoxycyclohexylmethyl methacrylate

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (1.5 eq of hydrogen peroxide) to obtain a solution A; 3-cyclohexenylmethyl methacrylate is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (1.2 eq) are respectively pumped into a first continuous flow microstructured reactor via a precise metering pump and continuously reacted at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor via a precise metering pump and continuously extracted at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor via a precise metering pump and continuously reacted at 76±2°C for 60 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be further recycled.

Example 3: (3,4-epoxycyclohexyl)methyl acrylate

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (1.6 eq of hydrogen peroxide) to obtain a solution A; 3-cyclohexenyl methacrylate is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (1.2 eq) are respectively pumped into a first continuous flow microstructured reactor via a precise metering pump and continuously reacted at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor via a precise metering pump and continuously extracted at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor via a precise metering pump and continuously reacted at 80±2°C for 55 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be further recycled.

Example 4: Di(3,4-epoxycyclohexylmethyl)adipate

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (3.6 eq of hydrogen peroxide) to obtain a solution A; di(cyclohex-3-enylmethyl) adipate is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (2.4 eq) are respectively pumped into a first continuous flow microstructured reactor via a precise metering pump and reacted continuously at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor via a precise metering pump and extracted continuously at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor via a precise metering pump and reacted continuously at 75±2°C for 78 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be further recycled.

Experimental Example 5: 4,4'-bis(1,2-epoxycyclohexane)

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (3.6 eq of hydrogen peroxide) to obtain a solution A; dicyclohexyl-3,3'-diene is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (2.4 eq) are respectively pumped into a first continuous flow microstructured reactor via a precise metering pump and continuously reacted at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor via a precise metering pump and continuously extracted at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor via a precise metering pump and continuously reacted at 88±2°C for 50 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be recycled.

Experimental Example 6: 4-vinyl cyclohexene oxide

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (1.5 eq of hydrogen peroxide) to obtain a solution A; vinyl cyclohexene is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (1.2 eq) are respectively pumped into a first continuous flow microstructured reactor via a precise metering pump and continuously reacted at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor via a precise metering pump and continuously extracted at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor via a precise metering pump and continuously reacted at 80±2°C for 40 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be further recycled.

Experimental Example 7: 4-vinyl-1-cyclohexene diepoxide

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (3.0 eq of hydrogen peroxide) to obtain a solution A; vinyl cyclohexene is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (2.4 eq) are respectively pumped into a first continuous flow microstructured reactor via a precise metering pump and continuously reacted at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor via a precise metering pump and continuously extracted at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor via a precise metering pump and continuously reacted at 82±2°C for 63 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be recycled.

Experimental Example 8: Dicyclopentadiene diepoxide

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (3.6 eq of hydrogen peroxide) to obtain a solution A; dicyclopentadiene is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (2.4 eq) are respectively pumped into a first continuous flow microstructured reactor via a precise metering pump and continuously reacted at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor via a precise metering pump and continuously extracted at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor via a precise metering pump and continuously reacted at 78±2°C for 90 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be further recycled.

Experimental Example 9: 1,2,5,6-Diepoxytetrahydroindene

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (3.6 eq of hydrogen peroxide) to obtain a solution A; tetrahydroindene is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (2.4 eq) are respectively pumped into a first continuous flow microstructured reactor by precise metering pumps to react continuously at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor by precise metering pumps to extract continuously at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor by precise metering pumps to react continuously at 72±2°C for 72 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be recycled.

Experimental Example 10: 1,4-cyclohexanedimethanol bis(3,4-epoxycyclohexanecarboxylate)

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (3.6 eq of hydrogen peroxide) to obtain a solution A; a substrate is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (2.4 eq) are respectively pumped into a first continuous flow microstructured reactor by precise metering pumps and continuously reacted at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor by precise metering pumps and continuously extracted at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor by precise metering pumps and continuously reacted at 75±2°C for 89 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be further recycled.

