Organocatalyst 1,4-diazabicyclo [2.2.2]Octane (DABCO)-Catalyzed Sustainable Synthesis of Bis-Thiazolidinones Derivatives and their Spectral and DFT Analysis

: Organocatalyst 1,4-diazabicyclo [2.2.2]octane (DABCO) has proven to be an efficient and environmentally friendly catalyst in the multicomponent reaction involving aldehydes, ethylenediamine, and thioglycolic acid under microwave conditions. DABCO stands out among other organic catalysts due to its costeffectiveness, non-toxic nature, and environmentally conscious profile. The method employed in this study exhibited exceptional attributes, such as high yields, swift reaction times, atom economy, catalyst reusability, and minimal catalyst loading. Additionally, there were excellent yields of products (90-94%). The melting points, UV-Vis, IR, 1HNMR, 13CNMR, were used to analyze the produced compounds. The in-vitro antibacterial activity of the synthesized compounds was investigated against pathogenic strains E. coli and Bacillus supstalis, and the results obtained were further explained with the help of DFT and molecular orbital calculations. Moreover, the compound 4b was found to be the most potent antibacterial agent amongst all tested compounds. result: Bis-thiazolidinones derivatives have been synthesized in excellent yields (90–94%) by mixing of aldehydes (2 mmol), ethylenediamine (1 mmol), thioglycolic acid (2 mmol), using DABCO (0.5 mmol), in 8 to 10 minutes under microwave irradiation.