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Aplicação de enonas cíclicas como precursores para síntese de trifluoracetiltetraidropiridinas e 1H-pirazóis-3(5)-carboxilato de etila / Application of cyclic enones as precursors for the synthesis of trifluoroacetyltetrahydropyridines and ethyl 1H-pyrazoles-3(5)-carboxylateFernandes, Liana da Silva 15 July 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present work describes the synthesis of novel 1-alkyl(aryl)-2-alkoxy-5-trifluoroacetyl-1,2,3,4-tetrahydropyridines, aza-condensed tetrahydropyridines and ethyl-1H-pyrazoles-3(5)-carboxylate from the use of cyclic enones as precursors. The 1-alkyl(aryl)-2-alkoxy-5-trifluoroacetyl-1,2,3,4-tetrahydropyridines were synthesized using stoichiometric amounts of trifluoroacetyl dihydropyranes and different primary amines in 55 96% yield, under basic catalysis, whereas the aza-condensed tetrahydropyridines were synthesized using stoichiometric amounts of trifluoroacetyl dihydropyranes and different diamines, leading to the desired products in 81 96% yield. The acylation of 2,3-dihydrofuran, 3,4-dihydropyran and 2-alkoxy-3,4-dihydro-2H-pyran with ethyloxallyl chloride furnished esterified enones (4-(2-ethyl-oxoacetate)2,3-dihydrofuran, 5-(2-ethyl-oxoacetate)-3,4-dihydro-2H-pyran and 2-methoxy-5-(2-ethyl-oxoacetate)-3,4-dihydro-2H-pyran) in 47 81% yield. Finally, the cyclocondensation reaction between enones (4-(2-ethyl-oxoacetate)-2,3-dihydrofuran-2-oxoacetate, 5-(2-ethyl-oxoacetate)-3,4-dihydro-2H-pyran) with different hydrazines led to the synthesis of 1H-pyrazole-3(5)-carboxylate ethyl ester in 62 96% yield. The N1 H substituted ethyl-1H-pyrazole-3(5)-carboxylate esters were N-alkylated with alkyl , allyl , and benzyl halides leading to the desired N-substituted pyrazoles in 48 96% yield. / Este trabalho apresenta a síntese de três séries de compostos inéditos: 1-alquil(aril)-2-alcóxi-5-trifluoracetil-1,2,3,4-tetraidropiridinas, hexaidroimidazopiridinas e heterociclos análogos aza-condensados e 1H-pirazóis-3(5)-carboxilato de etila a partir da utilização de enonas cíclicas como precursores. As 1-alquil(aril)-2-alcóxi-5-trifluoracetil-1,2,3,4-tetraidropiridinas, foram obtidas com rendimentos entre 55 e 96%, utilizando-se quantidades estequiométricas dos 2-alcóxi-5-trifluoracetil-3,4-diidro-2H-piranos com diferentes aminas primárias, sob catálise básica de piridina, enquanto que, as hexaidroimidazopiridinas e heterociclos aza-condensados foram sintetizados através da reação entre os mesmos precursores, em relação estequiométrica, frente a diaminas conduzindo a formação dos produtos desejados em rendimentos de 81 e 96%. A acilação entre o 2,3-diidrofurano, 3,4-diidropirano e 2-alcóxi-3,4-diidro-2H-pirano com o cloreto de etiloxalila promoveu a obtenção das enonas esterificadas (4-(etil-2-oxoacetato)-2,3-diidrofurano, 5-(etil-2-oxoacetato)-3,4-diidro-2H-pirano e 2-metóxi-5-(etil-2-oxoacetato)-3,4-diidro-2H-pirano) com rendimentos de 47 e 81%. A reação de ciclocondensação entre as enonas (4-(etil-2-oxoacetato)-2,3-diidrofurano, 5-(etil-2-oxoacetato)-3,4-diidro-2H-pirano) com diferentes hidrazinas conduziu à síntese dos 1H-pirazóis-3(5)-carboxilato de etila com rendimentos entre 62 e 96%, sendo que os 1H-pirazóis-3(5)-carboxilato de etila que apresentam hidrogênio como substituinte na posição-1, foram submetidos à posterior reação de N-alquilação conduzindo aos produtos desejados com rendimentos entre 48 e 96%.
