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CN-122010876-A - 2-Methyl-5-trifluoromethyl furan and preparation method thereof

CN122010876ACN 122010876 ACN122010876 ACN 122010876ACN-122010876-A

Abstract

The invention belongs to the technical field of preparation of organic chemicals, and particularly relates to 2-methyl-5-trifluoromethyl furan and a preparation method thereof. Adding a solvent into trifluoroacetone, adding alkali under ice bath condition, adding 1-chloro-2-methyl epoxy ethane, reacting at room temperature, adding acid, reacting at 40-60 ℃ to complete dehydration reaction, then adding alkali for aromatization, continuously completing aromatization reaction, adding water to extract a reaction system, taking an organic phase, and rectifying to obtain 2-methyl-5-trifluoromethyl furan. The 2-methyl-5-trifluoromethyl furan and the preparation method thereof provided by the invention have the advantages of mild reaction conditions and simple steps, and the prepared 2-methyl-5-trifluoromethyl furan has high yield and is suitable for industrial production.

Inventors

  • ZHAI WEIMIN
  • YU HONGTAO
  • XIA KAI

Assignees

  • 淄博飞源化工有限公司

Dates

Publication Date
20260512
Application Date
20260414

Claims (10)

  1. 1. The preparation method of the 2-methyl-5-trifluoromethyl furan is characterized by comprising the following steps of: (1) Adding a solvent into trifluoroacetone, and adding alkali under ice bath conditions; (2) Adding 1-chloro-2-methyl ethylene oxide into the reaction system in the step (1), and reacting at room temperature; (3) Adding an acid solution into the reaction system in the step (2), reacting at 40-60 ℃, then adding alkali, and continuing the reaction to obtain a reaction solution; (4) Extracting the reaction liquid, taking an organic phase, and rectifying to obtain the 2-methyl-5-trifluoromethyl furan.
  2. 2. The method for preparing 2-methyl-5-trifluoromethyl furan according to claim 1, wherein said trifluoroacetone is a byproduct produced by hexafluoroisopropanol in the production process, the purity is more than 99%, and the purity of said 1-chloro-2-methyl ethylene oxide is more than 99%.
  3. 3. The method for preparing 2-methyl-5-trifluoromethyl furan according to claim 1, wherein the solvent in the step (1) is one of toluene, chlorobenzene, paraxylene, metaxylene and orthoxylene.
  4. 4. The method for preparing 2-methyl-5-trifluoromethyl furan according to claim 3, wherein the alkali in the step (1) is one of sodium hydroxide, potassium tert-butoxide and sodium tert-butoxide, and the molar ratio of the alkali to trifluoroacetone is 1.0-1.2:1.
  5. 5. The preparation method of 2-methyl-5-trifluoromethyl furan according to claim 1, wherein the alkali in the step (3) is one of pyridine, triethylamine, sodium carbonate and potassium carbonate, and the pH is adjusted to 8-9 by adding alkali.
  6. 6. The preparation method of 2-methyl-5-trifluoromethyl furan according to claim 5, wherein the acid in the step (3) is one of hydrochloric acid, sulfuric acid and methanesulfonic acid, and the molar ratio of trifluoroacetone to pure acid is 1:1.2-1.35.
  7. 7. The method for preparing 2-methyl-5-trifluoromethyl furan according to claim 1, wherein the mass concentration of the acid solution in the step (3) is 10-20%.
  8. 8. The method for producing 2-methyl-5-trifluoromethylfuran according to claim 1, wherein 1-chloro-2-methylethylene oxide in step (2) is first dissolved in the solvent type of step (1) and then added dropwise at 25 to 40 ℃.
  9. 9. The method for preparing 2-methyl-5-trifluoromethyl furan according to claim 1, wherein water is used as an extractant in the step (4), and an organic phase is taken after phase separation and dried.
  10. 10. A process for producing 2-methyl-5-trifluoromethylfuran according to any one of claims 1 to 9, wherein the 2-methyl-5-trifluoromethylfuran has a purity of not less than 99.8% and a yield of not less than 85%.

