Abstract
A series of Mannich base derivatives of 2-hydroxy-chalcones were obtained expediently in good to excellent yields by microwave-assisted Mannich reaction. The regioselectivity of the reaction occurred preferentially at the C-3 position of the 2-hydroxy-chalcone backbone. In comparison with conventional results, results from microwave possesses give better yields in shorter times. Further vasorelaxation assay showed that 2-hydroxy-3-((4-methylpiperazin-1-yl)methyl)-4,6-dimethoxymethoxy-3′-bromo-chalcone 8 significantly decreased maximal PE-induced contraction (Emax = 100 ± 5.97%, EC50 = 10.2 ± 0.51 µM).
ACKNOWLEDGMENTS
We thank the College of Science Zhejiang University for 1H NMR, 13C, NMR, and elemental analyses, and the experimental center of the College of Pharmaceutical Sciences Zhejiang University, for supporting the microwave reactor.
Notes
a Ratio of 18 (C3-position product) to 19 (C5-position product) is 3:1.