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5-Hidróxi-4,5-diidro-1H-1-(2-hidroxibenzoil)pirazóis: Planejamento, Síntese e Analgesia / 5-hydroxy-4,5-dihydro-1H-1-(2-hydroxybenzoyl)pyrazoles: Design, Synthesis and AnalgesiaMachado, Pablo 23 February 2007 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / An efficient method to obtain six 4-alkoxy-2-oxo-but-3-enoic acid ethyl esters [EtO2CC(O)C(R2)=C(R1)OR, where R1/R2/R = Me/H/Me (2a), Ph/H/Me (2b), 4-MeC6H4/H/Me (2c), 4-BrC6H4/H/Me (2d), 4-FC6H4/H/Me (2e), H/Me/Et (2f)] from acylation of enol ethers or acetals with ethyl oxalyl chloride is reported. The cyclocondensation reaction of these substrates and their trifluormethylated analogues (5a-f) [CF3C(O)C(R2)=C(OR)R1] with salicylic hydrazide furnished a series of ethyl 5-hydroxy-1-(2-hydroxybenzoyl)-4,5-dihydro-1H-pyrazole-5-carboxylates (6) and 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1-(2-hydroxybenzoyl)pyrazoles (7), respectively. The structure of the obtained compounds was determined by spectroscopy and confirmed by crystallographic studies. The design of these compounds explore the hypothesis that the hybridization of salicylic acid with an appropriate 4,5-dihydro-1Hpyrazole scaffold can supply novel potent analgesic agents. The oral administration of one compound of each series of pyrazoles (6a, 7a) caused significant analgesia in the writhing test in mice, which was similar to the analgesia caused by aspirin. / Este trabalho descreve um eficiente método para obter seis 4-alcóxi-2-oxo-3-butenoatos de etila [EtO2CC(O)C(R2)=C(R1)OR, onde R1/R2/R = Me/H/Me (2a), Ph/H/Me (2b), 4-MeC6H4/H/Me (2c), 4-BrC6H4/H/Me (2d), 4-FC6H4/H/Me (2e), H/Me/Et (2f)] a partir da acilação de enoléteres e acetais com cloreto de etil oxalila. A reação de ciclocondensação desses substratos e seus análogos trifluormetilados (5a-f) [CF3C(O)C(R2)=C(OR)R1] com salicil hidrazida forneceu respectivamente as séries de 5-etilcarboxilato-5-hidróxi-4,5-diidro-1H-1-(2-hidroxibenzoil)pirazóis (6) e 5-hidróxi-5-trifluormetil-4,5-diidro-1H-1-(2-hidroxibenzoil)pirazóis (7). Adicionalmente aos dados espectroscópicos, a estrutura dos compostos foi confirmada por experimentos de raios-X. O planejamento desses compostos explora a hipótese de que a hibridização molecular do ácido salicílico com um núcleo 4,5-diidro-1H-pirazol pode fornecer novos potentes agentes analgésicos. A administração oral de um exemplo de cada série de pirazóis (6a, 7a) causou um efeito analgésico significante no teste das contorções abdominais em camundongos, o qual foi similar ao efeito analgésico apresentado pela aspirina.
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β-Enaminonas, 5-hidróxi-4,5-diidropirazóis e 5-Hidróxi-4,5-diidroisoxazóis halometilsubstituídos: estudo molecular por difração de raios-x / β-Enaminones, 5-hydroxy-4,5-dihydropyrazole and 5-hydroxy-4,5-dihydroisoxazole halomethyl Substituted: molecular study by x-ray DiffractometryCampos, Patrick Teixeira 08 August 2008 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The molecular study by X-ray diffraction of β-aminovinyl ketones
[R3C(O)CH=C(R1)N(R4R5), onde R3 = CF3, CCl3, CHCl2; R1 = H, Me; R4 = H; R5 =
benzyl, Ph, 5-methylisoxazol-3-yl; R4, R5 = -(CH2)4-, -(CH2)2O(CH2)2-], methyl 5-
hydroxy-5-trihalomethyl-4,5-dihydro-1H-pyrazole-1-carboxylate [3-(R1), 4-(R2), and 5-
(R3) substituted, where R1 = H, Me; R2 = H, Me; R3 = CCl3, CF3], 1-cyanoacetyl-5-
trifluorometyl-5-hydroxy-4,5-dihydro-1H-pyrazole [3-(R1) and 4-(R2) substituted,
where R1 = H, Ph; R1, R2 = -(CH2)4-, R2 = H] and 5-triclorometyl-5-hydroxy-4,5-
dihydroisoxazole [3-(R1) substituted, where R1 = Ph, 4Br-Ph, tien-2-yl] were reported.
