Synthesis of some new antipyrine-thiophene hybrids and their evaluations as antioxidant and antibacterial agents

ABSTRACT. A novel series of antipyrinyl thienyl ketones 4a-c, 7a-c, 10a-c, and 13a-b was chemically synthesized through the cyclocondensation 4-chloroacetylantipyrine with various 2-substituted-thioacetanilide scaffolds, including 3-arylazo-4-mercapto-4-phenylamino-buten-2-ones, ethyl 2-arylazo-3-mercapto-3-phenylamino-acrylate, 2-cyano-3-mercapto-3-(phenylamino)-N-arylacrylamide, 4-mercapto-4-(phenylamino)but-3-en-2-one, and/or ethyl-3-mercapto-3-(phenylamino)acrylate. Indeed, reaction 4-hydroxybenzaldehyde followed by refluxing 2-cyanoacetohydrazide yielded 2-cyano-N'-(4-(2-(antipyrin-4-yl)-2-oxoethoxy)benzylidene)-acetohydrazide 17 as a building compound, which used consequentially to synthesize set new hybrids 19a-d. The chemical structures newly synthesised compounds were unambiguously confirmed using extensive elemental spectral data analyses. screened for their antioxidant antimicrobial activities. Compared test reference (Ascorbic acid, 88.0%), 13a 13b substituted methyl hydroxyl groups at thiophene ring system displayed excellent properties, 87.8% 87.2%, respectively. Additionally, showed high antibacterial activities, relative activity index (which ranges from 68% 91.7%) close that Ampicillin.
 
 KEY WORDS: 4-Chloroacetylantipyrine, Thioacetanilide, Antipyrinyl ketones, Antioxidant, Antimicrobial
 Bull. Chem. Soc. Ethiop. 2023, 37(1), 123-140. a
 DOI:https://dx.doi.org/10.4314/bcse.v37i1.11