The catalytic effects of two forms of nano-TiO2, which are prepared via an ordinary or a magnetized process, are investigated in the synthesis of pyridine dicarbonitriles by one-pot multicomponent reaction of 4-methyl thiophenol, malononitrile, and aryl aldehydes. The results have shown that both prepared nano- TiO2 exhibited high catalytic activities toward the synthesis of pyridine dicarbonitrile derivatives but the nano-TiO2, which is prepared via a magnetized process, has shown better catalytic activity. Furthermore, this new catalytic method for the synthesis of pyridine dicarbonitriles provides rapid access to the desired compounds in high yields and so a simple work-up procedure in the presence of water at room temperature. Therefore, this method represents a significant improvement incompatible of the other methods that are available for the synthesis of pyridine dicarbonitriles.

Keywords