13656-49-0Relevant articles and documents
A 2, 4 - difluoro - 3, 5 - dichloro nitrobenzene synthesis of 1, 3, 5 - trichloro - 2, 4, 6 - trifluorobenzene
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Paragraph 0052; 0053; 0054; 0055; 0056; 0057, (2017/08/25)
The invention discloses a method for synthesizing 1,3,5-trichloro-2,4,6-trifluorobenzene from 2,4-difluoro-3,5-dichloronitrobenzene. The method comprises performing chlorination reaction on 2,4-difluoro-3,5-dichloronitrobenzene in chlorine atmosphere to obtain a chloride, and controlling the chlorination reaction temperature to 160-195 DEG C; performing nitration reaction on the chloride in a mixed acid solution of sulfuric acid and nitric acid to obtain a nitro compound, and controlling the nitration reaction temperature to 60-110 DEG C; and performing fluorination reaction on the nitro compound with a fluoride under a waterless condition so as to obtain 1,3,5-trichloro-2,4,6-trifluorobenzene, and controlling the fluorination reaction temperature to 80-200 DEG C. The product synthesized by the method is high in selectivity, and the yield and the purity of products of all steps are relatively high, and operation is simple.
Thermal (iodide) and photoinduced electron-transfer catalysis in biaryl synthesis via aromatic arylations with diazonium salts
Kosynkin,Bockman,Kochi
, p. 4846 - 4855 (2007/10/03)
The dediazoniative arylation of various aromatic hydrocarbons (Ar'H) with diazonium salts (ArN2+) in acetonitrile can be readily effected to biaryls (Ar-Ar') in high yields, simply by the addition of small (catalytic) amounts of sodium iodide. [In the absence of Ar'H, the competitive iodination to ArI is nearly quantitative.] Iodide catalysis of biaryl formation is efficiently mediated by aryl radicals (Ar') that participate in an efficient homolytic chain process in which ArN2+ acts as a 1-electron oxidant. The complex kinetics of such an electron-transfer chain or ETC process (Scheme I) is quantitatively verified by computer simulation of the Ar'H-dependent (a) competition between arylation vs iodination and (b) catalytic efficiency of iodide. using the GEAR algorithms. ETC catalysis also pertains to the alternative photochemical procedure for arylation (in the absence of iodide), in which the deliberate irradiation of the charge-transfer band of the precursor complex (ArN2+, Ar'H) initiates the same homolytic chain arylation. The latter underscores the mechanistic generality of the ETC formulation for various types of catalytic dediazoniations of aromatic diazonium salts.
