32 research outputs found
Synthesis and Analgesic Activity of η6-(Anisole)- Triscarbonyl-Chromium(0)
The general method for synthesis the η6-(arene)-triscarbonyl-chromium(0) complexes was modified and applied for preparation of η6-(anisole)-triscarbonyl-chromium(0) and the study of its analgesic activity was undertaken. A significant analgesic activity was observed after intraperitoneal injection, in Wistar rats. Two doses (30 and 50 mg/Kg of the body weight) of η6-(anisole)- triscarbonyl-chromium(0) were injected and the analgesic activity was evaluated by the Hot Plate Test method. They showed a significant analgesic effect in comparison with the control group and the group treated with dipyrone standard, but not so high when compared with the group treated with morphine standard. Overall, it was observed that the η6-(anisole)- triscarbonyl-chromium(0) was easily obtained by the modified synthetic method and was effective in increasing the pain threshold
Síntese de sulfadiazina e sulfadiazina de prata em escala semi-micro: prática experimental em síntese de fármacos
Ferrocene: 50 Years of Transition Metal Organometallic Chemistry — From Organic and Inorganic to Supramolecular Chemistry
Síntese de reatividade de complexos de ferro com ligantes homocíclicos de caráter aromático
Este trabalho contêm: uma pequena revisão geral dos aspectos históricos, estruturais e mecanísticos da química dos complexos de metais de transição com ligantes deslocalizados de caráter aromático; uma revisão completa da reatividade e dos métodos de preparação desses compostos organometalados, bem como, o estudo e desenvolvimento de novos métodos e técnicas otimizadas, para síntese de: - Sais de (n6-areno) (n5-ciclopentadienil) ferro (II) (sais de arenocínio) - Monocloromercúrioferroceno - Ácidos ferrocenocarboxílicos - Acilferrocenos. Pela primeira vez, foram obtidos sais de arenocínio suficientemente bem cristalizados para estudos cristalográficos por difração de RX. Além de métodos sintéticos, incluímos alguns dados experimentais e estudos iniciais, sobre uma nova oxidação de ferroceno por nitrocompostos, em presença de ácidos de Lewis. Foram obtidos e caracterizados vinte e oito compostos, dentre eles, oito conhecidos: - Um derivado funcional orgânico preparado para fins de caracterização de outro composto; - Um cátion organometálico, anteriormente somente conhecido em solução, por nós isolado no estado sólido. - Seis intermediários chave em química organometálica sintética, preparados por técnicas novas ou otimizadas. Os vinte compostos novos incluem: doze novos sais de nove cátions organometálicos importantes e conhecidos. Dois novos sais de cátions cuja síntese foi publicada durante a elaboração da Tese. Quatro sais de arenocínio totalmente novos. Dois novos ferrocenos acilados. Os métodos por nós desenvolvidos são vantajosos em relação às rotas sintéticas existentes em termos de rendimento, estabilidade do produto isolado, e tornam mais simples a purificação e caracterização estrutural de produtos organometálicos instáveis. Em nossos estudos, atribuímos as bandas de estiramento anti-simétrico da ligação ferro-anéis, e \"vibração de anéis\" (\"ring-tilt\" ), ativas na região infravermelha. Estas bandas, características de estrutura \"Sandwich\", não haviam sido estudadas anteriormente no sistema organometálico (n6-areno) (n5-ciclopentadienil) ferro (II).This thesis contains an abbreviated general review of historical, structural and mechanistic aspects of the chemistry of complexes of transition metals with electron-delocalized aromatic type ligands. It contains also a complete review of the preparative methods and of the reactivity of these organo-metallic compounds. It reports also studies directed to the development of new methods and optimization of techniques for the synthesis of: - (n6-arene) (n5-cyclopentadienyl) iron (II) salts (arenocinium salts) - Monochloromercuri-ferrocene ferrocene carboxylic acids - Acylferrocenes. A description is given for the obtention, for the first time, of arenocinium salts sufficiently well crystallised as to permit crystallographic studies by X-ray diffraction. The thesis contains details of synthetic methods used and also some experimental details of an initial study of a new oxidation of ferrocene by nitro compounds in the presence of Lewis acids. The preparation and characterization of 28 compounds are described, of which only 8 are compounds previously reported. Even so, of these 8 compounds: a) One had been isolated merely as a functional derivative for the caracterization of a different compound. b) One was previously know only in solution, whereas it has now been isolated in the solid state and characterized. c) The remaning 6 are key intermediates in synthetic organometallic chemistry and they have now been preparated by new routes or by optimized techniques. The 20 new compounds include: New salts of nine important organometallic cations previously reported. Two are new salts of organometallic cation derivatives whose synthesis was published during the course of this work four are totally new arenocinium salts. Two are new acylated ferrocenes. The synthetic methods which have been developed and now reported are advantageous in comparison with existing methods in terms of yields, the stability of products isolated and because they simplify the purification and structural characterization of unstable organo-metallic products. The spectrometric data presented include the attribution of the stretching frequency, ln the infra-red spectra, of the ring to iron bonds and the ring tilt vibration frequencies. These infra-red bands, characteristic of sandwich compounds, had not previously been studied in the (n6-arene) (n5-cyclopentadienyl) iron (II) system
POTASSIUM BOROHYDRIDE: IMPROVED USE AS A REDUCING AGENT FOR ORGANIC AND ORGANOMETALLIC KETONES
Analysis of the molecular association of rifampicin with hydroxypropyl-²-cyclodextrin
Foram preparados complexos de inclusão de rifampicina (RP) com hidroxipropil-²-ciclodextrina (HP²CD). A solubilidade da RP em água aumentou linearmente com a concentração de ciclodextrina na faixa de concentração utilizada no diagrama de solubilidade. Os resultados foram analisados quantitativamente através do modelo de Higuchi e Connors. Os valores da constante de estabilidade (K) para o complexo RP/HP²CD em pH 6,9 foram 18 e 120-125 M-1 para as forças iônicas 0,01 e 0,18 M, respectivamente. A análise dos dados de deslocamento químico de ¹H e 15N-NMR para a RP livre e do complexo de inclusão RP/HP²CD revelou que somente os picos da cadeia lateral relacionada com o anel piperazina modificaram substancialmente, provavelmente devido à interação desta região da molécula da RP com a cavidade hidrofóbica da HP²CD. Com base no estudo de modelagem molecular foi proposta a estrutura otimizada para o complexo de inclusão RP/HP²CD. A estrutura proposta está de acordo com os resultados dos espectros de ¹H e 13C-NMR e 15N-NMR .Inclusion complexes of rifampicin (RP) were prepared with hydroxypropyl-²-cyclodextrin (HP²CD). The aqueous solubility of RP increased linearly with cyclodextrin concentration in all range of the solubility diagram. The data was analyzed using the framework of Higuchi and Connors. The stability constant (K) values for RP/HP²CD complex at pH 6.9 were 18 and 120-125 M-1 for ionic strength 0.01 and 0.18M, respectively. The analysis of the chemical shift data of ¹H and 15N for free RP and RP/HP²CD inclusion complex reveal that only peaks of the side chain related to the piperazine ring of RP change substantially, probably due to interaction of this region of RP molecule with the hydrophobic core of HP²CD. We also postulated the optimized structure of RP/HP²CD inclusion complex using molecular modelling study. We found that the postulated structure was in agreement with ¹H and 13C-NMR and 15N-NMR spectra.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