The β-aminovinyl ketones have showed the fragment O=C-C=C-N essentially plane,
as well as, the heterocyclic rings 4,5-dihydropyrazole and 4,5-dihydroisoxazole. The
shorter bond lengths of b-aminovinyl ketones indicated an eletronic resonance effect
in the conjugated system O=C-C=C-N. This effect also was encountered in the
double bond N2=C3 of the rings 4,5-dihydropyrazole and 4,5-dihydroisoxazole and
the substituent of the 3-position of this rings, when this substituent was an aromatic
ring. In general, the molecules studied have its crytalline packing governed by intraand
intermolecular hydrogen bond. / Neste trabalho foi descrito o estudo molecular por difração de raios-X de β-
aminovinil cetonas [R3C(O)CH=C(R1)N(R4R5), onde R3 = CF3, CCl3, CHCl2; R1 = H,
Me; R4 = H; R5 = benzila, Ph, 5-metilisoxazol-3-ila; R4, R5 = -(CH2)4-, -(CH2)2O(CH2)2-
], 1-metilcarboxilato-5-trialometil-5-hidróxi-4,5-diidropirazóis [3-(R1), 4-(R2) e 5-(R3)
substituídos, onde R1 = H, Me; R2 = H, Me; R3 = CCl3, CF3], 1-cianoacetil-5-
trifluormetil-5-hidróxi-4,5-diidropirazóis [3-(R1) e 4-(R2) substituídos, onde R1 = H, Ph;
R1, R2 = -(CH2)4-, R2 = H] e 5-triclorometil-5-hidróxi-4,5-diidroisoxazóis [3-(R1)
substituído, onde R1 = Ph, 4-BrPh, tien-2-ila]. As b-aminovinil cetonas apresentaram
o fragmento O=C-C=C-N e os anéis heterocíclicos, 4,5-diidropirazol e 4,5-
diidroisoxazol, essencialmente planos. Os dados relacionados aos comprimentos de
ligações do sistema conjugado O=C-C=C-N indicaram um efeito de ressonância
eletrônica nas β-aminovinil cetonas. Esse efeito foi encontrado também na ligação
dupla N2=C3 dos anéis 4,5-diidropirazóis e 4,5-diidroisoxazóis e o substituinte da
posição-3 dos mesmos, quando este fosse um anel aromático. De maneira geral, as
moléculas estudadas têm seu empacotamento cristalino governado por ligações de
hidrogênio intra- e intermoleculares.
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Planejamento, síntese e avaliação farmacológica de novos protótipos de fármacos vasorelaxantes / Design, synthesis and pharmacological profile of new lead compounds of vasorelaxant drugsPazini, Francine 24 August 2012 (has links)
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Previous issue date: 2012-08-24 / Cardiovascular diseases are the leading cause of death worldwide, so the search for
cardiotonic drugs more effective, safer and with lower side effects compared to currently
available therapy, is of fundamental importance.
Thus, we used in our design the phosphodiesterase 3 inhibitors, milrinone (13) and
cilostazol (4), which show positive inotropic activity, relaxation effect and vasodilators. The
new heterocyclic compounds (20a-20o) were originally designed by applying molecular
hybridization strategy from these lead-compounds.
The synthetic route to obtain the compounds 20a-20o resulted in overall yields ranging
from 16.2 and 73.4%. During the synthesis, we used the Duff reaction conditions to
formylation of N-phenylpyrazoles (1-phenyl-1H-pyrazole) (9a-o), which was an alternative
synthetic methodology to classic Vilsmeier-Haack conditions. All the synthesized compounds were characterized by infrared and NMR spectroscopy combining the 1H, 13C, HSQC and HMBC correlation spectra. The compounds 20c, 20d, 20e, 20f and 20g, were evaluated for their relaxation profile of vascular smooth muscle. From this preliminary test, the 20d compound was selected to be
further evaluated in pharmacological models, as provided better relaxation among this series of compounds in order to investigate the action mechanism. In these assays, 20d compound showed a relaxing activity in isolated arteries, potentiate by the presence of endothelium, with the participation of routes GCs/GMPc and AC/AMPc and where the flows of K+ and Ca2+through the membrane and the uptake of Ca2+ by the sarcoplasmic reticulum are important. Given the promising pharmacological profile of 20d compound, it was subjected to safety testing in preclinical in vitro model of the neutral red incorporation by cultures of 3T3 cells and acute oral toxicity tests. According to the International Organization for Economic
Cooperation and Development (OECD) 423, the 20d compound was classified in 4 class,
which shows that the compound was tolerated at a dose of 2000mg/kg orally.
