  Efficient syntheses of some new substituted pyrazoline derivatives linked to
substituted benzimidazole scaffold were performed by multistep reaction
sequences. All the synthesized compounds were characterized using elemental
analysis and spectral studies (IR, 1D/2D NMR techniques and mass spectrometry).
The synthesized compounds were screened for their antimicrobial activity
against selected Gram-positive and Gram-negative bacteria, and fungi strain.
The compounds with halo substituted phenyl group at C5 of the 1-phenyl
pyrazoline ring (15, 16 and 17) showed significant antibacterial activity.
Among the screened compounds, 17 showed most potent inhibitory activity (MIC =
64 {\mu}g mL-1) against a bacterial strain. The tested compounds werefound to
be almost inactive against the fungal strain C. albicans, apart from
pyrazoline-1-carbothiomide 21, which was moderately active.
