Sulfonic acid–functionalized Wang resin (Wang-OSO₃H) as polymeric acidic catalyst for the ecofriendly multicomponent synthesis of polyhydroquinolines via Hantzsch condensation

ABSTRACT

An efficient and green approach has been developed for the synthesis of polyhydroquinoline derivatives via Hantzsch condensation reaction directly from corresponding substituted aromatic and aliphatic aldehydes, β-keto compounds, active methylene compounds, and ammonium chloride using recyclable polymer-supported sulfonic acid catalyst under aqueous conditions. Environmental acceptability, operational simplicity, low cost, excellent functional group compatibility, and high yields are the important features of this protocol.

GRAPHICAL ABSTRACT

KEYWORDS:

• Green chemistry
• Hantzsch condensation
• polyhydroquinoline derivatives
• reusable catalyst
• Wang-OSO₃H
• water

Acknowledgments

The authors thank Vilas Dahanukar, Upadhya Timmana, H. Rama Mohan, and the analytical group of CPS-DRL for spectral data. A. V. D. Rao thanks the CPS-DRL (DRL Communication no: IPDO IPM-00510), Hyderabad, India, for encouragement.