954-15-4Relevant academic research and scientific papers
New preparation method of 1-bromo-methyl-2,3,5,6-tetrafluoro-4-(trifluoromethyl)benzene
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Paragraph 0034; 0036-0037; 0046-0048, (2019/08/20)
The invention discloses a new preparation method of 1-bromo-methyl-2,3,5,6-tetrafluoro-4-(trifluoromethyl)benzene. The method comprises the steps that with a compound 2,3,5,6-tetrafluoro-terephthalicacid as a raw material, through alkylation, 2,3,5,6-tetrafluoro-terephthalic acid diester is obtained firstly, then single hydrolysis is conducted, formic acid is fluorinated into trifluoromethyl so as to obtain 2,3,5,6-tetrafluoro-4-trifluoromethyl benzoate, and after the 2,3,5,6-tetrafluoro-4-trifluoromethyl benzoate is reduced into alcohol, through bromination, the target compound is obtained.According to the method, the reaction raw materials are easy to obtain and low in price, few reaction by-products are generated, and the product is easy to purify, high in yield and suitable for massindustrial production; therefore, reliable guarantee is provided for a key intermediate of a novel drug 2-hydroxyl-5-(2,3,5,6-tetrafluoro-4-trifluoromethyl benzylamino)benzoic acid.
Extending the series of p-substituted tetrafluorobenzoic acids: synthesis, properties and structure
Zaitsev, Kirill V.,Oprunenko, Yuri F.,Lermontova, Elmira Kh.,Churakov, Andrei V.
, p. 49 - 58 (2017/03/22)
The synthesis of the derivatives of p-aminotetrafluorobenzoic acid, p-H2NC6F4CO2H (2b), by hydrolysis, acylation or interaction with aldehydes was developed giving H2NC6F4CO2K (2a), C6F5C(O)N(H)C6F4CO2Et (3) and (E)-ArCH[dbnd]NC6F4CO2Et (4–11). The chemical derivatization of tetrafluoroterephthalic acid, p-HO2CC6F4CO2H (12), by hydrolysis, etherification and reduction was performed giving a number of symmetrical X(O)CC6F4C(O)X (13–15; X?=?Cl, NEt2, OMe) or unsymmetrical YC6F4CO2Me (15a–b, 16, 18–21; Y?=?CO2K, CO2H, CH2OH, C(O)Cl, C(O)C6H3(i-Pr)2, CO2CH2C6F4CO2Me, CO2C6H4Bu-t), HOCH2C6F4CO2H (17), [MeO2CC6F4]2Y (22, 23; Y?=?OCH2CH2O, N(H)C6H4N(H)) compounds. All substances were thoroughly investigated by spectroscopic methods (multinuclear NMR and IR spectroscopy, mass-spectrometry). The molecular structures of p-H2NC6F4CO2Et (2) and p-HO2CC6F4CO2Me (15b) have been determined by X-ray diffraction analysis.
