| Hetercyclics represent an important class of compounds for their biological activity and medical value. The synthesis of these compounds remains a hot topic of people's attention. In recent years multicomponent reactions (MCRs) have been extensively studied for their simple procedures, efficiency and superior atom economy. This reaction which referred to as one-pot synthesis of three or more than three starting materials provides a powerful tool towards the rapid synthesis of diverse and complex heterocyclic compounds. In this work we developed a series of multicomponent reactions for synthesis of hetercyclic compounds and obtained some interesting results.1. Polysubstituted pyridines and 1,4-dihydropyridines were prepared in a three-component reaction of aromatic aldehyde, malononitrile and aliphatic amine in a mixed solvent of methanol and water. The structures of amine play a determining factor for the formation of different products. All products were characterized by IR, 1H NMR, 13 CNMR, LC-MS spectroscopy. The single crystal structure of one polysubstituted pyridine was determined by X-ray diffraction method. 2. A series of furans or pyrans as well as some tetraketones were synthesized via one-pot reaction of aromatic aldehydes with 5,5-dimethylcyclohexane-1,3-dione and cyclohexane-1,3-dione in the presence of 1,4-Diazabicyclo[2.2.2]octane (DABCO). All the products were characterized by IR, 1H NMR, 13 CNMR, LC-MS spectroscopy. The single crystal structures of two products were determined by X-ray diffraction method.3. The interesting zwitterionic compounds were synthesized by the multicomponent reactions of N-pyridylacetyl pyridinium salt, aromatic aldehydes, Medrum acid or 1, 3-dimethylbarbituric acid at room temperature using triethylamine as base catalyst. All the products were characterized by IR, 1H NMR, 13 CNMR, LC-MS spectroscopy. The single crystal structure of one representative zwitterionic salt was determined by X-ray diffraction method.
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