Synthesis, characterization and antimicrobial activity of pyrazole derivatives

Abstract

This study synthesized pyrazole derivatives from pyrazoline and evaluated them for antibacterial activity. From benzofuran- 5-carbaldehyde and 1-(1,2,3,4-thiatriazol-5-yl)hydrazine, compound 1 is formed under reflux. Then DMF and POCl3 is added at 70°C for 5 h to the compound 1 to get compound 2. To a mixture of compound 2, acetophenone in ethanol and KOH is added and stirred under reflux for 6 h to get compound 3. From the compound 3, different pyrazole derivatives have been synthesized. All the desired compounds have been successfully synthesized and characterized by 1H and 13C NMR and LCMS. The antimicrobial activity has been tested using a serial dilution approach against several Gram-positive and Gram-negative bacteria. Compounds 1, 3, 5, 6, 8 and 9 show greater antimicrobial activity against several Gram-positive and Gram-negative bacteria.