An Eco-Friendly Ultrasound-Assisted Synthesis of Novel Fluorinated Pyridinium Salts-Based Hydrazones and Antimicrobial and Antitumor Screening

Abstract

The present work reports an efficient synthesis of fluorinated pyridinium salts-based hydrazones under both conventional and eco-friendly ultrasound procedures. The synthetic approach first involves the preparation of halogenated pyridinium salts through the condensation of isonicotinic acid hydrazide (1) with p-fluorobenzaldehyde (2) followed by the nucleophilic alkylation of the resulting N-(4-fluorobenzylidene)isonicotinohydrazide (3) with a different alkyl iodide. The iodide counteranion of 5–10 was subjected to an anion exchange metathesis reaction in the presence of an excess of the appropriate metal salts to afford a new series of fluorinated pyridinium salts tethering a hydrazone linkage 11–40. Ultrasound irradiation led to higher yields in considerably less time than the conventional methods. The newly synthesized ILs were well-characterized with FT-IR, 1H NMR, 13C NMR, 11B, 19F, 31P and mass spectral analyses. The ILs were also screened for their antimicrobial and antitumor activities. Within the series, the salts tethering fluorinated counter anions 11–13, 21–23, 31–33 and 36–38 were found to be more potent against all bacterial and fungal strains at MIC 4–8 µg/mL. The in vitro antiproliferative activity was also investigated against four tumor cell lines (human ductal breast epithelial tumor T47D, human breast adenocarcinoma MCF-7, human epithelial carcinoma HeLa and human epithelial colorectal adenocarcinoma Caco-2) using the MTT assay, which revealed that promising antitumor activity was exhibited by compounds 5, 12 and 14.

Novel amphiphilic pyridinium ionic liquids-supported Schiff bases: ultrasound assisted synthesis, molecular docking and anticancer evaluation

“…More specifically, pyridinium salts carrying long alkyl chains were found to be outstanding bioactive agents as antimicrobial [13], anticancer [14] and biodegradable [15] agents. Recently, we have reported a green ultrasound synthesis of novel fluorinated pyridinium hydrazones using a series of alkyl halides ranging from C2 to C7 [16]. The biological screening results revealed that the activity increased with increasing the length of the alkyl side chains, especially for hydrazones tethering fluorinated counteranions (PF 6 − , BF 4 − and CF 3 COO − ).…”

New 1,2,3-Triazole Scaffold Schiff Bases as Potential Anti-COVID-19: Design, Synthesis, DFT-Molecular Docking, and Cytotoxicity Aspects

“…The resulting 1,2,3-triazoles bearing bis-Schiff base moieties 5a – g were prepared in 87–90% yields. The 1 H-NMR spectra of similar reported compounds showed the existence of E/Zgeometrical isomers in the imine (CH=N) bond and cis/trans conformers in the amide (C=O and N–H) group [ 30 , 31 , 32 ] ( Scheme 2 ).…”

Ecofriendly microwave-assisted preparation, characterization and antitumor activity of some propylimidazolium-based Ionic liquids derivatives

“…Based on interesting results published recently, we focused on the preparation of a new family of RTILs (1-20) by using microwave irradiation and conventional procedure in order to test them for antitumor activities [37][38][39]. As shown in Scheme 1, 1propylimidazolium-based ionic liquids (1-5) have been synthesized through the reaction of 1-propylimidazole in toluene with a suitable alkyl bromide at 80°C for 18 h. The quaternization reaction was performed via the nucleophilic attack of the Sp 2 -N imidazole atom on the alkyl bromide in order to produce the desired imidazolium bromides (1-5).…”