A new hybrid approach and in vitro antimicrobial evaluation of novel 4(3H)-quinazolinones and thiazolidinone motifs

•The design and synthesis of the fluorine-containing hybrid system of quinazolinone and thiazolidinone was accomplished.•Newly synthesized compounds exhibited potential antimicrobial activity.•The assumed structures of the target molecules were confirmed by IR, NMR and mass spectral techniques.•Introduction of fluorine atom increases antimicrobial activity.

We have synthesized some novel fluorine containing 5-arylidene derivatives bearing different pharmacophores and heterocyclic systems like quinazolinone along with 4-thiazolidinone, which may act as potential antimicrobial agents. They have been synthesized by the Knoevenagel condensation of N-(2-(4-fluorophenyl)-4-oxothiazolidin-3-yl)-4-(4-oxo-2-p-tolylquinazolin-3(4H)-yl)benzamide with aromatic aldehydes to form N-(5-(aryl)-2-(4-fluorophenyl)-4-oxothiazolidin-3-yl)-4-(4-oxo-2-p-tolylquinazolin-3(4H)-yl)benzamides (6a–t). The products were characterized by IR, 1H, 13C and 19F NMR and mass spectral techniques. The synthesized compounds were evaluated for their in vitro antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus and Streptococcus pyogenes), Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and fungi (Candida albicans, Aspergillus niger, and Aspergillus clavatus) using serial broth dilution method. Compounds 6b, 6d, 6i, 6j, 6k, 6n and 6s were the most noteworthy derivatives identified in the present study because of their remarkable in vitro antimicrobial potency.

Graphical abstractA new synthesis and in vitro antimicrobial evaluation of novel fluorine containing 4(3H)-quinazolinone and thiazolidinone motifs were carried out. Incorporating a fluorine atom to 4-thiazolidinone skeleton resulted in better antimicrobial activities than our previously reported compounds. Compounds 6b, 6d, 6i, 6j, 6k, 6n and 6s were the most noteworthy derivatives identified in present study because of their remarkable in vitro antimicrobial potency.Figure optionsDownload full-size imageDownload as PowerPoint slide