Investigation of the Biological Activity of Pyrrolo[1,2-a]imidazole Derivatives Produced by a Green One-Pot Multicomponent Synthesis of Ninhydrins.

Aims & Objective: This study entailed the creation of a new variation of pyrroloimidazoles with exceptional efficacy through chemical synthesis. The synthesis was accomplished by tricomponent reactions utilizing ninhydrins, diamines, and activated acetylenic compounds in an aqueous setting, leading to significant yields. The antioxidant properties of recently synthesized Pyrroloimidazoles derivatives have been ascribed to the existence of NH and OH groups, which were evaluated using two techniques. The antimicrobial effectiveness of recently developed pyrroloimidazoles was evaluated using a disk diffusion technique against both Gram-negative and Gram-positive bacteria.

Materials and methods: The study team utilized high-quality starting chemicals, solvents, and reagents with consistent chemical and physical properties. The Shimadzu IR-460 spectrometer was used in a KBr medium to get the Ft-IR spectra of the synthesized nanocatalyst. Furthermore, we employed a Bruker DRX-400 AVANCE spectrometer to acquire 1H-NMR and 13C-NMR spectra of the synthesized compounds. The spectrometer utilized in this investigation functions at a frequency of 400 MHz. The solvent employed for the spectra of produced compounds was CDCl3, with TMS serving as the internal standard. The mass spectra of the produced compounds, which have an ionization potential of 70 eV, were obtained using the Finnigan MAT 8430 spectrometer. Elements of produced compounds were subjected to elemental analysis using the Heraeus CHN-O-Rapid analyzer.

Results: This work investigated the three-component reaction involving ninhydrins 1, diamines 2, and electron-deficient acetylenic compounds 3 for the eco-friendly production of pyrroloimidazoles derivatives 4 in water-based solutions at normal temperature. The results indicated that these molecules displayed noteworthy efficacy, similar to that of conventional antioxidants. Also, the results indicated that the synthesized pyrroloimidazoles have bacteriostatic properties.

Conclusion: In summary, this study aimed to examine the environmentally friendly characteristics of ninhydrins, diamines, and electron-deficient acetylenic compounds when dissolved in water at normal room temperature. The research resulted in the successful production of new pyrroloimidazole derivatives with a high rate of success. This study conducted a more in-depth analysis of the antioxidant properties of the synthesized pyrroloimidazoles 4a-4d by the utilization of two techniques: DPPH radical scavenging and FRAP assays. The results indicated that these molecules displayed noteworthy efficacy, similar to that of conventional antioxidants. Furthermore, we utilized both Gram-positive and Gram-negative bacteria to showcase the antibacterial effectiveness of the synthesized pyrroloimidazoles by the disk diffusion technique. The results indicated that the synthesized pyrroloimidazoles have bacteriostatic properties. These reactions provide benefits, such as efficient utilization of atoms, generation of large quantities of products, and straightforwardness of the reaction.