A method and device for preparing prochloraz using microfluidic field reaction technology

Abstract

The invention discloses a method and device for preparing prochloraz using microfluidic reaction technology, and the preparation method comprises the following steps: 2,4,6-trichlorophenol is dissolved with liquid caustic soda and an excess of 1,2-dichloroethane is pumped into a microfluidic reactor to react to obtain 2,4,6-trichlorophenoxyethyl chloride, and then ammoniated with n-propylamine in a microchannel reactor after liquid separation distillation and refining to obtain N-(2,4,6-trichlorophenoxyethyl) propylamine, and in the presence of triethylamine, a microfluidic dynamic reactor is used to generate acyl chloride with triphosgene and then react with imidazole to obtain the final product prochloraz. Wherein, the reaction pipeline of the microfluidic tubular reactor contains novel internal components, and a novel microfluidic dynamic reactor is used. In the preparation method of prochloraz of the present invention, microfluidic technology is used and a new microfluidic device is matched, with high yield, few by-products, short reaction time, small equipment footprint, safety and energy saving, etc., and it is suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of pesticide and insecticide prochloraz, and particularly relates to a method and device for preparing prochloraz by adopting microfluidic field reaction technology. Background Art

[0002] Prochloraz, chemically named N-propyl-N-(2,4,6-trichlorophenoxyethyl)-1H-imidazole-1-carboxamide, is a highly effective broad-spectrum imidazole fungicide. It was synthesized by Boots., Ltd. in the UK in 1977 and launched on the market in 1977. It works by inhibiting the biosynthesis of sterols, has a systemic conduction effect in plants, has strong penetration, good rapidity, high activity, a broad fungicide spectrum, a long lasting effect, and a low dosage. It has both protective, therapeutic and eradication effects. It is widely used in crop production.

[0003] There are many methods for synthesizing prochloraz, and the process routes are complicated. Initially, for example, US Patent US 3991071 used dibromoethane as the raw material, which was highly toxic, expensive, and a carcinogen. At the end of the last century, domestic manufacturers developed the synthesis of prochloraz using dichloroethane and 2,4,6-trichlorophenol as the main raw materials. For example, patents CN 1246473 and CN101402608A both introduced it. At present, this route is basically adopted in China, and the final product prochloraz is obtained by etherification of 2,4,6-trichlorophenol and 1,2-dichloroethane in the presence of sodium hydroxide, amination with n-propylamine, chlorination, and condensation. However, the autoclave process has the disadvantages of long reaction time, high energy consumption, and low purity. As the domestic prochloraz market share continues to increase, the export volume of technical drugs increases year by year, and the demand for high-purity prochloraz technical drugs increases. Therefore, it is of great significance to develop a high-yield, low-cost, continuous flow production process for prochloraz. Summary of the invention

[0004] Purpose of the invention: The present invention provides a method and device for preparing prochloraz using microfluidic field reaction technology, which changes the autoclave process of prochloraz into a microfluidic field process and matches new internal components and a microfluidic field dynamic reactor. The method has short reaction time, low energy consumption, high yield and is suitable for industrial continuous production.

[0005] Technical solution: In order to achieve the above-mentioned invention object, the present invention adopts the following technical solution:

[0006] A method for preparing prochloraz using microfluidic field reaction technology comprises the following steps:

[0007] (1) dissolving 2,4,6-trichlorophenol with liquid alkali and then pumping the mixture with excess 1,2-dichloroethane into a micro-flow field tubular reactor with internal components in a reaction pipeline, and subjecting the reaction to high temperature to obtain 2,4,6-trichlorophenoxyethyl chloride;

[0008] (2) dissolving 2,4,6-trichlorophenoxyethyl chloride in n-propylamine, pumping a single stream into a microfluidic tubular reactor with internal components in a reaction pipeline, and reacting under high temperature and high pressure to obtain N-(2,4,6-trichlorophenoxyethyl)propylamine;

[0009] (3) N-(2,4,6-trichlorophenoxyethyl)propylamine is dissolved in an organic solvent, the solid light solution is dissolved in an organic solvent and triethylamine is added, the two solutions are pumped into a microfluidic dynamic reactor respectively, the solid-liquid mixture is squeezed out after the reaction, filtered, and the filtrate is directly used in the next step;.