Experimental Example 11: 6-(7-oxobicyclo[4.1.0]heptyl-3-methoxy)-6-oxohexyl ester

(1) Reaction: a peroxide stabilizer is dissolved in an aqueous hydrogen peroxide solution (3.6 eq of hydrogen peroxide) to obtain a solution A; a substrate is dissolved in an organic solvent (1 eq of olefin) to obtain a solution B; solution A and acetic anhydride (2.4 eq) are respectively pumped into a first continuous flow microstructured reactor by precise metering pumps to react continuously at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are respectively pumped into a second continuous flow microstructured reactor by precise metering pumps to extract continuously at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are respectively pumped into a third continuous flow microstructured reactor by precise metering pumps to react continuously at 80±2°C for 56 seconds to obtain a reaction solution.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be further recycled.

Experimental Example 12: 4,5-Epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester

(1) Reaction: The peroxide stabilizer is dissolved in a hydrogen peroxide aqueous solution (1.5 eq of hydrogen peroxide) to obtain solution A; tetrahydrophthalic acid diglycidyl ester is dissolved in an organic solvent (1 eq of olefin) to obtain solution B; solution A and acetic anhydride (1.2 eq) are pumped into the first continuous flow microstructure reactor by precise metering pumps to react continuously at 45±2°C for 60 seconds to obtain a peracid aqueous solution; the peracid aqueous solution and the solvent are pumped into the second continuous flow microstructure reactor by precise metering pumps to extract continuously at 22±2°C for 40 seconds, and the extracted solution is passed through a continuous liquid-liquid separator to obtain a peracid organic solution; the peracid organic solution and solution B are pumped into the third continuous flow microstructure reactor by precise metering pumps to react continuously at 88±2°C for 42 seconds to obtain a reaction solution. (2) Separation: The reaction solution is continuously (semi-continuously) passed through a continuous alkali washing tower and a continuous water washing tower to achieve a two-step process of quenching and washing to obtain a clarified reaction solution.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by extraction can be neutralized and concentrated to obtain a saturated salt solution. The salt containing crystal water obtained by filtration after crystallization can be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be further recycled.

Comparative Example 1-12: Synthesis of the substance corresponding to Experimental Example 1-12, except that the reaction process contains water, the steps are as follows:

(1) Reaction: dissolving a peroxide stabilizer and sodium acetate in a hydrogen peroxide aqueous solution to obtain a solution A; dissolving a substrate and acetic anhydride in an organic solvent to obtain a solution B; pumping the solution A and the solution B into a continuous flow microstructure reactor through a precise metering pump for continuous reaction to obtain a reaction solution. The specific reaction conditions are respectively carried out according to the reaction conditions in the corresponding embodiments.

(2) Separation: The reaction liquid is continuously (semi-continuously) passed through a liquid-liquid separator, a continuous alkali washing tower, and a continuous water washing tower to achieve phase separation, quenching, and washing in three steps to obtain a clarified reaction liquid.

(3) Purification: Through reasonable flow control, the clarified reaction liquid is continuously (semi-continuously) passed through a continuous thin film evaporator (first-stage thin film evaporation and second-stage thin film evaporation in sequence) to achieve the purification process operation and obtain the finished product. After the process is stabilized, it is run stably for 5 hours, and the reaction liquid is collected every hour for treatment, and the detection indicators are compared with the standard sample and (or) literature for confirmation.

(4) Resource maximization: The alkaline water separated by quenching and the acidic water separated by liquid-liquid separation are neutralized and concentrated to obtain a saturated solution of the catalyst. The catalyst containing crystal water obtained by filtration after crystallization can be used to prepare solution A, and the excess can also be sold as a by-product. The water separated by the concentration, quenching and washing process can be reused, among which the water separated by the concentration can be used in the washing process, and the water separated by the washing process can be used in the quenching process. The solvent recovered in the purification step can be recycled.

Table 1

It can be seen from Examples 1-12 and Comparative Examples 1-12 in Table 1 that the conversion rate of the epoxide synthesized by the method of the present invention is higher and the content of ring-opening impurities is significantly reduced.

