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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Síntese de 2-[3h-pirazol-2-il]trifluormetilpirimidinas Alquil, aril e heteroaril substituidas / Synthesis of 2-[3h-pyrazol-2-yl]trifluoromethylpyrimidines alkyl, aryl and heteroaril substituted

Martins, Demétrius Bernardes 14 July 2004 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work describes a general methodology for the synthesis of a novel series of 4-alkyl, 4-aryl, heteroaryl-2-[5-methyl-4-(2-hidroxyethyl)-3-oxo-1,2-dihydro-3H-pyrazol-2-yl]-6(4)-trifluoromethylpyrimidines. The precursors β-alkoxyvinyl trihalomethyl ketones of the general formula, F3C-C(O)-C(R2)=C(R)OR1, where R= H, CH3, i-Pr, Ph, 4-OCH3Ph, 2-C4H3O, 2-C4H3S, R1= CH3, C2H5 and R2 = H, CH3, R-R2= -(CH2)3-, were obtained from trifluoroacetylation reactions of enoleters and acetals derived from alkyl, cicloalkyl, methyl Ketones and 4-substituted acetophenones, propiophenones. And the precursor amidínico synthesized from 2-acetyl-butyrolactone with aminoguanidine bicarbonate in the presence of acetate of ammonium. The compounds objective of this study was obtained from the reaction of cyclocondensation reaction of 4-alkoxy-1,1,1-trifluoro-3-alken-2-ones with 1-amidino-4-(2-hydroxyethyl)-3-methyl-3-pyrazolin-5-one in the presence of anhydrous potassium carbonate. With yield of 35-80%. All the compounds 3H-pyzolil-pyrimidine were identified by 1H, 13C and 19F NMR spectra, IR, CG-MS and the purity of the compounds confirmed for it analyzes elemental. / Este trabalho descreve uma metodologia geral para síntese de uma série de novas 4-alquil-, 4-aril-, 4-heteroaril-2[5-metil-4-(2-hidroxietil)3-oxo-1,2-diidro-3H-pirazol-2-il]-6(4)-trifluormetilpirimidinas. Os precursores β-alcoxivinil trifluorometil cetonas de formula geral F3C-C(O)-C(R2)=C(R)OR1, onde R= H, CH3, i-Pr, Ph, 4-OCH3Ph, 2-C4H3O, 2-C4H3S, R1= CH3, C2H5 e R2 = H, CH3, R-R2= -(CH2)3- foram obtidas a partir de reações de trifluoracetilação de enoléteres e acetais derivados de alquil, cilcloalquil (heteroaril) metil cetonas, acetofenonas e propiofenonas 4-substituidas. E o precursor amidínico sintetizado a partir de 2-acetil-butirolactona reagindo com aminoguanidina bicarbonato na presença de acetato de amônio. Os compostos alvo deste estudo foram obtidos a partir da reação de ciclocondensação de 4-metoxi-4-alquil(aril)(heteroaril)-1,1,1-trifluor-3-alquen-2-onas frente a 5-metil-4-(2-hidroxietil)-3-oxo-1,2-diihidro-3H-2-amidinopirazol na presença de carbonato de potássio anidro, com rendimentos que variaram de 35 80%. Todos os compostos 3H-pizolil-pirimidina foram identificados por técnicas espectroscopicas de RMN (1H, 13C, 19F), IR, e CG-MS e a pureza dos compostos confirmada por analise elementar .
32

Estudos conformacionais pela espectroscopia no infravermelho e calculos teoricos de alguns compostos heterociclicos 2-substituidos / Infrared and theoretical investigation of conformational isomerism in some 2-substituted heterocyclic compounds

Mesquita, Alexandre Pinto 24 February 2005 (has links)
Orientador: Roberto Rittner / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-04T14:36:06Z (GMT). No. of bitstreams: 1 Mesquita_AlexandrePinto_M.pdf: 3953195 bytes, checksum: 418e539bcacd86a111fd5ab90fb668d9 (MD5) Previous issue date: 2005 / Mestrado / Quimica Organica / Mestre em Química
33

Síntese e atividades antimicrobiana/antioxidante de 1-(pirazolin-1-il)-2-[(aril/heteroaril)metileno] carboidrazidas trifluormetil substituídas / Synthesis and antioxidant/antimicrobial activities of 1-(pyrazolin-1yl)-2-[aryl(heteroaryl)methylene] carbohydrazides trifluoromethyl substituted