At the end of this work, we conclude that the design strategy employed has been
validated, as the 20d compound showed a similar pharmacological profile to lead-compounds milrinone (13) and cilostazol (4). The pharmacological evaluation of all synthesized compounds in this work, will serve as a guide to establish the structure activity relationship of the series, and in turn, lead future changes on the chemical structures of the compounds for the activity cardiotonic optimization. / As doenças cardiovasculares são a principal causa de morte no mundo, logo a busca de
candidatos a protótipos de fármacos cardiotônicos que sejam mais efetivos, seguros e que
apresentem menos efeitos colaterais quando comparados aos já disponíveis na terapêutica, é
de fundamental importância.
Neste contexto, foram empregados em nosso planejamento os protótipos inibidores de
fosfodiesterase 3, milrinona (13) e cilostazol (4), que mostram atividade inotrópica e efeito
vasodilatador. Os novos compostos heterociclos 5-(1-fenil-1H-pirazola-4-il)-2H-tetrazolas
(20a-20o) foram originalmente desenhados através da estratégia de hibridação molecular a
partir destes protótipos.
A rota sintética eleita, composta por quatro etapas, para a obtenção dos compostos 5-(1-
fenil-1H-pirazola-4-il)-2H-tetrazolas (20a-20o) resultou em rendimentos globais que variaram
entre 16 e 73%. Inicialmente ocorreu uma reação de condensação entre as fenilhidrazinas 14a-
14o e 1,1,3,3 tetrametoxipropano, catalisada por ácido clorídrico, com formação dos
intermediários 1-fenil-1H-pirazolas (16a-16o). Na sequência, os compostos 16a-16o foram
submetidos a uma reação de formilação quimio e regioespecífica na posição 4 do anel
pirazola. Os intermediários 1-fenil-1H-pirazola-4-carbaldeído (18a-18o) foram então
submetidos a uma reação de condensação com cloridrato de hidroxilamina que desidratou in
sito na presença de iodeto de potássio aos intermediários 1-fenil-1H-pirazola-4-carbonitrilas
(19a-19o). Ao final, os compostos 19a-19o, através de um processo de cicloadição 1,3 bipolar,
reagiram com azida de sódio formando os compostos desejados 20a-20o.
A utilização das condições da reação Duff para a formilação de N-fenilpirazóis (1-fenil-
1H-pirazol) (9a-o), se mostrou uma metodologia sintética alternativa às condições clássicas
de Vilsmeier-Haack. Todos os compostos sintetizados tiveram suas estruturas químicas
elucidadas através das espectroscopias na região do infravermelho e ressonância magnética
nuclear de 1H, 13C, HSQC e HMBC.
Os compostos 5-[1-(4-fluorfenil)-1H-pirazola-4-il]-2H-tetrazola (20c), 5-[1-(3-
fluorfenil)-1H-pirazola-4-il]-2H-tetrazola (20d), 5-[1-(4-clorofenil)-1H-pirazola-4-il]-2Htetrazola
(20e), 5-[1-(3-nitrofenil)-1H-pirazola-4-il]-2H-tetrazola (20f) e 5-[1-(3-clorofenil)-1H-pirazola-4-il]-2H-tetrazola (20g), foram avaliados quanto ao seu perfil de relaxamento do
músculo liso vascular. A partir deste ensaio preliminar, o composto 5-[1-(3-fluorfenil)-1Hpirazola-
4-il]-2H-tetrazola (20d) foi selecionado para ser avaliado em modelos
farmacológicos complementares, uma vez que apresentou melhor perfil de relaxamento dentre
esta série de compostos, a fim de investigar seu mecanismo de ação. Nestes ensaios, o
composto 20d mostrou uma ação relaxante em artérias isoladas, potencializada pelo endotélio,
com participação das vias GCs/GMPc e AC/AMPc e onde os fluxos de K+ e Ca2+ através da
membrana e a captação de Ca2+ pelo retículo sarcoplasmático são importantes.
Face ao perfil farmacológico promissor do composto 5-[1-(3-fluorfenil)-1H-pirazola-4-
il]-2H-tetrazola (20d), o mesmo foi submetido aos ensaios de segurança pré-clínica no
modelo in vitro de incorporação do vermelho neutro com culturas de células 3T3 e a
toxicidade oral aguda em modelo in vivo. Segundo o protocolo internacional Organization for
Economic Cooperation and Development (OECD) 423 o composto 20d foi classificado na
classe 4, que mostra que o composto foi bem tolerado na dose de 2000 mg/kg por via oral.
Ao término deste trabalho, podemos concluir que a estratégia de planejamento
empregada no mesmo foi validada, uma vez que o composto 5-[1-(3-fluorfenil)-1H-pirazola-
4-il]-2H-tetrazola (20d) apresentou um perfil farmacológico vasodilatador com prováveis
ações cardioativas. A avaliação farmacológica completa, incluindo experimentos com a
enzima fosfodiesterase 3, de todos os compostos sintetizados neste trabalho servirá de guia
para se estabelecer a relação estrutura atividade da série, e por sua vez, conduzir as futuras
modificações sobre as estruturas químicas dos compostos visando à otimização da atividade
cardiotônica.
