Synthesis, characterization, antimicrobial, antioxidant, and molecular docking study of 3-(2,5-dichlorothiophen-3-yl)-5-arylpyrazole-1-carbothioamides and their thiazole derivatives

In the present study, a new series of 3-(2,5-dichlorothiophen-3-yl)-5-aryl-4,5-dihydro-1H-pyrazole-1-carbothioamides 2 were synthesized either by the reaction of (E)-3-aryl-1-(2,5-dichlorothiophen-3-yl)prop-2-en-1-ones 1 with thiosemicarbazide or by one-pot reaction of 3-acetyl-2,5-dichlorothiophene with the corresponding aldehyde and thiosemicarbazide. Additionally, 2-(3-(2,5-dichlorothiophen-3-yl)-5-aryl-4,5-dihydro-1H-pyrazol-1-yl)-4-phenylthiazoles 3 were synthesized in 46-89% yields by the reflux of carbothioamides 2 with 2-bromoacetophenone. The structures of the newly synthesized compounds were characterized by IR, H-1-NMR, C-13-NMR, DEPT-135, and mass spectrometry analysis (MS). All new compounds were evaluated as antimicrobial and antioxidants. Compound (3b) exhibited moderate activity against Bacillus subtilis and Penicillium fimorum, 14 +/- 0.5 mm and 18 +/- 0.75 mm, respectively, while the other synthesized compounds did not show activity against the tested microbes. The most potent antioxidant activity showed by compound (2a) and (2e) with 95.2% and 96.3%, which considered good to excellent antioxidant activity compared with the control (ascorbic acid) and other synthesized compounds. Molecular docking study of the new compounds with cytochrome P450 14 alpha-sterol demethylase (CYP51) was carried out to evaluate their possibility as drugs and to implement structural improvements for this purpose. All synthesized compounds exhibited good affinity with (CYP51), notably, (3a) and (3b) compounds showed the highest affinity with the lowest binding energies. [GRAPHICS] .