New insights in the discovery of novelh-MAO-B inhibitors: structural characterization of a series ofN-phenyl-4-oxo-4H-chromene-3-carboxamide derivatives

• Autor(a) principal: Gomes, Ligia R.
• Data de Publicação: 2015
• Outros Autores: Low, John Nicolson, Cagide, Fernando, Chavarria, Daniel, Borges, Fernanda
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10284/8167
• topic: Crystal structure; Drug design; Chromones; Conformation; Supra­molecular structure; Hydrogen bonding

Six N-substituted-phenyl 4-oxo-4H-chromene-3-carboxamides, namely N-(2-nitro­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10N2O5 (2b), N-(3-meth­oxy­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO4, (3a), N-(3-bromo­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H10BrNO3, (3b), N-(4-methoxy­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO4, (4a), N-(4-methyl­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO3, (4d), and N-(4-hy­droxy­phen­yl)-4-oxo-4H-chromene-3-carboxamide, C16H11NO4, (4e), have been structurally characterized. All compounds exhibit an anti conformation with respect to the C—N rotamer of the amide and a trans-related conformation with the carbonyl groups of the chromone ring of the amide. These structures present an intra­molecular hydrogen-bonded network comprising an N—H⋯O hydrogen bond between the amide N atom and the O atom of the carbonyl group of the pyrone ring, forming an S(6) ring, and a weak Car—H⋯O hydrogen bond in which the carbonyl group of the amide acts as acceptor for the H atom of an ortho-C atom of the exocyclic phenyl ring, which results in another S(6) ring. The N—H⋯O intra­molecular hydrogen bond constrains the carboxamide moiety such that it is virtually coplanar with the chromone ring.