Multi-Step Synthesis of Biologically Active Novel N-Benzyl-3,5-Bis(Arylidene)-Piperidin-4-Ones and Some Derived Bicyclic and Tricyclic Ring Systems as Macromolecules

Abstract

This study reports the synthesis of some new bicyclic and tricyclic heterocyclic macromolecules incorporated pyrano[3,2-c]pyridine, 1,6-naphthyridine, and pyrimidonaphthyridine rings starting from new dienones, N-benzyl-3,5-bis(arylidene)-piperidin-4-ones. The chemistry involved the cyclocondensation of dienones with malononitrile in the presence of piperidine yielded the target 2-aminopyranopyridine-3-carbonitriles. The reaction of dienones with malononitrile or ethyl cyanoacetate in the presence of excess ammonium acetate afforded the corresponding 2-aminonaphthyridines and/or 2-oxonaphthyridine derivatives, respectively, in good yields. The 2,4-disubstituted pyrimido[4,5-b][1,6]naphthyridines were successfully achieved from the reaction of the 2-aminonaphthyridine derivatives with the appropriate reagents. The structures of the isolated products were determined by elemental analysis and spectral methods (FT-IR, ¹H-NMR, and ¹³C-NMR). The cytotoxicity of some of the prepared derivatives was also investigated.

Graphical Abstract

Keywords:

• Anticancer activity
• dienones
• naphthyridine
• pyranopyridine
• pyrimidonaphthyridine

Acknowledgments

The authors are deeply thankful to the authorities of the Bioassay-Cell Culture laboratory, in vitro bioassays on human tumor cell lines for drug discovery unit, National Research Centre (NRC), Cairo, Egypt, for their efforts in performing the MTT cytotoxicity assay.

Disclosure statement

The authors declare no conflict of interest.