Synthesis of Some Spiro Indeno[1,2-b]pyrido[2,3-d]Pyrimidine-5,3′- Indolines as New Urease Inhibitors

New series of spiroindeno[1,2-b]pyrido[2,3-d]pyrimidine-5,3′-indolines as new urease inhibitors were synthesized by the catalytic procedure in high yield and short reaction time. In this method, biacidic carbon was prepared as a novel heterogeneous acid and was subsequently used as an efficient catalyst in this synthesis. The inhibitory activities of synthesized compounds were tested against Jack bean urease using Berthelot colorimetric assay and docking simulation using AutoDock 4.2. The compound 4a with IC50 =1.94 µM has the most inhibitor activity in this study. Other derivatives such as 4b, 4d, 4e and 7a were found to be more potent urease inhibitors than the standard inhibitor hydroxyurea, yielding IC50 values of 4.35, 5.557, 7.44, 2.81 and 14.46 μM, respectively (IC50 of hydroxyurea = 100 μM).