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims (10)

1. A method for preparing epoxy compounds, characterized in that it includes the following steps: (1) Preparing peroxide: In the first continuous flow microstructure reactor, solution A containing peroxide stabilizer, hydrogen peroxide and water is contacted with organic acid and/or acid anhydride and an oxidation reaction occurs; (2) Extraction: In the second continuous flow microstructure reactor, the material obtained in step (1) is contacted with the first organic solvent and extraction occurs; (3) Liquid phase separation: The material obtained in step (2) is subjected to liquid-liquid separation to obtain acid water and an organic phase containing peroxyacid; (4) Epoxidation reaction: In the third continuous flow microstructure reactor, the organic phase is contacted with solution B containing the substrate and the second organic solvent and an epoxidation reaction occurs. 2. The method according to claim 1, wherein the method further includes the following steps continued after step (4): (5) Quenching; contact the material obtained in step (4) with a base to quench the reaction; and optionally (6) washing; and/or, (7) purification. 3. The method according to claim 2, wherein the method further comprises recovery or recycling processing, the recycling or recycling processing includes at least one of the following operations: Operation 1: react the alkaline aqueous solution separated after quenching obtained in step (5) with the acidic aqueous solution separated after extraction obtained in step (2) to obtain organic acid salt by-products; Operation 2: Use the alkaline aqueous solution separated after cleaning obtained in step (6) in step (5); Operation 3: Use the organic solvent separated after purification obtained in step (7) in operations that require the use of organic solvents in the method; Operation 4: Use the aqueous solution separated after concentration, quenching or washing in the method for operations that require the use of water. 4. The method according to any one of claims 1-3, wherein in step (1), the reaction temperature of the first continuous flow microstructure reactor is 30-60°C, and the reaction time is 30-60°C. 600s. 5. The method according to any one of claims 1-3, wherein in step (1), the peroxide stabilizer is selected from the group consisting of sodium phosphate, sodium dimerphosphate, sodium tripolyphosphate and polyphosphate. One or more kinds of sodium phosphate, the concentration of the peroxide stabilizer in the solution A is 0.1-1% by weight. 6. The method according to any one of claims 1-3, wherein in step (1), the organic acid and/or anhydride is selected from the group consisting of acetic acid, propionic acid, butyric acid, acetic anhydride, propionic anhydride and One or more of succinic anhydride. 7. The method according to any one of claims 1-3, wherein in step (2), the reaction temperature of the second continuous flow microstructure reactor is 15-25°C, and the reaction time is 30-600s . 8. The method according to any one of claims 1-3, wherein the first organic solvent and the second organic agent in step (4) are each independently selected from aromatic hydrocarbon solvents, halogenated hydrocarbon solvents and One or more ester solvents; Preferably, the first organic solvent and the second organic agent in step (4) are each independently selected from benzene, toluene, ethylbenzene, xylene, dichloromethane, monochloroethane, dichloroethane, chloroform, One or more of ethyl acetate, propyl acetate, butyl acetate, dimethyl carbonate and diethyl carbonate. 9. The method according to any one of claims 1-3, wherein in step (4), the reaction temperature of the third continuous flow microstructure reactor is 40-90°C, and the reaction time is 30-90°C. 600s; Preferably, the substrate is a cyclohexene organic compound, the equivalent ratio of the cyclohexene organic compound to the hydrogen peroxide in step (1) is 1:(1.5-4), and the substrate and the hydrogen peroxide are 1:(1.5-4). The equivalent ratio of organic acid or anhydride is 1:(1-5). 10. The method according to claim 2 or 3, wherein, in step (7), the purification includes sequentially subjecting the material obtained in step (6) to first-level thin film evaporation and second-level thin film evaporation; the first-level thin film evaporation The conditions for evaporation include: the temperature is 60-120°C, and the vacuum degree is 50-1000Pa; the conditions for the secondary thin film evaporation include: the temperature is 100-130°C, and the vacuum degree is 5-100Pa.