Application of [PVP-SO3H] HSO4 as Powerful Polymeric-Based Solid Acid Catalyst for Hantzsch Synthesis of Polyhydrohydroquinolin-5(1H)-One

O-Sulfonated poly(vinylpyrrolidonium) hydrogen sulfate ([PVP-SO3H] HSO4) as a powerful solid acid catalyst has been used for the promotion of the synthesis of polyhydrohydroquinolin-5(1H)-one derivatives via four-component Hantzsch condensation under solvent-free conditions. The advantages of this work are use of easy and economical methodology, short reaction times, high yields, selectivity, and easy work-up. Furthermore, this catalyst in reusable at least four times without damage to its catalytic activity.