Synthesis method of pesticide flupyradifurone
By directly synthesizing flupyrfuranone through a one-step reaction, the problem of low yield caused by the instability of intermediates is solved, and an efficient and simplified synthesis process is achieved, which improves the yield and ease of operation of flupyrfuranone.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-16
- Publication Date
- 2026-04-07
AI Technical Summary
Existing methods for synthesizing flupyrfuranone suffer from unstable intermediates, leading to low yields.
Fluoropyrfuranone was directly synthesized in one step by reacting N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 2(5H)-furanone, and a catalyst under specific conditions, avoiding unstable intermediates. Catalysts such as lithium tert-butoxide, potassium phosphate, or potassium carbonate were used.
It improves the synthesis yield of flupyrfuranone, simplifies the synthesis steps, reduces the difficulty of operation, and makes the raw materials readily available, with strong applicability and flexibility.
Smart Images
Figure CN121800768A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of pesticide chemical synthesis technology, and in particular relates to a method for synthesizing the pesticide flupyrfuranone. Background Technology
[0002] Flupyrrolidone is a neonicotinoid insecticide that acts on acetylcholine receptors in insects, addressing pest resistance through a unique mechanism of action while reducing acute toxicity to bees. It is mainly used to control piercing-sucking pests in vegetables, fruit trees, and field crops.
[0003] The main methods currently reported for the synthesis of flupyrfuranone are: 1. Starting with ethyl 4-chloroacetoacetate, the target product flupyrofuranone was obtained through a four-step reaction via a terfenic acid intermediate. However, the terfenic acid intermediate was unstable, and the yield of the last step was only 52%, resulting in a low yield for the entire synthetic route.
[0004] 2. The reaction of 2-chloro-5-chloromethylpyridine with difluoroethylamine to obtain an intermediate, followed by reaction with terfenic acid to obtain flupyrofuranone, also suffers from the instability of the terfenic acid intermediate and low yield. Summary of the Invention
[0005] In view of this, the present invention aims to provide a method for synthesizing the pesticide flupyrfuranone, in order to solve at least one technical problem in the background art.
[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A method for synthesizing the pesticide flupyrfuranone includes the following steps: at room temperature, solvent, N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 2(5H)-furanone and catalyst are stirred, and the mixture is stirred at 40~50℃ until the reaction is complete to obtain a reaction system. After post-treatment of the reaction system, flupyrfuranone is obtained. Furthermore, the molar ratio of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 2(5H)-furanone to the catalyst is 1:(2~3):(1~3).
[0007] Furthermore, the molar ratio of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 2(5H)-furanone to the catalyst is 1:2.5:2.
[0008] Furthermore, the catalyst is any one of lithium tert-butoxide, potassium phosphate, or potassium carbonate.
[0009] Furthermore, the mass-to-volume ratio of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine to the organic solvent is 1:5~10.
[0010] Furthermore, the mass-to-volume ratio of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine to the organic solvent is 1:10.
[0011] Furthermore, the organic solvent is selected from one or more of tetrahydrofuran, ethylene glycol dimethyl ether, and 1,4-dioxane.
[0012] Further, the post-processing includes filtering the reaction system to remove insoluble matter, washing with water, extracting to obtain an organic phase, concentrating the organic phase under reduced pressure to recover the solvent and obtain a mixture, and then recrystallizing the mixture to obtain flupyrfuranone.
[0013] Furthermore, methanol was used as the solvent for recrystallization.
[0014] Compared with existing technologies, the method for synthesizing the pesticide flupyrfuranone described in this invention has the following advantages: 1. The method for synthesizing the pesticide flupyrfuranone described in this invention uses readily available raw material 2(5H)-furanone, and the reaction can stably and efficiently synthesize flupyrfuranone, avoiding unstable intermediates in existing processes, and achieving good yield.
[0015] 2. This invention uses a one-step reaction to directly synthesize flupyrfuranone from stable raw materials, avoiding the complex process of multiple reactions and the use of unstable intermediates in existing processes, greatly simplifying the synthesis steps and reducing the difficulty of operation.
[0016] 3. This invention can use a variety of catalysts such as potassium carbonate, lithium tert-butoxide, and potassium phosphate, and has good applicability and flexibility, making it easy to optimize according to actual production conditions. Attached Figure Description
[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is the HPLC chromatogram of flupyrfuranone described in Example 1 of the present invention. Detailed Implementation
[0018] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.
[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0020] Example 1 At room temperature, 20.6 mL of tetrahydrofuran, 2.07 g of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 2.10 g of 2(5H)-furanone, and 2.76 g of potassium carbonate were added sequentially to a reaction vessel and stirred until dissolved. The mixture was then stirred at 40–50 °C until complete. After complete reaction, the reaction system was filtered to remove insoluble matter, and the tetrahydrofuran was concentrated and recovered. The tetrahydrofuran was then dissolved in ethyl acetate, washed with water, and extracted to obtain the organic phase. The organic phase was concentrated under reduced pressure to recover ethyl acetate, yielding a mixture. The mixture was recrystallized from methanol to obtain 2.34 g of the target product, flupyrofuranone, with a yield of 81%.
