Synthesis and Antimicrobial Evaluation of Pyrazo-thiazoles

In an attempt to find a new class of antimicrobial agents, a series of novel pyrazol-1-yl-4-substitutedthiazole 4 (a-j) were synthesized. The 1,3-diphenylprop-2-en-1-one (1) was treated with thiosemicarbazide to obtain 3,5-diphenyl- 4,5-dihydro-1H-pyrazole-1-carbothioamide (2), which was then reacted with substituted phenacyl bromides in ethanol to obtain final compound 2-(3,5-diphenyl-4,5-dihydro-1H-pyrazol-1-yl)-4-substitutedthiazoles 4 (a-j). The synthesized compounds were confirmed by melting point, IR, 1H-NMR, 13C NMR and Mass spectroscopy. All the synthesized compounds were screened for antimicrobial activity among the tested series, 4c exhibited significant antibacterial activity against gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and 4d against gram negative E.coli. Similarly 4c and 4d showed significant antifungal activity (31.25 μg/mL) when compared to fluconazole against C. albicans