Design, synthesis and biological evaluation of some novel N'-(1,3-benzothiazol-2-yl)-arylamide derivatives as antibacterial agents

In the present work, we carried out hydroxybenzotriazole (HOBT) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCl)-mediated synthesis of new N'-(1,3-benzothiazol-2-yl)-arylamides C1-18 in high yields under relatively milder reaction conditions using dimethyl formamide as solvent. Synthesized compounds were characterized by FTIR, 1H-NMR, 13C-NMR and HRMS spectral data. The MIC values of synthesized compounds C1-18 were determined by the broth microdilution method using Mueller Hinton medium. Tested compounds showed variable activity against the tested Gram-positive and Gram-negative bacterial strains. Compounds C3, C5, C9, C13-15 and C17 exhibited promising activity against Staphylococcus aureus NCIM 5021 with MIC values in the range of 19.7–24.2 μM. Among all tested compounds, C13 possessing thiophene ring attached to the benzothiazole moiety via amide linkage exhibited maximum activity against S. aureus NCIM 5022 with MIC of 13.0 μM. Compound C13 showed maximum activity against S. aureus ATCC 43300 with MIC of 15.0 μM and exhibited bactericidal activity against this strain in minimum bactericidal concentration determination. This compound also eliminated S. aureus ATCC 43300 strain after 24-h exposure indicating its bactericidal activity. ADMET calculation showed favourable pharmacokinetic profile of synthesized compounds C1-18.