Microwave-Assisted Three-Component Domino Synthesis ofPolysubstituted 4H-Pyran Derivatives and TheirAnticancer Activity

An efficient microwave-assisted one-pot procedure has been proposed for the synthesis of new 4-aryl-6-(methylamino)-5-nitro-2-(1H-pyrrol-2-yl)-4H-pyran-3-carbonitriles by condensation of 3-oxo-3-(1H-pyrrol-2-yl)propanenitrile with (E)-N-methyl-1-(methylsulfanyl)-2-nitroethenamine and substituted benzaldehydes in the presence of a catalytic amount of piperidine using ethanol as a solvent. The transformation occurs via successive Knoevenagel condensation, Michael addition, and intramolecular cyclization. The proposed procedure is advantageous due to its one-pot mode, short reaction time, simple purification by recrystallization, and excellent yields. The product structure was confirmed using various spectroscopic techniques, including IR,1H and 13C NMR, LC/MS, elemental analysis, and single crystal X-ray diffraction study. The synthesized compounds were evaluated for their anticancer activity against 60 different human cancer cell lines in nine cancer panels, and two compounds were found to be potent against different cell lines.