Dissertação
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
Fecha
2014-02-28Autor
Maia, Renata Avena
Institución
Resumen
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.