[0010] (4) dissolving imidazole in an organic solvent, adding triethylamine, and pumping the imidazole and the filtrate obtained in step (3) into a microfluidic field dynamic reactor respectively. After the reaction, the solid-liquid mixture is squeezed out, filtered, washed, and desolventized to obtain pure N-propyl-N-(2,4,6-trichlorophenoxyethyl)-1H-imidazole-1-carboxamide (imidazole).

[0011] The synthetic route of prochloraz is as follows:

[0012]

[0013] As a preference:

[0014] In step (1), the two phases are immiscible. As a microchannel reaction, a certain linear velocity is ensured to enhance the mixing of the two phases, and the preferred fluid linear velocity is above 0.1 m / s; the high temperature is 140-170°C, and the preferred temperature is 160°C.

[0015] In step (1), in the alkali solution dissolving 2,4,6-trichlorophenol, the equivalent ratio of sodium hydroxide to 2,4,6-trichlorophenol is 1:1 to 1:1.5, and the mass ratio of water to 2,4,6-trichlorophenol is 1:1.5 to 1:2. Preferably, 2,4,6-trichlorophenol: sodium hydroxide: water = 1 eq: 1.0 eq: 1.5 vol.

[0016] In step (1), the equivalent ratio of 1,2-dichloroethane to 2,4,6-trichlorophenol is 4:1 to 8:1. Preferably, the equivalent ratio of 1,2-dichloroethane to 2,4,6-trichlorophenol is 4:1.

[0017] In step (1), the reaction solution stays in the reactor for 5 to 20 minutes, preferably 8 minutes.

[0018] The reaction in step (2) is amination of 2,4,6-trichlorophenoxyethyl chloride directly in n-propylamine, which is both a solvent and a reagent, and high temperature and high pressure promote the reaction. Considering safety factors, the high temperature is 120-140° C., preferably 130° C., and the pressure is 0.9 MPa-1.5 MPa, preferably 1.2 MPa.

[0019] In step (2), the equivalent ratio of 2,4,6-trichlorophenoxyethyl chloride to n-propylamine is 1:5 to 1:10, preferably 1:6. In step (2), the residence time of the reaction solution in the reactor is 5 to 20 minutes, preferably 10 minutes.

[0020] In step (3), triethylamine is used as an acid binding agent to promote the reaction. However, in order to generate triethylamine hydrochloride solid during the reaction, a microfluidic field dynamic reactor is required to extrude the solid-liquid mixed reaction solution.

[0021] In step (3), the equivalent ratio of N-(2,4,6-trichlorophenoxyethyl)propylamine to solid light is 1:0.3-1:0.4, preferably 1:0.36; the amount of triethylamine is 1.0-1.1 eq, preferably 1.0 eq; and the reaction temperature is 80-100°C, preferably 85°C.

[0022] In step (3), the reaction solution stays in the reactor for 2 to 10 minutes, preferably 2.5 minutes.

[0023] In step (4), triethylamine is also used as an acid binding agent. During the reaction, triethylamine hydrochloride solid is produced. Therefore, a microfluidic dynamic reactor is used to extrude the solid-liquid mixed reaction liquid.

[0024] In step (4), the imidazole equivalent is 1.0 to 1.1 eq, preferably 1.0 eq; the triethylamine equivalent is 1.0 to 1.1 eq, preferably 1.0 eq; and the reaction temperature is 80 to 100° C., preferably 85° C.

[0025] In step (4), the reaction solution stays in the reactor for 5 to 20 minutes, preferably for 10 minutes.

[0026] Among them, the internal components can adopt new internal components, which have better mass transfer and heat transfer effects, and greatly improve the reaction rate and product conversion rate.

