Trisodium citrate dihydrate catalyzed one-pot pseudo four-component synthesis of fully functionalized pyridine derivatives

Abstract

A facile and convenient method has been developed for the one-pot pseudo-four component synthesis of fully functionalized pyridine derivatives from the reactions of aromatic aldehydes, malononitrile and thiols in the presence of a catalytic amount of trisodium citrate dihydrate as an efficient metal-free catalyst in aqueous ethanol under refluxed conditions. All the reactions were completed within just 45 minutes and the desired products afforded in excellent yields (90–95%). Gram scale production of the desired compound was also achieved. Synthesis of biologically promising scaffolds, high atom economy, excellent yields, use of metal-free catalyst, less toxic solvents, no column chromatographic purifications, reusability of the solvent media, multiple carbon-carbon and carbon-heteroatom bond formations are some of the major advantages of this newly developed protocol.

Graphical Abstract

Keywords:

• Fully functionalized pyridines
• metal-free synthesis
• multicomponent reactions
• sustainable developments
• trisodium citrate dihydrate

Acknowledgements

Dr. B. Banerjee is thankful to the Akal University, Talwandi Sabo, Punjab, India and the Kalgidhar Trust, Baru Sahib, Himachal Pradesh, India for the support. Authors are grateful to AMRC, IIT Mandi, Himachal Pradesh, India for the spectral measurements such as ¹H and ¹³C NMR, HRMS and single X-ray crystal data.

Disclosure statement

The authors declare no conflict of interest