Ammonium iodide-promoted cyclization of ketones with DMSO and ammonium acetate for synthesis of substituted pyridines
作者:Xiaojun Pan、Qiao Liu、Liming Chang、Gaoqing Yuan
DOI:10.1039/c5ra07584j
日期:——
A simple and efficient method has been developed for the synthesis of symmetrical and unsymmetrical pyridines via NH4I-promoted cyclization of ketones with DMSO and NH4OAc. It was found that methyl ketones always gave selective formation of the unsymmetrical pyridine, while non-methyl ketones gave unpredictable results (symmetrical or non-symmetrical product only, or a mixture of the two). In addition
planarity by the ethylene bridge. As a result, efficient π-conjugation was maintained throught the molecule. UV–visibleabsorption and fluorescence spectra of THDP became shifted to longer wavelengths upon substitution of different moieties at 5-Aryl position. A maximum of 200 nm red-shifted fluorescence with respect to parent compound was observed for the nitro substituent. However, tradeoffs in spectral