[0027] The present invention also provides an internal component for preparing prochloraz using microfluidic reaction technology, comprising an integrated grid structure and a spiral structure, wherein the grid structure and the spiral structure are arranged at intervals, and the grid structure is formed by cross-connecting strip-shaped plate-type unit sheets at a certain angle. When used, the internal component is placed in a reaction tube, and the tube and the internal component are welded at the ends. The working principle is to use two different structures in the internal component to make the fluid turbulence more intense, thereby increasing its mass transfer and heat transfer effect and improving the reaction efficiency.

[0028] The present invention also provides a microfluidic field dynamic reactor for preparing prochloraz, comprising a transmission motor, a reducer and a screw reactor, wherein a stirring paddle is arranged inside the screw reactor, a heat exchange jacket is arranged outside the screw reactor, and a spiral blade is arranged in the middle section of the stirring paddle; the working principle is to use the spiral blade to push the material axially, and at the same time, a stirring blade is added in the middle to stir the material during the transmission process, and the spiral is changed to straight teeth at the discharge port to make the material discharge smoother.

[0029] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0030] (1) The preparation method of prochloraz of the present invention has short reaction time, low energy consumption, short production cycle and high efficiency;

[0031] (2) In the preparation method of prochloraz of the present invention, several steps of the reaction are high-temperature and high-pressure reactions, and the use of a microfluidic device is safer;

[0032] (3) The preparation method of prochloraz of the present invention uses a new internal component and a microfluidic field dynamic reactor, which has few side reactions and high yield. At the same time, the equipment occupies a small area, which is conducive to reducing costs and improving production capacity.

[0033] (4) The preparation method of prochloraz of the present invention can be produced in a continuous flow, thereby improving the degree of automation and reducing labor costs and the uncertainty of manual operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a diagram of the microfluidic field tubular reactor equipment used in the present invention.

[0035] Figure 2 This is a schematic diagram of the structure of the internal components of the microfluidic field used in the present invention and a partial enlarged diagram.

[0036] Figure 3 This is a schematic diagram of the structure of the microfluidic field dynamic reactor used in the present invention.

[0037] Figure 4 It is a schematic diagram of the structure of the screw reactor in the microfluidic field dynamic reactor used in the present invention.

[0038] Figure 5 This is a real shot of the microfluidic field dynamic reactor equipment used in the present invention.

[0039] Figure 6 The H NMR spectrum of intermediate 1 2,4,6-trichlorophenoxyethyl chloride in Example 1 is 1 H-NMR (DMSO-d6, 400 MHz).

[0040] Figure 7 This is the H NMR spectrum of the intermediate 2N-(2,4,6-trichlorophenoxyethyl)propylamine in Example 1 1H-NMR (DMSO-d6, 400 MHz).

[0041] Figure 8 The NMR hydrogen spectrum of the reaction solution (containing triethylamine) of the intermediate 3N-(2,4,6-trichlorophenoxyethyl) propylcarbamoyl chloride of Example 1 1 H-NMR (DMSO-d6, 400 MHz).

[0042] Fig. 9 The H NMR spectrum of the final product prochloraz prepared in Example 1 of the present invention 1 H-NMR (DMSO-d6, 400 MHz).

[0043] Fig.10 The figure is a whole process flow chart of the method of the present invention. DETAILED DESCRIPTION

[0044] The specific embodiments of the present invention are described in further detail below in conjunction with the accompanying drawings and examples. However, it will be appreciated by those skilled in the art that the following examples are only for describing the conditions and are carried out under normal conditions or the conditions recommended by the manufacturer. The reagents or instruments used that do not indicate the manufacturer are all conventional products that can be purchased commercially.

[0045] The microfluidic tubular reactors in steps (1) and (2) of the following examples all use novel SXK internal components, the structure of which is as follows: Figure 2 As shown, it includes an integrated grid structure 11 and a spiral structure 12, the grid structure 11 and the spiral structure 12 are arranged at intervals, and the grid structure 11 is formed by cross-connecting strip plate units at a certain angle. The internal component is placed in the reaction tube, and the tube and the internal component are welded at the end.

