• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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.
1

Síntese de 3-acil-4-aril-2-(trifluormetil)-2-hidróxi-3,4,7,8-tetraidro-2h-cromen-5(6h)-onas via reações multicomponentes e derivatizações / Synthesis of 3-acyl-4-aryl-2-(trifluoromethyl)-2-hydroxy-3,4,7,8-tetrahydro-2h-chromen-5(6h)-ones via multicomponent reactions and derivatizations

Navarini, Jussara 20 August 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work describes firstly the synthesis of a new series of 3-acyl-4-aryl-2-(trifluoromethyl)-2-hydroxy-3,4,7,8-tetrahydro-2H-chromen-5(6H)-ones (4) (thirty-four examples) through the methodology of multicomponent reactions involving 1,3-ciclohexadione (1), six aryl aldehydes (2) and six 4-alkoxy-4-alkyl(aryl/heteroaryl)1,1,1-trifluoro-3-alquen-2-ones (3) in the presence of triethylamine (30 mol%) in ethanol, with yields of 15-75%. In a subsequent step, were carried out derivatization reactions of trifluoromethyl substituted chromenones since their structures have several reactive sites possible to chemical modification, ie a hemi-acetal function at C2, endo and exocyclic carbonyl, C3 and C5, respectively, and an olefinic double bond conjugaste between C8a and C4a. The chemical derivatizations in chromenones (4) were initiated by partial oxidative aromatization involving iodine and alcohol solvent reaction by using conventional methods and heating via microwave irradiation. These procedures led to a series of 3-acyl-2-hydroxy-4-aryl-5-alkoxy-2-(trifluoromethyl)chromans (eleven examples) in 50-89%yield. Subsequently, reduction reactions of 2-hydroxy-2H-chromenones (4) and chromenes (5) using NaBH4 in ethanol as solvent allowed to obtain of 3-acyl-8a-hydroxy-4-aryl-2-(trifluoromethyl)-octaidrochromen-5-ones (8) (nine examples) and 4-phenyl-2-(trifluoromethyl)-2-hydroxy-3-(1-hydroxyethyl)-5-methoxychroman (9) in 25-63% and 83% yield, respectively. Finally, rearrangement reactions between chromenone ring (4) and hydrazine monohydrate resulted in a new series of 2-[(3(5)-trifluormethyl-5(3)-alkyl/aryl-1H-pyrazole-4-il)-aryl]-3-hydroxyciclohex-2-en-1-one (10) (six examples) to yield 63-90%. An example of the series 10 was subjected to reactions of partial oxidative aromatization and N-alkylation, where aryl = phenyl, and 4-MeOC6H4 and alkyl= Me. The partial aromatization reaction, in the presence of iodine/methanol, conducted to formation of 4-(2,6-dimethoxyphenyl-4-methoxyphenyl)phenylmethyl-5(3)-methyl-3(5)-trifluoromethyl-1H-pyrazole (11) in 72% yield. The N-alkylation reaction of 11 employing benzyl chloride, NaH in DMF at room temperature led to the regioselective (isomer 1,5) and allowed the isolation of 2-[(1-benzyl-5-trifluoromethyl-3-methyl-1H-pyrazole-4-yl)phenylmethyl]-3-hydroxyciclohexen-2-en-1-one (12) with 69% yield. The compounds were characterized by 1H and 13C {1H}, 19F, e 2D HSQC NMR Spectroscopy, Gas Chromatography coupled to Mass Spectrometry (GC-MS), Liquid Chromatography (LC-ESI). Their purity was determined by CHN Elemental Analysis and High-resolution Mass Spectrometry (HRMS). / O presente trabalho descreve, inicialmente, a síntese de uma nova série de 3-acil-4-aril-2-(trifluormetil)-2-hidróxi-3,4,7,8-tetraidro-2H-cromen-5(6H)-onas (4) (34 exemplos), através da metodologia de Reações Multicomponentes (RMCs) envolvendo 1,3-cicloexadiona (1), seis aril aldeídos (2) e seis 4-alcóxi-4-alquil(aril/heteroaril)-1,1,1-triflúor-3-alquen-2-onas (3), na presença de trietilamina (25 mol%) em etanol, com rendimentos de 15 a 75%. Numa etapa posterior, realizaram-se reações de derivatização de cromenonas trifluormetil substituídas (4), visto que suas estruturas possuem vários sítios reativos passíveis de modificações químicas, ou seja, uma função hemi-acetal, carbonilas endo e exocíclica e uma dupla olefínica conjugada entre C4a e C8a. As derivatizações químicas nas cromenonas (4) foram iniciadas pela aromatização oxidativa parcial envolvendo 4 em meio reacional iodo/álcool, utilizando métodos de aquecimento convencional e via irradiação por micro-ondas. Estes procedimentos conduziram a uma série de 3-acil-5-alcóxi-4-aril-2-(trifluormetil)-2-hidróxicromanos (onze exemplos) com rendimento de 50 a 89%. Subsequentemente, reações de redução de 2-hidróxi-2H-cromenonas (4) e cromanos (5) empregando NaBH4 em etanol como solvente permitiram a obtenção de 3-acil-4-aril-2-(trifluormetil)-8a-hidroxioctaidrocromen-5-onas (8) (9 exemplos) e 4-fenil-2-(trifluormetil)-2-hidróxi-3-(1-hidroxietil)-5-metoxicromano (9aa) com rendimentos de 25 a 63% e 83%, respectivamente. Finalmente, reações de rearranjo anelar entre cromenonas (4) e hidrazina mono hidratada, resultou em uma nova série de 2-[3(5)-(alquil/aril)-5(3)-trifluormetil-1H-pirazol-4-il)arilmetil]-3-hidroxicicloex-2-en-1-ona (10) (seis exemplos) com rendimentos de 63 a 90 %. Um exemplar da série 10 foi submetido a reações de aromatização oxidativa parcial e de N-alquilação, onde Arila = Fenila e 4-MeOC6H4 e Alquila = Me. A reação de aromatização parcial, realizada na presença de iodo/metanol, conduziu à formação de 3(5)-trifluorometil-5(3)-metil-4-[(2,6-dimetoxifenil)-(4-metoxifenil)metil]-1H-pirazol (11) em 72 % de rendimento. A reação de N-alquilação em 10, empregando cloreto de benzila, NaH em DMF à tempertura ambiente levou regioseletivamente ao isômero 1,5 e possibilitou o isolamento de 2-[(1-benzil-5-trifluormetil-3-metil-1H-pirazol-4-il)fenilmetil]-3-hidroxicicloexen-2-en-1-ona (12) com 69 % de rendimento. Os compostos foram caracterizados por Espectroscopia de RMN de 1H,13C{1H},19F, e 2D HSQC, Espectroscopia de Infravermelho, Cromatografia Gasosa Acoplada à Espectrometria de Massas (CG-EM), Cromatografia Líquida (CL-IES-), Difração de Raios-X e sua pureza determinada via Análise Elementar CHN e Espectrometria de Massas de Alta Resolução (HRMS).

Page generated in 0.0332 seconds