Microwave Assisted Synthesis, Characterization and Evaluation for Antimicrobial Activity of Novel 1, 5-Benzothiazepines

Aims: 1,5-benzothiazepine ring is privileged aromatic heterocycles of interest to organic and medicinal chemists because of its ease of synthesis and biological activities. This study aims to synthesize new series of 1, 5-benzothiazepine by direct and efficient microwave assistance and to evaluate for antimicrobial activity by MIC method. Place and Duration of Study: The study was conducted at Department of Pharmaceutical Chemistry, Chebrolu Hanumaiah Institute of Pharmaceutical Sciences, Guntur-19, A. P. from January, 2019 to October, 2021. Methodology: 1, 5-benzothiazepines (BT-21 to BT-40) were synthesized by microwave irradiation. The structures of the products were established by elemental analysis, FTIR, 1H-NMR, 13C-NMR and mass spectroscopic studies. The synthesized compounds were also evaluated for their Antimicrobial activity by MIC method. Results: The microwave assisted synthetic procedure adopted yielded the 1,5-benzothiazepine derivatives BT-21 to BT-40 in good amounts and at a lesser time span. The synthesized 1, 5-benzothiazepine derivatives showed good to moderate antibacterial and antifungal activities.BT-25 having a dihydroxy-methyl-phenyl moiety proved to be more potent against all selected bacterial strains, B. subtilis, S. aureus, E. coli and P. aeruginosa with a MIC value of 64 µg/ml. BT-33 having fluorophenyl moiety, BT-35 having hydroxyl-nitrophenyl moiety and BT-40having dibromophenyl moiety proved to be more potent against all selected fungal strains, A. niger and C. tropicalis with a MIC value of 16 µg/ml. Conclusion: These results showed that the synthesized 1, 5-benzothiazepine derivatives have better scope for further development as antimicrobial agents.