Efficient Synthesis of Novel Pyranoquinoline Derivatives from Simple Acetanilide Derivatives: Experimental and Theoretical Study of their Physicochemical Properties using DFT Calculations

Zohreh Mirjafary, Hamid Saidian, Morteza Sahandi, Leila Shojaei
2014 Journal of the Brazilian Chemical Society  
Uma reação conveniente para sintetizar piranoquinolinas úteis a partir de derivados de 2-cloroquinolina-3-carbaldeído e dimedona na presença de KF-Al 2 O 3 é descrita. Rendimentos razoáveis (41-50%), matérias-primas facilmente encontradas e catalisador eficiente pouco caro são os destaques deste método. Foi proposto um mecanismo de reação. A atribuição dos deslocamentos químicos foi feita com ajuda de cálculos de teoria do funcional da densidade (DFT). Os deslocamentos químicos de ressonância
more » ... os de ressonância magnética nuclear (NMR) calculados têm boa concordância com dados experimentais. Valores de deslocamento químico independente de núcleo (NICS) foram usados como medida quantitativa do caráter aromático relativo de piranoquinolinas. Os valores calculados de NICS do grupo fenila de compostos piranoquinolínicos são menores que aqueles do benzeno. A convenient reaction of 2-chloroquinoline-3-carbaldehyde derivatives and dimedone in the presence of KF-Al 2 O 3 for the synthesis of useful pyranoquinolines is described. Reasonable yields (41-50%), easily available starting materials and less expensive efficient catalyst are the key features of the present method. A mechanism was proposed for the reaction course. Attribution of the chemical shifts was made with the help of the density functional theory (DFT) calculations. The computed nuclear magnetic resonance (NMR) chemical shifts are in good agreement with available experimental data. The nucleus-independent chemical shift (NICS) values were used as quantitative measures for the relative aromatic character in pyranoquinolines. The calculated NICS values obtained for the phenyl group of pyranoquinoline compounds are smaller than that of benzene.
doi:10.5935/0103-5053.20140103 fatcat:vfw3mbgnsre47emsyxk4zlc444