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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.
1

Síntese de pirazolo[1,5-a]pirimidinas e fluorfenilpirazóis trifluormetilados em ultrassom e síntese e aplicação de [2]rotaxanos / Synthesis of pyrazolo[1,5-a]pyrimidines and fluorophenylpyrazoles trifluoromethylated in ultrasound and synthesis and aplication of [2]rotaxanes

Marzari, Mara Regina Bonini 14 February 2014 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work presents the synthesis of three series of trifluoromethylated heterocycles by using ultrasound irradiation, nomely pyrazolo[1,5-a]pyrimidines, 2,4- difluorophenylpyrazoles and pentafluorophenylpyrazoles. The reactions were performed between trifluoromethylated enones ([CF3C(O)CH=C(R)(OMe], where R = Me, Bu, i-Bu, Ph, 4-MeC6H4, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-IC6H4, thien-2-yl, naphthyl and biphenyl) with three different nucleophiles, nomely (3)(5)-amine-(5)(3)- methylpyrazole, 2,4-difluorophenylhydrazine hydrochloride and pentafluorophenylhydrazine. The trifluoromethylated pyrazolo[1,5-a]pyrimidines were obtained within 5 minutes, giving yields of 61-98 %. The series of 2,4- difluorophenylpyrazoles was obtained in good yields (54-85 %) within 15 minutes by acidifying the reaction medium with PTSA. In the case of the pentafluorophenylpyrazoles, two steps were needed: Firtly the respective 4,5- dihydropentafluorophenylpyrazoles were synthesised and then subsequently submitted to dehydration reactions using PTSA for 15 minutes, giving yields of 54-81 %. The synthesized compounds were identified by 1H and 13C, and by 19F NMR spectroscopy in the some case, mass spectrometry and X-ray diffraction. In some cases homo/heteronuclear spatial interactions involving fluorine atoms have been useful for confirming the identity of the obtained isomer. Another part of this tesis was the synthesis of four mechanically interlocked molecules. Two [2]rotaxanes carrying an ester group in the macrocycle unity were synthesized by using two threads (fumaramide and succinamide derivatives). Once synthesized these [2]rotaxanes were submmited to hydrolysis reactions to give [2]rotaxanes with acid carboxilic group. These macromolecules were synthesized aiming at the formation of MOFs (metal organic frameworks). The synthesis of this compound was carried out by using copper (II) and [2]rotaxane derivative fumaramide. This product was identified by X-ray diffractometry. / Este trabalho apresenta a síntese de três séries de heterociclos trifluorometilados, utilizando irradiação de ultrassom (pirazolo[1,5-a]pirimidinas, 2,4-difluorofenilpirazóis e pentafluorofenilpirazóis). As reações foram realizadas entre enonas trifluorometiladas ([CF3C(O)CH=C(R)(OMe], onde R = Me, Bu, i-Bu, Ph, 4-Me-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-I-C6H4, tien-2-il, bifen-2-il e naftil) e três dinucleófilos diferentes 3-amino-5-metilpirazol, cloridrato de 2,4-difluorofenilhidrazina e pentafluorofenilhidrazina. As pirazolo[1,5-a]pirimidinas trifluorometiladas foram obtidas em 5 minutos de reação com rendimentos de 61-98 %. A série de 2,4- difluorofenilpirazóis foi obtida, acidificando-se o meio de reação com APTS em 15 minutos de reação, e obtendo-se bons rendimentos (54-85 %) no processo. No caso dos pentafluorofenilpirazóis, foram necessárias duas etapas de reação: a primeira a síntese de 4,5-di-idropentafluorofenilpirazóis, e seguida de posterior reação de desidratação utilizando APTS em 15 minutos de reação, obtendo-se produtos com rendimentos de 54-81 %. Após a síntese desses compostos, os mesmos foram identificados por técnicas de RMN de 1H e 13C e de 19F, em alguns casos, espectrometria de massas e difratometria de raios-X. Em alguns casos, através de RMN, foi possível observar interações espaciais do tipo homo/heteronuclear envolvendo átomos de flúor, úteis na confirmação do isômero obtido. Em outra etapa deste trabalho foi desenvolvida a síntese de quatro moléculas mecanicamente entrelaçadas. Foram sintetizados dois [2]rotaxanos com grupamento éster no macrociclo, utilizando dois filamentos lineares (derivados da fumaramida de succinamida). Após a síntese desses [2]rotaxanos, foi realizada a reação de hidrólise dos grupamentos ésteres do macrociclo em grupamento ácidos. Essas macromoléculas foram sintetizadas visando à formação dos MOFs (Redes de metais orgânicas). A síntese desse composto foi realizada utilizando cobre (II) e o [2]rotaxano derivado da fumaramida. Esse produto foi identificado através de difratometria de Raios-X.

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