Ceric ammonium nitrate catalyzed one-pot three-component microwave-assisted synthesis of indole-substituted fused pyrimidine and pyridine derivatives.

The study investigates the synthesis of fused pyridine and pyrimidine derivatives known for their diverse biological activities and structural versatility which serve as pivotal building blocks in organic synthesis. A series of indole-substituted cyanamide derivatives were synthesized by one-pot three-component cyclo-condensation between Indole-3-carboxaldehyde, malononitrile, and electron-rich aromatic and heterocyclic amines by employing several methods such as grinding, microwave irradiation and conventional reflux in the presence of ceric ammonium nitrate and DMF. The nuclei differ concerning the heterocyclic amines such as pyridine, pyrimidine, pyrazine, thiazole, and tetrazole. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, and Mass spectra. The reaction proceeds via Knoevenagel condensation, Michael addition, and intramolecular cyclization. The employed methodology offers the convenient advantages of cascade one-pot condensation, easy isolation, short reaction time, and excellent yield (83–95%). [Display omitted] [ABSTRACT FROM AUTHOR]