[0046] The microfluidic field dynamic reactors in steps (3) and (4) of the following examples all adopt a novel microfluidic field dynamic reactor, the structure of which is as follows: Figure 3 , 4 As shown in 5 , it includes a transmission motor 21 , a reducer 22 and a screw reactor 23 . A stirring paddle 230 is arranged inside the screw reactor 23 , a heat exchange jacket is arranged outside the screw reactor 23 , and a spiral blade 231 is arranged in the middle section of the stirring paddle 230 .

[0047] Example 1

[0048] The microfluidic field preparation method of prochloraz comprises the following steps:

[0049] (1) 2,4,6-Trichlorophenol (500 g), sodium hydroxide solid (121.6 g), and water (750 mL) were prepared into a homogeneous solution at a ratio of 1 eq: 1 eq: 1.5 vol, and the mixture was pumped into a microfluidic tubular reactor (with SXK internal components) with 1,2-dichloroethane (1002.4 g, 4 eq) using metering pumps. The mixture was reacted at 160° C. for 8 minutes at a reactor pressure of 1.4 MPa. The resulting reaction solution was cooled and separated to obtain a crude product of 2,4,6-trichlorophenoxyethyl chloride, which was purified by vacuum distillation to obtain 628.7 g of a pure product with a yield of 95.5%.

[0050] (2) Pure 2,4,6-trichlorophenoxyethyl chloride (500 g, 1 eq) and n-propylamine (682.2 g, 6 eq) were stirred to form a solution and pumped into a microfluidic tubular reactor (with SXK internal components) in a single stream for reaction at 130° C. for a residence time of 10 min. The pressure in the reactor was 1.2 MPa. The excess n-propylamine in the outflowing reaction solution was evaporated with alkali, and the inorganic salt was removed by filtration to obtain 513.7 g of pure N-(2,4,6-trichlorophenoxyethyl)propylamine with a yield of 94.5%. The product was dried and then used in the next step.

[0051] (3) N-(2,4,6-trichlorophenoxyethyl)propylamine (500 g, 1 eq) was dissolved in 1,2-dichloroethane (2000 mL, 4 vol) as solvent A, and solid light (189.0 g, 0.36 eq) was dissolved in 1,2-dichloroethane (2000 mL, 4 vol) and triethylamine (179.0 g, 1 eq) was added as solvent B. They were pumped into the microfluidic field dynamic reactor respectively, with a flow rate ratio of A:B of 1:1. The reaction was carried out at 85°C with a residence time of 2.5 min. After the reaction, the solid-liquid mixture was squeezed out, the triethylamine hydrochloride was filtered out, and it was directly used in the next step.

[0052] (4) Imidazole (120.5 g, 1 eq) was dissolved in 1,2-dichloroethane (2000 mL, 4 vol), and triethylamine (179 g, 1 eq) was added as solution A and the above filtrate as solution B, and the mixture was pumped into the microfluidic field dynamic reactor by metering pumps in two streams, with the flow rate ratio of A:B being 1:2. The reaction was carried out at 85°C, and the residence time was 10 min. After the reaction, the solid-liquid mixture was squeezed out, and the triethylamine hydrochloride was removed by filtration. The mixture was washed with acid water and alkaline water respectively, and then desolventized to obtain pure N-propyl-N-(2,4,6-trichlorophenoxyethyl)-1H-imidazole-1-carboxamide (imidazole, 629.1 g). The yield of the two steps 3 and 4 was 94.4%. The total yield of the four-step reaction was 85.2%, and the purity was 99.2%.