Description

2-Methyl-5-trifluoromethyl furan and preparation method thereof Technical Field The invention belongs to the technical field of preparation of organic chemicals, and particularly relates to 2-methyl-5-trifluoromethyl furan and a preparation method thereof. Background 2-Methyl-5-trifluoromethylfuranIs an important fluorine-containing five-membered heterocyclic compound, and the molecular formula of the fluorine-containing five-membered heterocyclic compound is C 6H5F3 O. The compound takes a furan ring as a core skeleton, simultaneously connects two key functional groups of methyl and trifluoromethyl, and has important application value in the fields of medical intermediates, fine chemicals, functional materials, agrochemicals and the like. Furan rings are basic structural units of various bioactive molecules and functional materials, and the introduction of trifluoromethyl can obviously improve the fat solubility, metabolic stability and acid-base solubility of the compound, and simultaneously regulate the electronic effect and steric hindrance of molecules, so that 2-methyl-5-trifluoromethyl furan is often used as a core structural fragment for constructing drug molecules with therapeutic potential, efficient agricultural chemicals and novel organic functional materials. In addition, the compound has abundant reactive sites, can be further derivatized to prepare various downstream products with high added values, and has wide application prospects in organic synthesis and industrial production. At present, a direct preparation method for 2-methyl-5-trifluoromethyl furan is not disclosed in the prior art, and the disclosed related processes are all for preparing derivatives or structural analogues thereof, so that a target product cannot be obtained efficiently. Patent CN115353499A discloses a synthesis method of 2-halomethyl-5-trifluoromethyl furan, and patent CN119977918A discloses a process for preparing 2-bromomethyl-5-trifluoromethyl furan by using acetoacetate and halogenated trifluoroacetone as raw materials under the action of alkaline substances and catalysts. Both introduce halogen atoms at methyl sites, and are not used for directly preparing 2-methyl-5-trifluoromethyl furan, if a target product is obtained, multi-step reactions such as dehalogenation reduction and the like are required to be additionally carried out, so that the method has the problems of complicated steps, low total yield, high separation and purification difficulty, high production cost and the like, and is difficult to realize industrial production. Patent CN110272400a discloses a synthesis method of 2-trifluoromethyl substituted furan compound and its derivative, the process constructs furan ring through serial cyclization reaction of propargyl alcohol and trifluoroacetyl compound, but the prepared product structure has obvious difference with 2-methyl-5-trifluoromethyl furan, the target compound can not be directly obtained, and the defects of limited substrate range, uneasy control of reaction selectivity and the like exist, which is not suitable for large-scale preparation of 2-methyl-5-trifluoromethyl furan. Therefore, the prior art lacks a high-efficiency, mild and industrialized direct preparation method of 2-methyl-5-trifluoromethyl furan, and the reported preparation process of the derivative has the defects of long steps, low yield, high cost and the like. Disclosure of Invention The invention aims to overcome the defects in the prior art, and provides the 2-methyl-5-trifluoromethyl furan and the preparation method thereof, wherein the reaction conditions are mild, the steps are concise, and the prepared 2-methyl-5-trifluoromethyl furan has high yield and is suitable for industrial production. The preparation method of the 2-methyl-5-trifluoromethyl furan comprises the following steps: (1) Adding a solvent into trifluoroacetone, and adding alkali under ice bath conditions to complete deprotonation reaction; (2) Adding 1-chloro-2-methyl ethylene oxide into the reaction system in the step (1), and reacting at room temperature; (3) Adding an acid solution into the reaction system in the step (2), reacting at 40-60 ℃, then adding alkali, and continuously completing the reaction; (4) And (3) post-treatment, namely extracting the reaction system, taking an organic phase, and rectifying to obtain the 2-methyl-5-trifluoromethyl furan. The trifluoroacetone is a byproduct generated by hexafluoroisopropanol in the production process, the purity is more than 99%, and the purity of the 1-chloro-2-methyl ethylene oxide is more than 99%. The solvent in the step (1) is one of toluene, chlorobenzene, paraxylene, metaxylene and orthoxylene. The alkali in the step (1) is one of sodium hydroxide, potassium tert-butoxide and sodium tert-butoxide, and the molar ratio of the alkali to the trifluoroacetone is 1.0-1.2:1. And (3) adding alkali to adjust the pH to 8-9, wherein the alkali in the step (3) is one of pyridine, triethylamine, sodi