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CN-121974865-A - Synthetic method of isoxazole compound under visible light catalysis condition

CN121974865ACN 121974865 ACN121974865 ACN 121974865ACN-121974865-A

Abstract

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing isoxazole compounds under the condition of visible light catalysis. The method comprises the steps of dissolving a compound 1 in 1, 2-dichloroethane, adding tert-butyl nitrite, bromoform, alkali and a photocatalyst, irradiating with visible light in an inert gas environment, stirring at room temperature for reaction, removing a solvent under reduced pressure after the reaction is finished, and purifying a crude product by a silica gel column to obtain the isoxazole compound. The invention develops a brand-new method for preparing the isoxazole compound by visible light catalysis, which not only avoids the conditions of high temperature and high pressure in the traditional synthesis method and obviously reduces energy consumption and environmental pollution, but also effectively improves the yield of the isoxazole compound by regulating and controlling reaction conditions and optimizing raw material selection and proportion.

Inventors

  • ZHANG JIANTAO
  • JIANG YANFU
  • ZHANG XIAOLI
  • LIU WEIBING

Assignees

  • 广东石油化工学院

Dates

Publication Date
20260505
Application Date
20260128

Claims (10)

  1. 1. The synthesis method of the isoxazole compound under the visible light catalysis condition is characterized by comprising the following steps: Compound 1 is dissolved in 1, 2-dichloroethane, then tert-butyl nitrite, bromoform, alkali and photocatalyst are added, the mixture is irradiated with visible light and stirred at room temperature for reaction in an inert gas environment, after the reaction is completed, the solvent is removed under reduced pressure, and then the crude product is subjected to silica gel column purification to obtain the product, namely the isoxazole compound.
  2. 2. The method for synthesizing the isoxazole compound under the visible light catalysis condition according to claim 1, wherein the compound 1 is any one of the following structural formulas: 。
  3. 3. The method for synthesizing the isoxazole compound under the visible light catalysis condition according to claim 1, wherein the molar ratio of the compound 1 to the tert-butyl nitrite to the tribromomethane to the alkali is 1:1-3:4:4-6.
  4. 4. The method for synthesizing the isoxazole compound under the visible light catalytic condition according to claim 3, wherein the molar ratio of the compound 1 to the tert-butyl nitrite to the tribromomethane to the alkali is 1:3:4:6.
  5. 5. The method for synthesizing the isoxazole compound under the visible light catalysis condition according to claim 1, wherein the amount of the photocatalyst is 1-5% of the 1 molar amount of the compound.
  6. 6. The method for synthesizing an isoxazole compound under a visible light catalytic condition according to claim 5, wherein the amount of the photocatalyst is 2% of the 1 molar amount of the compound.
  7. 7. The method for synthesizing the isoxazole compound under the visible light catalytic condition according to claim 1, wherein the base is any one of triethylamine, DBU, triethylenediamine and diisopropylethylamine.
  8. 8. The method for synthesizing an isoxazole compound under a visible light catalytic condition according to claim 1, wherein the photocatalyst is any one of [Ir(dtbbpy)(ppy) 2 ]PF 6 、Na 2 -Eosin Y、4DPAIPN、Ru(phen) 3 (PF 6 ) 2 .
  9. 9. The method for synthesizing the isoxazole compound under the visible light catalysis condition according to claim 1, wherein the visible light irradiation is performed by using a blue LED light source with the power of 35W.
  10. 10. The method for synthesizing isoxazole compounds under visible light catalytic conditions according to claim 1, wherein the stirring reaction time is 12 hours, and the inert gas is N 2 .

Description

Synthetic method of isoxazole compound under visible light catalysis condition Technical Field The invention belongs to the technical field of organic synthesis, and particularly relates to a method for synthesizing isoxazole compounds under the condition of visible light catalysis. Background Isoxazoles exhibit a broad range of biological activity and chemical stability due to their unique five-membered ring structure (containing one oxygen atom and one nitrogen atom), making them of irreplaceable importance in the fields of medicine, agriculture, material science, etc. In the field of medicine, isoxazoles and derivatives thereof show remarkable biological activity and become important basic stones for drug development. For example, certain isoxazole derivatives have hypoglycemic, analgesic, anti-inflammatory and antibacterial properties and are useful in the treatment of diabetes, chronic pain and infectious diseases. In addition, they can inhibit the replication of AIDS virus, and provide a new direction for the research and development of antiviral drugs. These activities result from the specific binding of their heterocyclic structures to biomolecules (e.g., enzymes or receptors) that regulate physiological processes. The high efficiency of photocatalytic synthesis enables the preparation of complex isoxazole derivatives, and accelerates the discovery of new drugs. For example, the COX-2 inhibitor valdecoxib (trade name Bextra) contains an isoxazole ring for relief of arthritic pain, demonstrating the clinical value of this structure. In agriculture, the isoxazole compound is used as a novel pesticide and herbicide, and solves the difficult problems of resistant pests and weeds. The isoxazole tolfenpyrad (Vykenda ℃ C. In the first place) effectively prevents and cures mites, thrips and other difficultly-prevented pests through a contact poisoning and stomach poisoning dual mechanism, and has unique action mechanism and is not easy to cause resistance. Clomazone can inhibit HPPD enzyme in weeds to block carotenoid synthesis, so that weeds are whitened and dead, and the clomazone has remarkable effect on broadleaf weeds in corn and sugarcane fields. The green synthesis method of the pesticides reduces harmful byproducts and improves crop yield and food safety. In the material science, the polymer form of isoxazole is applied to semiconductor manufacturing, and the electrical insulation property and the thermal stability of the isoxazole make the isoxazole an ideal material for electronic devices. In addition, isoxazole derivatives are used in the fields of dyes, high temperature lubricants, etc., for example, some dyes realize vivid colors and light fastness by utilizing their structural characteristics, and lubricants rely on their stability at high temperatures. The accurate control capability of the photocatalytic synthesis enables the material performance to be customizable and meets the high-end application requirements. The photocatalytic synthesis of isoxazole is used as an efficient and green chemical method, and provides a new way for preparing the key heterocyclic compound. The method utilizes light energy to drive reaction, avoids the conditions of high temperature and high pressure in the traditional synthesis, obviously reduces energy consumption and environmental pollution, and accords with the pursuit of modern chemistry on sustainability. In a word, the photocatalytic synthesis of isoxazole not only promotes the innovation of chemical synthesis, but also expands the synthesis and application of isoxazole further along with the continuous optimization of the photocatalytic technology, thereby bringing more benefits to human society. However, there is still room for improvement in how to improve the yield of the product by designing and optimizing the raw material selection, the ratio and the reaction conditions for synthesizing isoxazoles by visible light catalysis. ‌ A Disclosure of Invention In order to overcome the defects in the prior art, the invention provides a method for synthesizing isoxazole compounds under the condition of visible light catalysis. The method comprises the steps of dissolving a compound 1 in 1, 2-dichloroethane, adding tert-butyl nitrite, bromoform, alkali and a photocatalyst, irradiating with visible light in an inert gas environment, stirring at room temperature for reaction, removing a solvent under reduced pressure after the reaction is finished, and purifying a crude product by a silica gel column to obtain the isoxazole compound. The invention develops a brand-new method for preparing the isoxazole compound by visible light catalysis, which not only avoids the conditions of high temperature and high pressure in the traditional synthesis method and obviously reduces energy consumption and environmental pollution, but also effectively improves the yield of the isoxazole compound by regulating and controlling reaction conditions and optimizing raw material sel