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Nh-pirazóis e isoxazóis: síntese mecanicamente ativada por grinding / Nh-pyrazoles and isoxazoles: synthesis mechanically activated by grindingLonghi, Kelvis 30 July 2010 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The synthesis of twelve NH-pyrazoles from the cyclocondensation reaction of β-dimethylaminovinylketones ([R1C(O)C(R2)=CHN(Me)2], where R1 = Me, C6H5, 3-
MeO-C6H4, 4-Me-C6H4, 4-MeO-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-O2N-C6H4, fur-2-il, tien-2-il; R2 = H, 2-MeO-C6H4 and R1, R2 = -(CH2)3C(O)- with hydrazine sulfate is reported. In this work, it was also demonstrated the synthesis of twelve isoxazoles from the cyclocondensation reaction of β-dimethylaminovinylketones where R1 = Me, C6H5, 3-MeO-C6H4, 4-Me-C6H4, 4-MeO-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-biphenyl, naphthalen-2-yl, 4-O2N-C6H4, thien-2-yl and R2 = H, 2-MeOC6H4 with hydroxylamine hydrochloride. The reactions were performed in the
presence of p-toluene sulfonic acid as the catalyst through two methodologies: (i) by the solvent-free grinding method, and (ii) using the conventional method, ethanol reflux. In addition, the Grindstone Chemistry methodology demonstrated that largescale synthesis is also possible. Making a comparison with the classical reaction
conditions, which employ molecular solvent (ethanol), the grinding method has as main advantages of shorter reaction time (5-15 min), higher product yields (60-92%),
mild reaction conditions as well as being environmentally friendly. / Neste trabalho é descrita a síntese de uma série de doze NH-pirazóis a partir da reação de ciclocondensação de β-dimetilaminovinilcetonas ([R1C(O)C(R2)=CHN(Me)2], onde R1 = Me, C6H5, 3-MeO-C6H4, 4-Me-C6H4, 4-MeOC6H4,
4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-O2N-C6H4, fur-2-il, tien-2-il; R2 = H, 2-MeOC6H4 e R1, R2 = -(CH2)3C(O)- com sulfato de hidrazina. Também foi realizada a síntese de uma série de doze isoxazóis a partir da reação de ciclocondensação de β-enamino cetonas, onde R1 = Me, C6H5, 3-MeO-C6H4, 4-Me-C6H4, 4-MeO-C6H4, 4-
F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-bifenil, naft-2-il, 4-O2N-C6H4, tien-2-il e R2 = H, 2-MeO-C6H4 com cloridrato de hidroxilamina. As reações para obtenção dos compostos heterocíclicos foram realizadas na presença de ácido p-tolueno sulfônico (ác. p-TsOH) como catalisador através de duas metodologias: (i) utilizando o método grinding na ausência de solvente, e (ii) utilizando metodologia convencional, refluxo em etanol. O método Grindstone Chemistry foi testado e demonstrou que a síntese
em grande escala também é possível. Os resultados obtidos mostraram que o grinding proporciona uma redução no tempo da reação (5-15 min), altos rendimentos (60-92%), condições de reação brandas, além de ser uma metodologia
ambientalmente aceitável.
