Regioselective synthesis of 2- and 5-trifluoromethyl-or 2- and 5-difluoromethylpyrazolo[1,5-c]pyrimidines based on 7,7,7-trifluoro-or 7,7-difluoro-2,4,6-trioxoheptanoic and 6-trifluoromethyl-or 6-difluoromethylcomanic acids
Reactions of 2-Mono- and 2,6-Disubstituted 4-Pyrones with Phenylhydrazine as General Method for the Synthesis of 3-(N-Phenylpyrazolyl)Indoles
作者:D. L. Obydennov、B. I. Usachev、V. Ya. Sosnovskikh
DOI:10.1007/s10593-014-1603-3
日期:2015.1
in protic and aprotic solvents, leading to phenylhydrazones of 3-(3-R-1-phenylpyrazol-5-yl)- or 3-(5-R-1-phenylpyrazol-3-yl)pyruvic acids (or esters), respectively. 6-Di(tri)fluoromethylcomanic acids (or esters) reacted analogously, forming the corresponding phenylhydrazones with RF group in the side chain. The obtained phenylhydrazones underwent Fischer reaction under acidic conditions, forming the
Regioselective synthesis of trifluoromethylated 3-(pyrazolyl)indoles on the basis of 6-(trifluoromethyl)comanic acid
作者:Boris I. Usachev、Dmitrii L. Obydennov、Vyacheslav Ya. Sosnovskikh
DOI:10.1016/j.jfluchem.2011.12.008
日期:2012.3
A number of trifluoromethylated 3-(pyrazolyl)indoles was synthesized from 2-(trifluoromethyl)comanic acid, its ethyl ester and amide via intermediate isomeric 5(3)-[3,3,3-trifluoro-2-(phenylhydrazono)propyl]pyrazole-3(5)-carboxylic acids and their derivatives.
Reactions of 6-(tri- and 6-(difluoromethyl))comanic acids and their ethyl esters with aniline and its 2-substituted derivatives
作者:Dmitrii L. Obydennov、Boris I. Usachev
DOI:10.1016/j.jfluchem.2012.06.003
日期:2012.9
Reactions of 6-(tri- and 6-(difluoromethyl))comanic acids with aniline, o-phenylenediamine and o-aminophenol were investigated. RF-containing derivatives of 4-pyridones, benzodiazepines and quinoxalinones were synthesized. Electrophilic properties of 6-(trifluoromethyl)comanic acid were evaluated.
Regioselective solvent-sensitive reactions of 6-(trifluoromethyl)comanic acid and its derivatives with phenylhydrazine
作者:Boris I. Usachev、Dmitrii L. Obydennov、Mikhail I. Kodess、Vyacheslav Ya. Sosnovskikh
DOI:10.1016/j.tetlet.2009.05.056
日期:2009.8
reacts regioselectively with phenylhydrazine in water to give 5-[3,3,3-trifluoro-2-(phenylhydrazono)propyl]-1-phenyl-1H-pyrazole-3-carboxylic acid. Similar reaction in dioxane leads to 3-[3,3,3-trifluoro-2-(phenylhydrazono)propyl]-1-phenyl-1H-pyrazole-5-carboxylic acid. A strong solvent influence on the reaction route was also found for 6-(trifluoromethyl)comanic acid derivatives.
Trifluoroacetylation of ethyl 2,4-dioxopentanoate. The first synthesis of 4-oxo-6-(trifluoromethyl)-4H-pyran-2-carboxylic acid and its derivatives
作者:B. I. Usachev、I. A. Bizenkov、V. Ya. Sosnovskikh
DOI:10.1007/s11172-007-0092-2
日期:2007.3
Condensation of ethyl 2,4-dioxopentanoate with ethyl trifluoroacetate in the presence of NaOEt leads to ethyl 4-oxo-6-(trifluoromethyl)-4H-pyran-2-carboxylate, from which the corresponding acid and its amide, as well as 4-hydroxy-6-(trifluoromethyl)pyridine-2-carboxamide were obtained.