[0053] Example 2

[0054] The microfluidic field preparation method of prochloraz comprises the following steps:

[0055] (1) 2,4,6-trichlorophenol (700 g), sodium hydroxide solid (170.3 g), water (1050 mL) were prepared into a solution in a ratio of 1 eq: 1 eq: 1.5 vol and 1,2-dichloroethane (1403.4 g, 4 eq) were pumped into a microfluidic tubular reactor (with SXK internal components) using metering pumps, and reacted at 158° C. for 10 minutes at a reactor pressure of 1.2 MPa. The resulting reaction solution was cooled and separated to obtain a crude product of 2,4,6-trichlorophenoxyethyl chloride, which was purified by vacuum distillation to obtain 877.4 g of a pure product with a yield of 95.2%.

[0056] (2) Pure 2,4,6-trichlorophenoxyethyl chloride (700 g, 1 eq) and n-propylamine (955.1 g, 6 eq) were stirred to form a solution and pumped into a microfluidic tubular reactor (with SXK internal components) in a single stream for reaction at 125° C. for 8 min. The pressure in the reactor was 1.2 MPa. The excess n-propylamine in the outflowing reaction solution was evaporated with alkali, and the inorganic salt was removed by filtration to obtain 710.8 g of pure N-(2,4,6-trichlorophenoxyethyl)propylamine with a yield of 93.4%. The product was dried and then used in the next step.

[0057] (3) N-(2,4,6-trichlorophenoxyethyl)propylamine (700 g, 1 eq) was dissolved in 1,2-dichloroethane (2800 mL, 4 vol) as solvent A, and solid light (264.6 g, 0.36 eq) was dissolved in 1,2-dichloroethane (2800 mL, 4 vol) and triethylamine (250.6 g, 1 eq) was added as solvent B. They were pumped into the microfluidic field dynamic reactor respectively, with a flow rate ratio of A:B of 1:1. The reaction was carried out at 85°C with a residence time of 3 min. After the reaction, the solid-liquid mixture was squeezed out, the triethylamine hydrochloride was filtered out, and it was directly used in the next step.

[0058] (4) Imidazole (168.7 g, 1 eq) was dissolved in 1,2-dichloroethane (2800 mL, 4 vol), and triethylamine (250.6 g, 1 eq) was added as solution A and the above filtrate as solution B, and the mixture was pumped into the microfluidic field dynamic reactor by metering pumps in two streams, with the flow rate ratio of A:B being 1:2. The reaction was carried out at 85°C, and the residence time was 8 min. After the reaction, the solid-liquid mixture was squeezed out, and the triethylamine hydrochloride was removed by filtration. The mixture was washed with acid water and alkaline water respectively, and then desolventized to obtain pure N-propyl-N-(2,4,6-trichlorophenoxyethyl)-1H-imidazole-1-carboxamide (imidazole, 629.1 g). The yield of the two steps 3 and 4 was 93.6%. The total yield of the four-step reaction was 83.2%, and the purity was 99.4%.

[0059] Example 3

[0060] The microfluidic field preparation method of prochloraz comprises the following steps:

[0061] (1) 2,4,6-Trichlorophenol (1000 g), sodium hydroxide solid (243.6 g), water (1500 mL), prepared into a solution in the ratio of 1 eq: 1 eq: 1.5 vol, and 1,2-dichloroethane (2004.8 g, 4 eq), respectively, were pumped into a microfluidic tubular reactor (with SXK internal components) by metering pumps, reacted at 150° C., with a residence time of 10 minutes and a reactor pressure of 1.3 MPa. The resulting reaction solution was cooled and separated to obtain a crude product of 2,4,6-trichlorophenoxyethyl chloride, which was purified by vacuum distillation to obtain 1252.1 g of a pure product with a yield of 95.1%.

[0062] (2) Pure 2,4,6-trichlorophenoxyethyl chloride (1000 g, 1 eq) and n-propylamine (1364.4 g, 6 eq) were stirred to form a solution and pumped into a microfluidic tubular reactor (with SXK internal components) in a single stream for reaction at 130° C. for a residence time of 8 min. The pressure in the reactor was 1.3 MPa. The excess n-propylamine in the outflowing reaction solution was evaporated with alkali, and the inorganic salt was removed by filtration to obtain 1022.0 g of pure N-(2,4,6-trichlorophenoxyethyl)propylamine with a yield of 94.0%. The product was dried and then used in the next step.