Cavinatto, Susiane 16 September 2010 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work initially describes the regioselective synthesis of a series of 3-alkyl(aryl/heteroaryl)-5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazole-1-carbohydrazides (2) from the monocyclocondensation reaction of 4-alkyl(aryl/heteroaryl)-1,1,1-trifluoro-4-methoxy-3-alken-2-ones (1), where alkyl= Me, aryl= Ph, 4-MePh, 1-Naphthyl, heteroaryl= Fur-2-yl, Thien-2-yl, with carbohydrazide. The resulting pyrazolyl carbohydrazides (2) were obtained in good yields (62 92 %) when the reactions were performed in ethanol as solvent at 25 ° C in reaction times of 18 20 hours in the molar ratio of 1:1. In subsequent reaction step, a novel series of semicarbazones (3) derived from initial pyrazolyl carbohydrazides (2) was obtained from the condensation reaction of 3-alkyl(aryl/heteroaryl)-5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazole-1-carbohydrazides (2) with aryl/ heteroaryl substituted aldehydes or acetophenone. The semicarbazones (3) were isolated in yields of 52 97 % when the reaction was conducted in ethanol solvent, at temperature of 60 ° C, in reaction time of 7 hours. Secondly, aiming the synthesis of non symmetrical bis-pyrazoles systems, were performed reactions involving 5-trifluoromethyl-3-phenyl-5-hydroxy-4,5-dihydro-1H-pyrazole-1-carbohydrazide (2b) and 2,4-pentanedione. These reactions led to the isolation of ethyl 5-trifluoromethyl-3-phenyl-5-hydroxy-4,5-dihydro-1H-pyrazole-1-carboxylate (6b) and 3,5-dimethyl-1H-pyrazole (7) simultaneously, ando not to the bis-pyrazole system theoretically predicted. Finally, we have tested a cleavage reaction of the carbonyl compound 1,1 -carbonyl-bis-[3-(4-tolyl)-5-trifluoromethyl-1H-pyrazole] (8c), which was, obtained by the bicyclization reaction of 1,1,1-trifluoro-4-(4-tolyl)-4-methoxy-3-buten-2-one (1c) with 1,3-diaminoguanidine hydrochloride. So, the reaction of 8c with phenylhydrazine and hydroxylamine hydrochloride led to the synthesis of 3-(4-tolyl)-5-(trifluoromethyl)-1H-1-phenyl pyrazole and 5-hydroxy-3-(4-tolyl)-5-(trifluoromethyl)-4,5-dihydroisoxazole, respectively. In addition, the series of 3-alkyl(aryl/heteroaryl)-5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazole-1-carbohydrazides (2) and the novel semicarbazones (3) were evaluated for antimicrobial activity and antioxidant potential. As the result, only concentrations greater or equal than 125 μg/mL inhibited the growth of tested bacteria and fungi and, through the test of antioxidant activity, by the DPPH method, qualitatively and quantitatively, it was observed that all substances provided activity as trappers of the stable free radical DPPH. The compounds were characterized by 1H and 13C {1H} NMR Spectroscopy, Gas Chromatography coupled to Mass Spectrometry (GC-MS), Infrared Spectroscopy (IR), X-Ray Diffraction and their purity determined by CHN Elemental Analysis. / A presente dissertação descreve inicialmente a síntese regiosseletiva de uma série de 3-alquil(aril/heteroaril)-5-trifluormetil-5-hidróxi-4,5-diidro-1H-pirazolil-1-carboidrazidas (2) a partir da reação de monociclocondensação de 4-alquil(aril/heteroaril)-1,1,1-triflúor-4-metóxi-3-alquen-2-onas (1), onde alquil = Me, aril= Ph, 4-MePh, 1-naftil, heteroaril= 2-furil, 2-tienil com carboidrazida. As pirazolil carboidrazidas resultantes (2) foram obtidas em bons rendimentos (62 92 %) quando as reações foram executadas em etanol como solvente, à temperatura de 25 ºC, em tempos reacionais de 18 a 20 horas, na proporção molar de 1:1 entre os reagentes. Em passo reacional subsequente, uma nova série de semicarbazonas (3) derivadas das pirazolil carboidrazidas iniciais (2) foi obtida a partir de reações de condensação de 3-alquil(aril/heteroaril)-5-trifluormetil-5-hidróxi-4,5-diidro-1H-pirazolil-1-carboidrazidas (2) com aldeídos arilícos, heteroarílicos e acetofenona. As semicarbazonas (3) foram isoladas em rendimentos de 52 97 % quando se realizou as reações em meio etanol, à temperatura de 60 °C, em tempo reacional de 7 horas. Finalmente, testou-se reações de clivagem do composto carbonil-1,1 -bis-3-(4-toluil)-5-trifluormetil-1H-pirazol (8c), obtido a partir da reação de biciclização entre 1,1,1-triflúor-4-(4-toluil)-4-metóxi-3-buten-2-ona (1c) e, posteriormente com cloridrato de 1,3 diaminoguanidina. Assim, reação de 8c com fenilhidrazina e cloridrato de hidroxilamina levaram à síntese de 5-trifluormetil-3-(4-toluil)-1H-1-fenilpirazol e 5-trifluormetil-5-hidróxi-3-(4-toluil)-4,5-diidroxi-isoxazol, respectivamente. Complementarmente, as séries das 3-alquil(aril/heteroaril)-5-trifluormetil-5-hidróxi-4,5-diidro-1H-pirazolil-1-carboidrazidas (2) e das novas semicarbazonas (3) foram avaliadas quanto à atividade antimicrobiana e o potencial antioxidante. Como resultado, somente as concentrações maiores ou iguais a 125 μg/mL inibiram o crescimento das bactérias e fungos testados e através do teste de atividade antioxidante, pelo método DPPH qualitativo e quantitativo, observou-se que todas as substâncias apresentaram atividade como trapeadores do radical livre estável DPPH. Os compostos foram caracterizados por Espectroscopia de RMN de 1H e 13C {1H}, Cromatografia Gasosa acoplada à Espectrometria de Massas (CG-MS), Espectroscopia de Infravermelho (IV), Difração de Raios-X e sua pureza determinada via Análise Elementar CHN. Secundariamente, visando à síntese de sistemas bis-pirazólicos não simétricos realizaram-se reações envolvendo a 3-fenil-5-trifluormetil-5-hidróxi-4,5-diidro-1H-pirazolil-1-carboidrazida (2b) e a 2,4-pentanodiona. Estas reações conduziram ao isolamento de 3-fenil-5-trifluormetil-5-hidróxi-4,5-diidro-1H-pirazolil-1-carboxilato de etila (6b) e de 3,5-dimetil-1H-pirazol (7) simultaneamente, e não, do sistema bis-pirazólico teoricamente previsto.
34