[0021] Example 2 At room temperature, 10.4 mL of ethylene glycol dimethyl ether, 2.07 g of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 1.68 g of 2(5H)-furanone, and 4.15 g of potassium carbonate were added sequentially to a reaction vessel and stirred until dissolved. The mixture was then stirred at 40–50 °C until complete. After complete reaction, the reaction system was filtered to remove insoluble matter, and the ethylene glycol dimethyl ether was concentrated and recovered. The solution was then dissolved in ethyl acetate, washed with water, and extracted to obtain the organic phase. The organic phase was concentrated under reduced pressure to recover ethyl acetate, yielding a mixture. The mixture was recrystallized from methanol to obtain 2.25 g of the target product, flupyrofuranone, with a yield of 78%.
[0022] Example 3 At room temperature, 16.5 mL of 1,4-dioxane, 2.07 g of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 2.52 g of 2(5H)-furanone, and 2.07 g of potassium carbonate were added sequentially to a reaction vessel and stirred until dissolved. The mixture was then stirred at 40–50 °C until the reaction was complete. After the reaction was complete, the reaction system was filtered to remove insoluble matter, and 1,4-dioxane was concentrated and recovered. The 1,4-dioxane was then dissolved in ethyl acetate, washed with water, and extracted to obtain the organic phase. The organic phase was concentrated under reduced pressure to recover ethyl acetate, yielding a mixture. The mixture was recrystallized from methanol to obtain 2.17 g of the target product, flupyrfuranone, with a yield of 75%.
[0023] Example 4 At room temperature, 20.6 mL of tetrahydrofuran, 2.07 g of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 2.10 g of 2(5H)-furanone, and 1.60 g of lithium tert-butoxide were added sequentially to a reaction vessel and stirred until dissolved. The mixture was then stirred at 40–50 °C until the reaction was complete. After the reaction was complete, the reaction system was filtered to remove insoluble matter, and the tetrahydrofuran was concentrated and recovered. The tetrahydrofuran was then dissolved in ethyl acetate, washed with water, and extracted to obtain the organic phase. The organic phase was concentrated under reduced pressure to recover ethyl acetate, yielding a mixture. The mixture was recrystallized from methanol to obtain 1.82 g of the target product, flupyrofuranone, with a yield of 63%.
[0024] Example 5 At room temperature, 20.6 mL of tetrahydrofuran, 2.07 g of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 1.68 g of 2(5H)-furanone, and 4.24 g of potassium phosphate were added sequentially to a reaction vessel and stirred until dissolved. The mixture was then stirred at 40–50 °C until complete. After complete reaction, the reaction system was filtered to remove insoluble matter, and the tetrahydrofuran was concentrated and recovered. The tetrahydrofuran was then dissolved in ethyl acetate, washed with water, and extracted to obtain the organic phase. The organic phase was concentrated under reduced pressure to recover ethyl acetate, yielding a mixture. The mixture was recrystallized from methanol to obtain 2.02 g of the target product, flupyrofuranone, with a yield of 70%.
[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for synthesizing the pesticide flupyrfuranone, characterized in that: The process includes the following steps: at room temperature, solvent, N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 2(5H)-furanone and catalyst are stirred until the reaction is complete at 40~50℃ to obtain the reaction system. After post-treatment of the reaction system, flupyrfuranone is obtained.
2. The method for synthesizing the pesticide flupyrfuranone according to claim 1, characterized in that: The molar ratio of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 2(5H)-furanone, and the catalyst is 1:(2~3):(1~3).
3. The method for synthesizing the pesticide flupyrfuranone according to claim 1, characterized in that: The molar ratio of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine, 2(5H)-furanone to the catalyst is 1:2.5:
2.
4. The method for synthesizing the pesticide flupyrfuranone according to claim 1, characterized in that: The catalyst is any one of lithium tert-butoxide, potassium phosphate, or potassium carbonate.
5. The method for synthesizing the pesticide flupyrfuranone according to claim 1, characterized in that: The mass-to-volume ratio of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine to the organic solvent is 1:5~10.
6. The method for synthesizing the pesticide flupyrflurane according to claim 1, characterized in that: The mass-to-volume ratio of N-((6-chloropyridin-3-yl)methyl)-2,2-difluoroethylamine to the organic solvent is 1:
10.
7. The method for synthesizing the pesticide flupyrfuranone according to claim 1, characterized in that: The organic solvent is selected from one or more of tetrahydrofuran, ethylene glycol dimethyl ether, and 1,4-dioxane.
8. The method for synthesizing the pesticide flupyrflurane according to claim 1, characterized in that: Post-processing includes filtering the reaction system to remove insoluble matter, washing with water, extracting to obtain an organic phase, concentrating the organic phase under reduced pressure to recover the solvent and obtain a mixture, and recrystallizing the mixture to obtain flupyrfuranone.