[0063] (3) N-(2,4,6-trichlorophenoxyethyl)propylamine (1000 g, 1 eq) was dissolved in 1,2-dichloroethane (4000 mL, 4 vol) as solvent A, and solid light (378.0 g, 0.36 eq) was dissolved in 1,2-dichloroethane (4000 mL, 4 vol) and triethylamine (358.0 g, 1 eq) was added as solvent B. They were pumped into the microfluidic field dynamic reactor respectively, with a flow rate ratio of A:B of 1:1. The reaction was carried out at 85°C with a residence time of 3 min. After the reaction, the solid-liquid mixture was squeezed out, the triethylamine hydrochloride was filtered out, and it was directly used in the next step.

[0064] (4) Imidazole (241.0 g, 1 eq) was dissolved in 1,2-dichloroethane (4000 mL, 4 vol), and triethylamine (358.0 g, 1 eq) was added as solution A and the above filtrate as solution B, and the mixture was pumped into the microfluidic field dynamic reactor by metering pumps in two streams, with the flow rate ratio of A:B being 1:2. The reaction was carried out at 85°C, and the residence time was 10 min. After the reaction, the solid-liquid mixture was squeezed out, and the triethylamine hydrochloride was removed by filtration. The mixture was washed with acid water and alkaline water respectively, and then desolventized to obtain pure N-propyl-N-(2,4,6-trichlorophenoxyethyl)-1H-imidazole-1-carboxamide (imidazole, 1255.5 g). The yield of the two steps 3 and 4 was 94.2%. The total yield of the four-step reaction was 84.2%, and the purity was 98.7%.

[0065] Comparative Example 1:

[0066] The preparation method of intermittent prochloraz comprises the following steps:

[0067] (1) 500 g of 2,4,6-trichlorophenol, 700 g of 1,2-dichloroethane, and 350 g of 30% concentrated alkali were added to a 3L reaction bottle, and the mixture was sealed and heated under stirring. The temperature was controlled at 130-135°C and the reaction was carried out for 10 hours. After cooling and standing, the water layer was separated, and the oil phase was washed with water and vacuum distilled to obtain 570 g of pure 2,4,6-trichlorophenoxyethyl chloride, with a yield of 86.6%.

[0068] (2) 570g of propylamine and 848g of propylamine were added to a 3L reaction bottle, and the temperature was kept at 95-100°C and refluxed for 11 hours. When the temperature returned to room temperature, the propylamine was recovered by heating and distillation, and the insoluble matter was removed by suction filtration to obtain 523g of N-(2,4,6-trichlorophenoxyethyl)propylamine, with a yield of 84.4%.

[0069] (3) 500g of toluene was added to a 1L reaction bottle, and about 190g of solid phosgene was slowly added under stirring. The mixture was stirred for 30 minutes until it was completely dissolved to obtain a solid phosgene toluene solution. 850g of toluene and 523g of N-(2,4,6-trichlorophenoxyethyl)propylamine were added to another 3L reaction bottle. A tail gas absorption device was connected to the reaction bottle, and the temperature was raised by stirring. When the temperature reached 90°C, the solid phosgene toluene solution was added dropwise. The dropping speed was controlled so that the temperature was controlled at 110-115°C. The solution was added dropwise in about 4 hours. After the addition was completed, the solution was kept warm for 0.5h to obtain a toluene solution of 1850g of N-(2,4,6-trichlorophenoxyethyl)propylcarbamoyl chloride.