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1-(2,4-Diclorofenil)-1H-pirazóis: Síntese, Análise Estrutural e Interação com os Receptores Canabinóides CB1 / 1-(2,4-dichlorophenyl-1H-pyrazoles: Synthesis, Structural Analysis and Interactions with Cannabinoid Receptors CB1Machado, Pablo 25 June 2010 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A method to obtain fourteen enones [EtO2CC(O)C(R2)=C(R1)OR, where R = H, Me; R1 = Pr, Ph, 4-MeOC6H4, 4-MeC6H4, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-NO2C6H4, Fur- 2-yl; R2 = H; R1,R2 = -(CH2)3-, -(CH2)4-, -(CH2)5-, -(CH2)6-, 3,4-dihydronaphthalen-2-yl] from acylation of acetals with ethyl oxalyl chloride is reported. The cyclocondensation
reaction of these substrates with 2,4-dichlorophenyl hydrazine hydrochloride under ultrasound irradiation furnished a series of 1-(2,4-dichlorophenyl)-3-ethylcarboxylate-1Hpyrazoles in 71-92% yields. The pyrazole ester derivatives with R1,R2 = -(CH2)3-, -
(CH2)4-, -(CH2)5-, and (CH2)6- suffered hidrolysis reaction in basic media supplied the carboxylic acids (94-97%) which were converted to the corresponding acid chlorides after reaction with thionyl chloride. The reaction of acid chlorides with primary amines (piperidin-1-ylamine, propylamine, 2-morpholino-4-yl-ethylamine, aniline, 4-metoxiphenylamina, 4-nitrophenylamina) led to respective 3-carboxyamide-1-(2,4-dichlorophenyl)-1H-pyrazoles in 85-97% yields. In addition to spectroscopic data the structure of the compounds was studied by X-ray diffraction experiments. Since, the 3-carboxyamide-1-(2,4-dichlorophenyl)-1H-pyrazoles are structurally similar to
Rimonabant, a known antagonist of CB1 receptors, binding assays were performed to the cannabinoid receptor CB1. The most promising ligand and candidate to become prototype was the 1-(2,4-dichlorophenyl)-4,5,6,7,8,9-hexahydro-1Hcycloocta[c]pyrazole-3-carboxylicacid-piperidin-1-ylamide which shifted approximately 100% of [3H]Rimonabant in the tests. / Este trabalho descreve um método para obter catorze enonas
[EtO2CC(O)C(R2)=C(R1)OR, onde R = H, Me; R1 = Pr, Ph, 4-MeOC6H4, 4-MeC6H4, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-NO2C6H4, Fur-2-il; R2 = H; R1,R2 = -(CH2)3-, -(CH2)4-, -
(CH2)5-, -(CH2)6-, 3,4-diidronaftalen-2-il] a partir da acilação de acetais com cloreto de etil oxalila. A reação de ciclocondensação desses substratos com cloridrato de 2,4-
diclorofenil hidrazina utilizando irradiação de ultrassom forneceu uma série de 1-(2,4-diclorofenil)-3-etilcarboxilato-1H-pirazóis em 71-92% de rendimento. Os pirazóis
sintetizados (R1,R2 = -(CH2)3-, -(CH2)4-, -(CH2)5-, -(CH2)6-) sofreram hidrólise em meio básico conduzindo aos respectivos ácidos carboxílicos (94-97%) os quais foram
convertidos aos cloretos de ácido correspondentes após reação com cloreto de tionila. A reação desses cloretos de ácido com aminas primárias (piperidin-1-ilamina,
propilamina, 2-morfolin-4-il-etilamina, anilina, 4-metoxifenilamina, 4-nitrofenilamina) conduziram aos respectivos 3-carboxiamida-1-(2,4-diclorofenil)-1H-pirazóis em 85-97% de rendimento. Adicionalmente aos dados espectroscópicos, a estrutura dos compostos foi estudada por experimentos de difração raios-X. Uma vez que os 3-carboxiamida-1- (2,4-diclorofenil)-1H-pirazóis são estruturalmente análogos ao Rimonabanto, um conhecido antagonista dos receptores CB1, foram realizados ensaios de ligação específica desses compostos para o receptor canabinóide CB1. O ligante mais promissor, candidato a protótipo, foi o 3-carboxiamida-1-(2,4-diclorofenil)-N-(piperidin-1-il)-4,5,6,7,8,9-hexaidro-1H-ciclocta[c]pirazol o qual deslocou, aproximadamente, 100% do [3H]Rimonabanto nos ensaio realizados.
