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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 Penta-2,4-dienonitrilas e 2-Cianometileno-but-3-enoatos de Etila via Olefinação de Horner-Wadsworth-Emmons e sua Aplicação na Obtenção de 4-Trifluormetil-piridin-2(1H)-iminas Substituídas e 2H-Piran-2-onas Análogas . / "Synthesis of Penta-2,4-dienenitriles and Ethyl 2-Cyanomethylene-but-3- enoates via Horner-Wadsworth-Emmons olefination and their Application to Obtaining Substituted 4-Trifluoromethyl-pyridin-2(1H)-imines and 2H-Pyran-2- ones Analog".

Bencke, Carlos Eduardo 26 March 2013 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / This paper presents the Horner-Wadsworth-Emmons olefination applied to preparing 22 new 5-alkoxy-3-trifluoromethyl-penta-2,4-dienenitriles (5), 5- phenylthio-3-trifluoromethyl-penta-2,4-dienenitriles (6) and ethyl 4-alkoxy-2- cyanomethylene-but-3-enoates (7) from the condensation between diethyl cyanomethylphosphonate (4) and β-alkoxyvinyl ketones (1), β-phenyltiovinyl ketones (2) and ethyl 4-alkoxy-2-oxo-but-3-enoates (3), furnishing the desired products with 10 to 93% yields. In a second step, this paper presents a simple and accessible novel synthetic route, for the preparation of a series of 30 unpublished 1,6- disubstituted 4-trifluoromethyl-pyridin-2(1H)-imines (14-19) from the condensation reaction of 5-aryl-3-trifluoromethyl-5-methoxy-penta-2,4- dienenitriles (Ar = Ph, 4-F-C6H4, 4-Br-C6H4, 4-Me-C6H4 and 4-MeO-C6H4) (5) with primary amines R-NH2 (R = Bu, 2-(1-cyclehexenil)ethyl, 2-(4- morpholinyl)ethyl, 2-phenethyl-ethyl, 2-(4-chlorophenethyl)ethyl and 2-(4- methoxyphenethyl)ethyl) (8-13), in a solvent free sealed system to give the expected products with yields between 20 to 98%. In addition, a series of new 6-substituted 4-trifluoromethyl-2H-pyran-2- ones (20) was obtained in 88 to 100% yeld, from the autocondensation reaction of 5-aryl-3-trifluoromethyl-5-methoxy-penta-2,4-dienenitriles (Ar = Ph, 4-F-C6H4, 4-Br-C6H4, 4-Me-C6H4 and 4-MeO-C6H4) (5), in a reflux system using water as solvent in the presence of HCl and 1 equivalent of ZnBr2. The pyridinimines, pyranones and dienes obtained in this work were identified and characterized by Hydrogen Nuclear Magnetic Resonance (H1NMR), Carbon-13 Nuclear Magnetic Resonance (C13 NMR), Mass Spectroscopy (GC-MS-EI), High Resolution Mass Spectroscopy (HRMS-ESI) and Elemental Analysis. / Este trabalho apresenta a metodologia de olefinação Horner-Wadsworth- Emmons aplicada de maneira inédita na preparação de 22 novas 5-alcóxi-3- trifluormetil-penta-2,4-dienonitrilas (5), 5-feniltio-3-trifluormetil-penta-2,4- dienonitrilas (6) e 4-alcóxi-2-cianometileno-but-3-enoato de etila (7) a partir da reação entre cianometilfosfonato de dietila (4) e respectivas β-alcoxivinil cetonas (1), β-feniltiovinil cetonas (2) e 4-alcóxi-2-oxo-but-3-enoatos de etila (3), levando a formação dos produtos com rendimentos entre 10 e 93%. Numa segunda etapa, este trabalho apresenta uma nova rota sintética, simples e acessível, para a preparação de uma série de 30 inéditas 4- trifluormetil-piridin-2(1H)-iminas 1,6-dissubstituídas (14-19) a partir da reação de condensação entre os 5-aril-3-trifluormetil-5-metóxi-penta-2,4-dienonitrilas (Ar = Ph, 4-F-C6H4, 4-Br-C6H4, 4-Me-C6H4 e 4-MeO-C6H4) (5) com aminas primárias R-NH2 (R = Bu, 2-(1-cicloexenil)etila, 2-(4-morfolinil)etila, 2-fenetiletila, 2-(4-clorofenetil)etila e 2-(4-metoxifenetil)etila) (8-12), em um sistema fechado e sem solvente, obtendo os produtos esperados com rendimentos de entre 20 e 98%. Em outra etapa do trabalho, foram obtidas 4-trifluormetil-2H-piran-2-onas 6-substituídas (20) a partir da reação autocondensação de 5-aril-3-trifluormetil- 5-metóxi-penta-2,4-dienonitrilas (Ar = Ph, 4-F-C6H4, 4-Br-C6H4, 4-Me-C6H4 e 4- MeO-C6H4) (5), em um sistema de refluxo utilizando água como solvente, na presença de HCl e 1 equivalente de ZnBr2, obtendo-se os produtos esperados com rendimentos entre 88 e 100%.As piridiniminas, piranonas e dienos obtidos neste trabalho foram identificados e caracterizados por Ressonância Magnética Nuclear de Hidrogênio (RMN H1), Ressonância Magnética Nuclear de Carbono-13 (RMN C13), Espectroscopia de Massas (CG-MS-EI), Espectroscopia de Massas de Alta Resolução (HRMS-ESI) e Análise Elementar.

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