One-Step, Three-Component Synthesis of Highly Substituted Pyridines Using CuFe2O4@SO3H as Reusable Catalyst

Abstract

The synthesis of ‘privileged medicinal scaffolds’ is highly important as these compounds often act as ligands for a number of functionally and structurally diverse biological receptors, and consequently, serve as a platform for developing pharmaceutical agents for diverse applications. Among them, 2-amino-3,5-dicarbonitrile-6-sulfanylpyridines exhibit various pharmacological activities and are useful as antihepatitis B virus, antiprion, antibacterial, and anticancer agents, and as potassium channel openers for treatment of urinary incontinence. Moreover, some of these compounds were found to be highly selective ligands for adenosine receptors, implicated Parkinson’s disease, hypoxia/ischemia, asthma, kidney disease, and epilepsy. These vast applications have inspired the development of a number of methods for the preparation of pyridine derivatives. however, literature studies reveal that most of the methods involve multistep sequences and low isolated yields, use of toxic and expensive catalysts, and lack generality. The synthesis of pyridines a through multicomponent reaction (MCR) of aldehydes, malononitrile, and thiols has recently attracted much attention owing to excellent synthetic efficiency, intrinsic atom economy, high selectivity, procedural simplicity, and environmental friendliness [1-3]. In conclusion, we have demonstrated an efficient and general procedure for the synthesis of 2-amino-3,5-dicarbonitrile-6-sulfanylpyridines via multicomponent reaction of aldehydes, malononitrile, and thiols using of CuFe2O4@SO3H as a very mild, effective, environmentally benign, and reusable catalyst.