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Fundamental Studies of Copper Corrosion in Interconnect Fabrication Process and Spectroscopic Investigation of Low-k StructuresGoswami, Arindom 12 1900 (has links)
In the first part of this dissertation, copper bimetallic corrosion and its inhibition in cleaning processes involved in interconnect fabrication is explored. In microelectronics fabrication, post chemical mechanical polishing (CMP) cleaning is required to remove organic contaminants and particles left on copper interconnects after the CMP process. Use of cleaning solutions, however, causes serious reliability issues due to corrosion and recession of the interconnects. In this study, different azole compounds are explored and pyrazole is found out to be a potentially superior Cu corrosion inhibitor, compared to the most widely used benzotriazole (BTA), for tetramethyl ammonium hydroxide (TMAH)-based post CMP cleaning solutions at pH 14. Micropattern corrosion screening results and electrochemical impedance spectroscopy (EIS) revealed that 1 mM Pyrazole in 8 wt% TMAH solution inhibits Cu corrosion more effectively than 10 mM benzotriazole (BTA) under same conditions. Moreover, water contact angle measurement results also showed that Pyrazole-treated Cu surfaces are relatively hydrophilic compared to those treated with BTA/TMAH. X-ray photoelectron spectroscopy (XPS) analysis supports Cu-Pyrazole complex formation on the Cu surface. Overall Cu corrosion rate in TMAH-based highly alkaline post CMP cleaning solution is shown to be considerably reduced to less than 1Å/min by addition of 1 mM Pyrazole. In the second part, a novel technique built in-house called multiple internal Reflection Infrared Spectroscopy (MIR-IR) was explored as a characterization tool for characterization of different low-k structures.In leading edge integrated circuit manufacturing, reduction of RC time delay by incorporation of porous ultra low-k interlayer dielectrics into Cu interconnect nanostructure continues to pose major integration challenges. The main challenge is that porous structure renders interlayer dielectrics mechanically weak, chemically unstable and more susceptible to the RIE plasma etching damages. Besides the challenge of handling weak porous ultra low-k materials, a lack of sensitive metrology to guide systematic development of plasma etching, restoration and cleaning processes is the major stumbling block. We explored Multiple Internal Reflection Infrared Spectroscopy and associated IR techniques as a sensitive (sub-5 nm) characterization tool to investigate chemical bonding modification across fluorocarbon etch residues and low-k dielectric interface after plasma etching, ashing, UV curing and post-etch cleaning. The new insights on chemical bonding transformation mapping can effectively guide the development of clean-friendly plasma etch for creating ultra low-k dielectric nanostructures with minimal dielectric damages.
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Fluoromethyl ketone prodrugs: Potential new insecticides towards Anopheles gambiaeCamerino, Eugene 29 June 2015 (has links)
Malaria continues to cause significant mortality in sub-Saharan Africa and elsewhere, and existing vector control measures are being threatened by growing resistance to pyrethroid insecticides. With the goal of developing new human-safe, resistance-breaking insecticides we have explored several classes of acetylcholinesterase inhibitors. In vitro assay studies demonstrate that tri- and difluoromethyl ketones can potentially inhibit An. gambiae AChE (AgAChE). These compounds inhibit the enzyme by making a covalent adduct with the catalytic serine of AChE. Trifluoromethyl ketones however are poor inhibitors of the G119S resistant mutant of AgAChE. However difluoromethyl ketones can inhibit G119S AgAChE and compound 3-10g showed an IC₅₀ value of 25.1 nM after 23h incubation time. Despite this potent inhibition of AgAChE, the tri-, di-, and (mono)fluoroketones showed very low toxicity to An. gambiae, perhaps due to hydration and rapid clearance.
In an attempt to improve An. gambiae toxicity, oximes and oxime ethers of these compounds were prepared as potential prodrugs. These structures identified trifluoromethyl ketone oxime 3-2d as a potent toxin against both wild-type (G3-strain) and a multiply resistant (Akron) strain of An. gambiae. This compound is within 3-fold of the toxicity of propoxur to wild type An. gambiae (LC₅₀ values of 106 and 39 µg/mL, respectively). Most significantly, 3-2d was much more toxic than propoxur to multiply-resistant (Akron) strain An. gambiae (LC₅₀ = 112 and >5,000 µg/mL, respectively). However, thus far we have not been able to link the toxicity of these compounds to a cholinergic mechanism. Pre-incubation studies suggest that significant hydrolysis of these compounds to TFKs does not occur over 22 h at pH 7.7 or 5.5.
The mechanism of action of 3-2d remains unknown. Our enzyme inhibition studies have demonstrated that 3-2d does not hydrolyze to the trifluoromethyl ketone 2-9d at pH 7.7. The high Akron toxicity of 3-2d and poor inhibition of G119S AgAChE by 2-9d argue against enzyme mediated conversion of 3-2d to 2-9d within the mosquito. Thus, we can rule out an AChE inhibition mechanism for toxicity. Additional experiments by our collaborator (Dr. Jeffrey Bloomquist, University of Florida) also rule out inhibition of mitochondrial respiration or agonism of the muscarinic acetylcholine receptor. Future work will address other potential insecticidal modes of action. / Ph. D.
