L. Politanskaya, I. Bagryanskaya, E. Tretyakov
Oct 1, 2018
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Influential Citations
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Journal
Journal of Fluorine Chemistry
Abstract
Abstract Polyfluorinated arylhydrazones were synthesized starting from 1-(4-amino-tetrafluorophenyl)ethanone and polyfluorinated arylhydrazines by action of p-toluenesulfonic acid in good yields. The resulting mixtures of E- and Z-isomers were next treated with K2CO3 in MeCN at room temperature. Under these mild reaction conditions Z-isomers underwent intramolecular nucleophilic cyclization to form 3-methyl-1-aryl-1H-indazole derivatives, while E-isomers were not active and were isolated unchanged. Molecular and crystal structures of prepared polyfluorinated (E)-arylhydrazones as well as selected 3-methyl-1-aryl-1H-indazoles were solved by the X-ray diffraction analysis. Meanwhile, the polyfluorinated acetophenone reacted with hydrazine in THF in the absence of a catalyst through a condensation–nucleophilic substitution cascade process to form a 3-methyl-1H-indazole derivative in excellent yield.