Synthesis and Antimicrobial Screening of 3-Fluoromethyl Pyrazole Derivatives

Abstract

A new series of 1-(5-(4-alkoxy-3-(methylsulfonyl)phenyl)thiophen-2-yl)-5-substituted-3-(trifluoromethyl)-1H-pyrazole have been synthesized by a cyclocondensation reaction of 1,1,1-trifluoropentane-2,4-dione (1a) with (5-(4-methoxy-3-(methylsulfonyl)phenyl)thiophen-2-yl)hydrazine (2). The structure of 1-(5-(4-alkoxy-3-(methylsulfonyl)phenyl)thiophen-2-yl)-5-substituted-3-(trifluoromethyl)-1H-pyrazole derivatives was characterized by spectroscopic analysis. The synthesized 3-(trifluoromethyl)-1H-pyrazole derivatives were screened for in vitro antibacterial activity against Escherichia coli (NCIM 2574), Proteus mirabilis (NCIM 2388) Bacillus subtilis (NCIM 2063) and Staphylococcus albus (NCIM 2178) and in vitro antifungal activity against Candida albicans (NCIM 3100) and Aspergillus niger (ATCC 504). The compounds 4-(5-(5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl)thiophen-2-yl)-2-(methylsulfonyl)phenol (4) and 1-methyl-4-(4-(5-(5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl)thiophen-2-yl)-2-(methylsulfonyl)phenoxy)pyrrolidin-2-one (6e) showed moderate to good antibacterial and antifungal activity.