652-34-6Relevant articles and documents
Preparation method 2, 3, 5, 6 - tetrafluoro-phenol
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Paragraph 0020; 0026-0029, (2020/08/09)
The invention discloses a method for preparing 2,3,5,6-tetrafluorophenol. The method comprises the following steps: enabling 2,3,4,5,6-pentafluorobenzoic acid as a raw material to react with inorganicalkali and a phase transfer catalyst in water so as to obtain 4-hydroxy-2,3,5,6-tetrafluorophenol, and performing decarboxylation, thereby obtaining 2,3,5,6-tetrafluorophenol. By adopting the 2,3,4,5,6-pentafluorobenzoic acid as the raw material, the cost of the raw material can be greatly reduced, no special or harsh reaction condition is needed, production equipment is not highly required, nospecial waste is generated, the intermittent is easy to separate, the preparation cost and the labor cost of production can be reduced, and the economic benefits can be increased.
High throughput 'catch-and-release' synthesis within spatially discrete gel arrays
Boehner, Christine M.,Marsden, David M.,Sore, Hannah F.,Norton, David,Spring, David R.
supporting information; experimental part, p. 5930 - 5932 (2010/11/21)
A tetrafluorophenol acrylamide monomer unit was synthesised, co-polymerised and grafted onto a glass slide to form individual gel spots. As a proof of principle study, a small library of amides was rapidly synthesised within these gel spots using 'catch-and-release' chemistry, including the biologically interesting quorum sensing acyl-homoserine lactones. The tetrafluorophenol acrylamide gel provides an efficient platform to synthesise and screen small molecules for biological activity.
Fragmentation of radical anions of polyfluorinated benzoates
Konovalov, Valery V.,Laev, Sergey S.,Beregovaya, Irina V.,Shchegoleva, Lyudmila N.,Shteingarts, Vitalij D.,Tsvetkov, Yuri D.,Bilkis, Itzhak
, p. 352 - 361 (2007/10/03)
A comprehensive study of the symmetry forbidden fragmentation of short-lived radical anions (RAs) has been undertaken for the complete set of polyfluorinated benzoates (C6FnH5-nCO22, n = 1-5). The decay rate constants (kc) of RAs have been determined in aqueous alkaline solution (pH 13.4) by electron photoinjection (EPI) from mercury electrodes and were found to increase dramatically from ≤3 × 103 s-1 (3-F - C6H4CO2-) to (1.2 ± 0.8) × 109 s-1 (C6F5CO2-). The regioselectivity of C-F bond cleavage in the RA fragmentation has been revealed by structure assignment of reduction products of the polyfluorinated benzoic acids by Na, K, and Zn in liquid NH3, as well as by Zn in aqueous NH3 and aqueous alkaline solutions. The kc values depend on the position of the cleaved fluorine to the CO2- group generally in the order para > ortho > meta, and to sharply increase if adjacent fluorine atoms are present. The observed trends reveal that the kinetics of the RA fragmentation reaction is not controlled by the reaction thermodynamics. Semiempirical UHF/INDO calculations, the validity of which has been confirmed by ab initio ROHF/6-31+G calculations, were done to rationalize the observed trends. The reaction transition state (TS) was considered to arise from the RA's and 2*states crossing avoided due to out-of-plane deviation of the cleaving C-F bond. The satisfactory linear correlation (R = 0.96) between the model reaction energy barrier Ea and log kc has been achieved with modeling the local solvation of the CO2- group by its protonation.