[0070] (4) Add 127.5 g of imidazole and 205 g of triethylamine to a 3 L reaction bottle, stir and heat to 85 ° C, and drop N-(2,4,6-trichlorophenoxyethyl) alanylcarbamoyl chloride in toluene. Control the dropping speed to keep the temperature at 80-85 ° C, and drip it in about 3 hours. After dripping, keep warm for 3 hours. Cool to room temperature, remove triethylamine salt by suction filtration, remove the solvent by rotary evaporation, and then heat to 120 ° C. Filter out insoluble matter while hot to obtain pure N-propyl-N-(2,4,6-trichlorophenoxyethyl)-1H-imidazole-1-carboxamide (imidazole, 628 g), with a purity of 94.6% and a total yield of 65.8% in four steps.

[0071] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing prochloraz using microfluidic field reaction technology, characterized in that: The steps include: (1) using liquid alkali to dissolve 2,4,6-trichlorophenol and an excess of 1,2-dichloroethane, and pumping them into a microfluidic tubular reactor with internal components in a reaction pipeline, and subjecting them to a high-temperature reaction to obtain 2,4,6-trichlorophenoxyethyl chloride; wherein, in the 2,4,6-trichlorophenol dissolved in liquid alkali, the equivalent ratio of sodium hydroxide to 2,4,6-trichlorophenol is 1:1 to 1:1.5, the mass ratio of water to 2,4,6-trichlorophenol is 1:1.5 to 1:2; the equivalent ratio of 1,2-dichloroethane to 2,4,6-trichlorophenol is 4:1 to 8:1; the high-temperature reaction is carried out at a temperature of 140 to 170° C., and the residence time of the reaction liquid in the reactor is 5 to 20 minutes; (2) dissolving 2,4,6-trichlorophenoxyethyl chloride in n-propylamine, pumping a single stream into a microfluidic tubular reactor with internal components in a reaction pipeline, and reacting under high temperature and high pressure to obtain N-(2,4,6-trichlorophenoxyethyl)propylamine; the equivalent ratio of 2,4,6-trichlorophenoxyethyl chloride to n-propylamine is 1:5 to 1:10; the reaction under high temperature and high pressure has a temperature of 120 to 140° C. and a pressure of 0.9 to 1.5 MPa; and the reaction solution stays in the reactor for 5 to 20 minutes; (3) N-(2,4,6-trichlorophenoxyethyl)propylamine is dissolved in an organic solvent, and the solid light solution is dissolved in an organic solvent and triethylamine is added. The two solutions are pumped into a microfluidic field dynamic reactor respectively. After the reaction, the solid-liquid mixture is squeezed out and filtered. The filtrate is directly used in the next step; the equivalent ratio of N-(2,4,6-trichlorophenoxyethyl)propylamine to the solid light is 1:0.3 to 1:0.4, and the amount of triethylamine is 1.0 to 1.1 eq; the reaction temperature is 80 to 100° C., and the reaction solution stays in the reactor for 2 to 10 minutes (4) dissolving imidazole in an organic solvent, adding triethylamine, and pumping the mixture and the filtrate obtained in step (3) into a microfluidic field dynamic reactor respectively. After the reaction, the solid-liquid mixture is squeezed out, filtered, washed, and then desolventized to obtain pure N-propyl-N-(2,4,6-trichlorophenoxyethyl)-1H-imidazole-1-carboxamide; the imidazole equivalent is 1.0 to 1.1 eq, and the triethylamine equivalent is 1.0 to 1.1 eq; the reaction temperature is 80 to 100° C., and the reaction solution stays in the reactor for 5 to 20 minutes. The internal components in steps (1) and (2) include an integrated grid structure (11) and a spiral structure (12), wherein the grid structure (11) and the spiral structure (12) are arranged at intervals, and the grid structure (11) is formed by cross-connecting strip-shaped plate-type unit sheets at a certain angle.

2. An internal component for preparing prochloraz using microfluidic field reaction technology, characterized in that: The internal component comprises an integrated grid structure (11) and a spiral structure (12), wherein the grid structure (11) and the spiral structure (12) are arranged at intervals, and the grid structure (11) is formed by cross-connecting strip-shaped plate-type unit pieces at a certain angle.

Images