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Small Core Heterocyclic Carbamates and Carboxamides: Resistance-breaking Acetylcholinesterase Inhibitors Targeting the Malaria Mosquito, Anopheles gambiaeVerma, Astha 13 June 2014 (has links)
Malaria is one of the deadliest diseases known to mankind. In 2010, 219 million cases were reported, and 666,000 deaths were attributed to this disease. In the past, pyrethroid-treated mosquito nets have shown efficacy in reducing malaria transmission in many malaria endemic regions. However, an upsurge in the mosquito population that is resistant to pyrethroids threatens to compromise the efficacy of pyrethroid-treated bed nets. In an effort to develop another class of insecticide with a different mode of action, we have explored three classes of five membered heterocyclic carbamates (isoxazol-3-yl, pyrazol-5-yl, and pyrazol-4-yl), and 3-oxoisoxazole- 2(3H)-carboxamide as acetylcholinesterase inhibitors (AChE) targeting wild type (G3) and resistant (Akron) malaria mosquito Anopheles gambiae (Ag). Isoxazole carboxamide and carbamates were obtained regioselectively through judicious use of two different protocols. The final products were characterized and identified using ¹H and ¹³C NMR, and mass spectroscopy. In addition, the carboxamide structure was confirmed using X-ray diffraction. Several of the novel carbamates and carboxamides evaluated exhibited excellent toxicity towards susceptible G3 and resistant Akron strain An. gambiae (48f LC₅₀ G3 = 41 μg/mL, LC₅₀ Akron = 58 μg/mL, and 47i LC₅₀ G3 = 38 μg/mL, LC₅₀ Akron = 40 μg/mL). Hence, achieving the resistance- breaking goal. On the contrary, the commercial aryl methylcarbamates currently approved for indoor residual sprays (IRS) showed no potency towards the resistant strain An. gambiae (LC₅₀ G3 = 16-42 μg/mL, and LC₅₀ Akron >5,000 μg/mL). Further, we observed low toxicological cross-resistance ratios (RR) for the toxic isoxazol-3-yl and pyrazol-4-yl carbamates, and 3- oxoisoxazole-2(3H)-carboxamides (RR = 0.5-2.0). Amongst the commercial AChE inhibitors approved for IRS, only aldicarb exhibited such low RR (RR = 0.5), whereas the RR for commercial aryl methylcarbamates exceed 130-fold. The low RR observed for these novel heterocyclic inhibitors would certainly be favorable for a new anticholinesterase-based mosquitocide targeting both the susceptible and resistant strain mosquitoes. Although the overall selectivity (Ag vs human) did not exceed 24-fold, the heterocyclic carbamates and carboxamides synthesized by the author showed appreciable inhibition of resistant AChE (G119S) in comparison to commercial aryl carbamates, which showed no inhibition at all.
During the course of this project, the isoxazol-3-yl and pyrazol-5-yl methylcarbamates proved to be unstable, and thus could not be isolated. The synthesis of pyrazol-4-yl methylcarbamates using N-methylcarbamoyl chloride proved particularly challenging due to the formation of by-products called allophanates. The similar Rf of the by-product and the desired final product made the isolation laborious and time-consuming. We have successfully overcome this problem by employing a new protocol, where triphosgene served as the carbonylating agent and N-methylamine in THF was used as the amine source. In addition, we have also developed another one-pot protocol for a safer synthesis of pyrazol-4-yl methylcarbamates utilizing 1,1- carbonyldiimidazole (CDI), and N-methylamine hydrogen chloride salt. With the pyrazol-4-yl core, apart from achieving excellent toxicity towards both strains of An. gambiae, we have also achieved excellent AgAChE vs hAChE selectivity (Ag vs h >100-fold). Due to our continued interest in developing this core, we have devised a convenient, scalable, no-column approach for the synthesis an intermediate 103 that can be utilized to synthesize these compounds more efficiently. / Ph. D.
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Mécanismes d'action des composés oestrogéniques dans la neuroprotection chez la souris MPTP = : Neuroprotective mechanisms of estrogenic compounds in MPTP miceAl-Sweidi, Sara 13 April 2018 (has links)
Des études expérimentales faites par notre laboratoire démontrent que le 17β-E₂ a des effets bénéfiques contre le MPTP. On poursuit la recherche de nouveaux composés oestrogéniques comme des agents neuroprotecteurs au cerveau pour prévenir ou combattre la maladie de Parkinson. Ce projet de recherche étudie les effets du 17β-E₂, le PPT et le DPN sur l'expression des ERs ainsi que leurs mécanismes et capacité neuroprotectrice chez la souris MPTP (modèle animal de la maladie). Les résultats démontrent que les ERs sont exprimés dans le cortex, le striatum et l'hippocampe. Les résultats examinant le striatum proposent que les traitements oestrogénique protègent contre la perte des neurones dopaminergiques. Ensuite, une augmentation de l'activité des ERK1 et ERK2 chez les souris MPTP était observé. Le traitement hormonal a normalisé cet effet dans le cas du ERK1 et le contraire est vu pour ERK2. Donc, ces mécanismes neuroprotecteurs impliquent les récepteurs oestrogéniques et la signalisation par les protéines ERK1/2
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