98-46-4Relevant articles and documents
The polyhedral nature of selenium-catalysed reactions: Se(iv) species instead of Se(vi) species make the difference in the on water selenium-mediated oxidation of arylamines
Capperucci, Antonella,Dalia, Camilla,Tanini, Damiano
supporting information, p. 5680 - 5686 (2021/08/16)
Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyl diselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads to azoxyarenes. Careful mechanistic analysis and 77Se NMR studies revealed that only Se(iv) species, such as benzeneperoxyseleninic acid, are the active oxidants involved in the catalytic cycle operating in water and leading to nitroarenes. While other selenium-catalysed oxidations occurring in organic solvents have been recently demonstrated to proceed through Se(vi) key intermediates, the on water oxidation of anilines to nitroarenes does not. These findings shed new light on the multifaceted nature of organoselenium-catalysed transformations and open new directions to exploit selenium-based catalysis.
Preparation method of m-nitrobenzotrifluoride
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Paragraph 0038-0045; 0049-0051, (2020/08/22)
The invention relates to a preparation method of m-nitrobenzotrifluoride. The method includes carrying out nitration reaction on trifluorotoluene, concentrated sulfuric acid and nitric acid in an organic solvent; specifically, stirring trifluorotoluene, an organic solvent and concentrated sulfuric acid under the condition that the temperature is controlled to be 30-40 DEG C, adding fuming nitric acid is dropwise, performing a heat preservation reaction for 6-10 h; after the reaction is completed, standing and performing liquid separation, adjusting the pH of an organic phase to be alkaline with an alkaline aqueous solution, performing desolvation on the organic phase, and finally performing reduced pressure distillation to obtain m-nitrotrifluorotoluene. According to the invention, dichloroethane, carbon tetrachloride and other chlorinated non-polar solvents are used as reaction solvents for nitration reaction, so violent heat release in the nitration reaction process is reduced, the reaction conditions are mild, and the safety is improved; meanwhile, the dosage of acid and the dosage of post-treatment alkali are greatly reduced, and three wastes are reduced, so that the post-treatment is simple, the product is easy to separate, the operation is simple and convenient, side reactions are few, the yield is high, the product purity is high and the process pollution is small.
o-aminotrifluorotoluene synthesis method
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Paragraph 0005; 0013; 0016; 0019, (2020/01/25)
The invention discloses an o-aminotrifluorotoluene synthesis method, wherein trifluorotoluene is used as a raw material, and a target compound is obtained through two-step reaction of nitration and reduction. Compared with the method in the prior art, the method of the invention has the following characteristics that trifluorotoluene is used as the raw material, so that the source is wide, and thepreparation is convenient; the nitration reaction is carried out at a normal pressure and a low temperature, so that the corrosion of the material to the pipeline and the equipment is small, and thenitration reaction is safe and reliable to the environment and operators; and the cheap nickel catalyst is used for replacing the common noble metal catalysts such as palladium, platinum and the like,so that the production cost is reduced, the methanol as the solvent is convenient to recover and can be recycled, and the emission of organic matters in the production process is reduced.
Catalytic trifluoromethylation of iodoarenes by use of 2-trifluoromethylated benzimidazoline as trifluoromethylating reagent
Akiyama, Takahiko,Ishikawa, Taisuke,Kamiyama, Nanami,Uchikura, Tatsuhiro
supporting information, p. 2442 - 2447 (2020/11/07)
The trifluoromethylation of iodoarenes was accomplished by use of a 2-trifluoromethylbenzimidazoline derivative as the trifluoromethylating reagent and a catalytic amount of Cu(I) in the presence of 2,2'-bipyridyl as the ligand. Through a mechanistic study, we found that the oxidative addition of the iodoarene to the Cu(I)–CF3 species is the rate-determining step.
Base promoted peroxide systems for the efficient synthesis of nitroarenes and benzamides
Gupta, Sampa,Ansari, Alisha,Sashidhara, Koneni V.
supporting information, (2019/09/07)
A useful and efficient approach for the synthesis of nitroarenes from several aromatic amines (including heterocycles) using peroxide and base has been developed. This oxidative reaction is very easy to handle and afforded the products in good yields. Formation of benzamides from benzylamine was also successfully carried out with this metal-free catalytic system in good to excellent yields.
Ligand-free trifluoromethylation of iodoarenes by use of 2-Aryl-2-trifluoromethylbenzimidazoline as new trifluoromethylating reagent
Miyagawa, Masamichi,Ishikawa, Taisuke,Shinkai, Kota,Akiyama, Takahiko
supporting information, p. 29 - 31 (2019/01/04)
N-Methyl 2-aryl-2-trifluoromethylbenzimidazolines were synthesized and utilized in the trifluoromethylation reaction of iodoarenes in the presence of copper(I) salt and base. Iodoarenes bearing electron-donating and electron-withdrawing groups were tolerant to this reaction in the absence of a ligand and gave trifluorotoluene derivatives in good to high yields.
Method for processing fluoride ions in aminobenzotrifluoride
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Paragraph 0016, (2017/06/02)
The invention discloses a method for processing fluoride ions in aminobenzotrifluoride. The method for processing the fluoride ions in the aminobenzotrifluoride comprises the following steps: taking trifluorotoluene as a raw material, and carrying out mixed acid nitration and catalyzed hydrogeneration reduction under normal pressure to synthesize the aminobenzotrifluoride, wherein a coarse product contains the fluoride ions; mixing and stirring the coarse product of the aminobenzotrifluoride and refined lime proportionally, combining the fluoride ions with calcium ions of calcium oxide to generate calcium fluoride CaF2, and filtering to remove precipitate to obtain trifluoromethylbenzene; drying the trifluoromethylbenzene without the fluoride ions to obtain the refined trifluoromethylbenzene, wherein the main ingredient in the refined lime is calcium oxide CaO. By the mode, the fluoride ions in the trifluoromethylbenzene can be removed effectively, after the fluoride ions are treated once, the content of the fluoride ions can be below 10 ppm generally, and after the fluoride ions are treated twice, the content of the fluoride ions can be below 5 ppm.
Preparation method of 3-hydroxyphenyl trifluoromethyl ether
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Paragraph 0081; 0086; 0087; 0095; 0101; 0102; 0113; 0114, (2017/09/05)
The invention provides a preparation method of 3-hydroxyphenyl trifluoromethyl ether. The preparation method comprises the following steps: taking 4-trifluoromethoxyaniline as a raw material; and successively carrying out acetylation, nitrification, deacetylation, deaminizating, reduction and hydrolysis reaction on the 4-trifluoromethoxyaniline to obtain the 3-hydroxyphenyl trifluoromethyl ether. The preparation method is high in yield of products, simple to operate and low in production cost; and industrialization is facilitated.
