- Studies in fluorinated 1,3-diketones and related compounds. Part XVII. Synthesis and spectroscopic studies of some new 5-alkyl-3-fluoroaryl-1-pentafluoroaryl-pyrazoles and 2-amino-6-alkyl(perfluoroalkyl)-4-aryl pyrimidines
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Six new 3-(4'-fluorophenyl)-1,5-trisubstituted pyrazoles have been synthesized from the appropriate fluorinated 1,3-diketones and pentafluorophenylhydrazine in the presence of absolute ethanol and hydrochloric acid, viz., 1-pentafluorophenyl-3-(4'-fluorophenyl)-5-methylpyrazole, 1-pentafluorophenyl-3-(4'-fluorophenyl-5-trifluoromethylpyrazole, 5-ethyl-1-pentafluorophenyl-3-(4'-fluorophenyl) pyrazole, 5-(pentafluoroethyl)-1-pentafluorophenyl-3-(4'-fluorophenyl) pyrazole, 1-pentafluorophenyl-3-(4'-fluorophenyl 5-n-propylpyrazole and 5-(heptafluoropropyl)-1-pentafluorophenyl-3-(4'-fluorophenyl) pyrazole.In addition, six new 2-amino-4-(4'-fluorophenyl)-6-alkyl(perfluoroalkyl)-trisubstituted pyrimidines have been prepared from the same diketones and guanidine carbonate in the presence of hydrochloric acid using absolute ethanol as a solvent, viz., 2-amino-4-(4'-fluorophenyl)-6-methylpyrimidine., 2-amino-4-(4'-fluorophenyl)-6-trifluoromethylpyrimidine, 2-amino-6-ethyl-4-(4'-fluorophenyl)pyrimidine, 2-amino-6-pentafluoroethyl-4-(4'-fluorophenyl)pyrimidine, 2-amino-4-(4'-fluorophenyl)-6-n-propylpyrimidine and 2-amino-6-(heptafluoropropyl)-4-(4'-fluorophenyl)pyrimidine.All new fluorinated pyrazoles as well as pyrimidines have been characterized by elemental analyses as well as spectral studies.
- Sareen, Vineeta,Jain, Sunita
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- Synthesis of polyfluorinated arylhydrazines, arylhydrazones and 3-methyl-1-aryl-1H-indazoles
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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.
- Politanskaya, Larisa,Bagryanskaya, Irina,Tretyakov, Evgeny
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- Facile Synthesis of Fluorine containing 1,3,5-triarylpyrazoles and 3,5-Diarylisoxazoles
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Fluorine containing 1,3-diarylchalchones on condensation with pentafluorophenylhydrazine in absolute ethanol, afforded the corresponding 1,3,5-triarylpyrazoles and with hydroxyl amine hydrochloride in pyridine yielded 3,5-diarylisoxazoles.Fluorinated chalchones were synthesised by condensation of the appropriate acetophenones and aromatic aldehydes in aqueous ethanolic sodium hydroxide solution.All the compounds were characterised by their analytical and ir, 1H nmr, 19F nmr and mass spectral data.Mass fragmentation patterns of these compounds have also been discussed.
- Joshi, Krishna C.,Pathak, Vijai N.,Gupta, Ragini
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p. 773 - 777
(2007/10/02)
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- Studies in spiro heterocycles. Part 4(1): Investigation of the reactions of fluorinated 3-aroylmethylene-indol-2-ones with hydrazine and phenylhydrazine and synthesis of spiro [indole-3,3'-pyrazol]-2-ones.
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Reactions of various 3-aroylmethylene-indol-2-ones with hydrazine and phenylhydrazine under exactly similar conditions have been carried out. The reaction with phenylhydrazine has not been investigated earlier. It was found that although the reaction with hydrazine hydrate afforded a spiro derivative viz., spiro[3H-indole-3,3'-(3H)pyrazol]-2(1H)-one, that with phenylhydrazine yielded simply a hydrazone derivative. Representative spiro compounds have been screened for antifertility activity but none was found active at a dose of 10 mg/kg in adult female rats.
- Joshi,Jain,Garg
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- SYNTHESIS OF SOME NEW FLUORINE CONTAINING 1,3,4-TRISUBSTITUTED 4,8-DIHYDRO-1H-PYRAZOLOTHIAZEPIN-7(6H)-ONES AND RELATED COMPOUNDS
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A series of new fluorine containing 1,3,4-trisubstituted 4,8-dihydro-1H-pyrazolothiazepin-7(6H)-ones have been synthesized by the condensation of fluorine containing 5-amino-1,3-disubstituted pyrazoles with an appropriate aromatic aldehyde/ketone and mercaptoacetic acid in dry toluene.The reduction of 7-oxo group and the conversion of 7-oxo to 7-thione group have been carried out for the first time in such systems by an elegant procedure.
- Joshi, Krishna C.,Dubey, Kalpana,Dandia, Anshu
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