Derivados de 2H-cromen-2-onas acoplados a L-aminoácidos via reação de Ullmann empregados na síntese de 1,3,4-oxadiazóis 2,5-dissubstituídos

• Ano de defesa: 2014
• Autor(a) principal: Maia, Renata Avena
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; Química; UFSM; Programa de Pós-Graduação em Química; Centro de Ciências Naturais e Exatas
• Palavras-chave em Português: Química; Fluorescência; Aminoácidos; Química orgânica; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/22389

In the following work, an unprecedented series of 2,5- disubstituted 1,3,4- oxadiazole 3 was synthesized from 2H-chromen-2-ones-L-amino acids derivatives 1, targeting the union of 2H-chromen-2-one, L-amino acid and 1,3,4-oxadiazole pharmacophoric centers. The synthesis of 2H-chromen-2-ones-L-amino acids derivatives 1a-d was performed by Ullmann coupling reaction between 6-halogen- 2H-chromen-2-one and an L-amino acid, providing a novel of products in yields of 44-78%. The amino acids used in this synthesis were L-valine, L-isoleucine, Lphenylalanine and L-methionine, leading to products 1a, 1b, 1c and 1d, respectively, where compound 1a showed antifungal activity. The 2,5-disubstituted 1,3,4- oxadiazole 3 were obtained from the reaction between 2H-chromen-2-ones-L-amino acids derivatives 1a-d and benzoyl hydrazides 2a-d (a = benzohydrazide, b = 4- tolyl-hydrazide, c = 4-methoxy- benzohydrazide, d = 4-bromo-benzohydrazide), with yields of 16-72 %. All 1,3,4-oxadiazoles showed fluorescence activity and compounds 3aa, 3ab and 3ac showed antibacterial activity.