Design, Synthesis, Characterization, and Antimicrobial Activity of Biginelli Products of Indandione

A simple and efficient method has been developed for the synthesis of 4‐(substituted phenyl)‐3,4‐dihydro‐1H‐indeno [1,2‐d] pyrimidine‐2,5‐dione (5) and 4‐(substituted phenyl)‐2‐thioxo‐1,2,3,4‐tetrahydroindeno [1,2‐d] pyrimidine‐5‐one (6) , by a one‐pot three component cyclocondensation reaction of 1,3 dicarbonyl compound (Indandione) (1) , aromatic aldehyde (2) , and urea/thiourea (3/4) using catalytic amount of conc. HCl in refluxing ethanol. Representative samples were screened for their antimicrobial activity against gram‐negative bacteria, E coli and Paeruginosa and gram‐positive bacteria, S aureus , and C diphtheriae using disc diffusion method. The structures of the products were confirmed by IR, 1 H, 13 C NMR, and elemental analysis.