Convenient One-Pot Synthesis of Spirooxindole-4H-pyrans in the Presence of SBA-Pr-NH2 and Evaluation of their Urease Inhibitory Activities

A simple and efficient one-pot three-component synthesis of the biologically important spirooxindole-4H-pyrans was carried out by the reaction of isatin, activated methylene reagents, and 4- hydroxycoumarin in aqueous medium. SBA-Pr-NH2 was found to be an efficient heterogeneous nanoporous solid basic catalyst (pore size of 6 nm) which can be easily handled and removed from the reaction mixture by simple filtration. This method is of great value because of its environmentally benign character, high yield processing, and easy handling. The biological activity of target compounds was screened by evaluation of their urease enzyme inhibition