Poly(4-vinylpyridinium)hydrogen sulfate: An efficient heterogeneous catalyst for the one-pot synthesis of polyhydroquinolines via unsymmetrical Hantzsch reaction in aqueous medium

A facile and highly efficient protocol for the synthesis of polyhydroquinolines via Hantzsch multicomponent condensation of dimedone, aryl/heteryl aldehydes, ethylacetoacetate and ammonium acetate utilizing poly(4-vinylpyridinium)hydrogen sulfate as a catalyst in aqueous medium has been described. The method offers several advantages such as high yield, short reaction time, simple workup, easy separation of the catalyst and its reusability.