Síntese de 1-[aril(heteroaril)]-5-(3,3,3-trifluor-2-oxopropilideno) pirrolidin-2-onas / Synthesis of 1-[aryl(heteroaryl)]-5-(3,3,3-trifluoro-2-oxo-propylidene)pyrrolidin-2-ones

Oliveira, Graciela Aparecida de 31 October 2005 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The synthesis of a series of ten 1-[aryl(heteroaryl)]-5-(3,3,3-trifluoro-2-oxopropilideno) pyrrolidin-2-ones by intramolecular cyclocondensation reaction of methyl 7,7,7-trifluoro-4-[aryl(heteroaryl)amino]-6-oxo-4-heptanoates in excellent yields (69-95%) is reported. The methyl heptanoate intermediates were obtained in three sequential steps: (i) acetalization of 4-oxopentanoic acid with trimethyl orthoformate; (ii) acetylation of the acetal with trifluoroacetic anhydride; (iii) reaction of methyl 7,7,7-trifluoro-4-methoxy-6-oxo-4-heptanoate with primary amines [R NH2, where R = PhCH2, PhCH2CH2, Ph, 4-Me-C6H4, 4-MeO-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-NH2-C6H4, pyrid-2-yl, isoxazol-2-yl) to obtain methyl 7,7,7-trifluoro-4-[aryl(heteroaryl)amino]-6-oxo-4-heptanoates in moderate to good yields (57 95%). / Este trabalho descreve a síntese de uma série de 1-[aril(heteroaril)]-5-(3,3,3-trifluor-2-oxo-propilideno)pirrolidin-2-onas a partir da reação de ciclização intramolecular de 7,7,7-trifluor-4[aril(heteroaril)amino]-6-oxo-4-heptenoatos de metila. Estes compostos foram obtidos em três etapas: i) acetalização do ácido 4-oxopentanóico com trimetilortoformiato em presença de ácido p-toluenossulfônico; ii) a seguir o acetal foi acilado com cloreto de tricloro acetila ou anidrido trifluoracético para obtenção de 7,7,7-tricloro-4-metoxi-6-oxo-4-heptenoato de metila e 7,7,7-trifluor-4-metoxi-6-oxo-4-heptenoato de metila, respectivamente; iii) a reação de 7,7,7-trifluor-4-metoxi-6-oxo-4-heptenoato de metila com aminas primárias (RNH2, onde R = benzil, fenetil, fenil, 4-CH3C6H4, 4-CH3OC6H4, 4-ClC6H4, 4-BrC6H4, 4-NH2C6H4, pirid-2-il, isoxazol-3-il) levou a obtenção dos 7,7,7-trifluor-4[aril(heteroaril)amino]-6-oxo-4-heptenoatos de metila com rendimentos de 57 a 95%.

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