Synthesis, characterization and antimicrobial evaluation of novel urea, sulfonamide and acetamide 3,4-dihydropyrazino[1,2-a]indol-1(2H)-one derivatives

Abstract Series novel of 2-(substituted)-3,4-dihydropyrazino[1,2- a ]indol-1(2 H )-one (4a – e) and its urea (7a – f) , sulfonamide (9a – d) and acetamide (12a – d) derivatives were synthesized and were characterized by 1 H NMR, 13 C NMR and LC–MS analysis and were screened for their antimicrobial activities. The newly synthesized compounds were characterized by 1 H NMR, 13 C NMR and LC–MS analysis. All compounds were evaluated for in vitro antibacterial activities against Escherichia coli (MTCC 443), Pseudomonas aeruginosa (MTCC 1688), Staphylococcus aureus (MTCC 96) and Streptococcus pyogenes (MTCC 442) strains and in vitro antifungal activities against Candida albicans (MTCC 227), Aspergillus niger (MTCC 282) and Aspergillus clavatus (MTCC 1323) strains by using serial broth dilution method. These compounds showed good antimicrobial activities against above bacterial species.