Synthetic Utility of Pyridinium Bromide: Synthesis and Antimicrobial Activity of Novel 2,4,6‐Trisubstituted Pyridines Having Pyrazole Moiety

Abstract

Fourteen potentially bioactive pyridines, pendant to pyrazole moiety, were synthesized and evaluated in vitro for their antimicrobial potential. Treatment of 2‐bromo‐1‐(5‐methyl‐1‐phenyl‐1H‐pyrazol‐4‐yl)ethanone with pyridine afforded the corresponding pyridinium bromide salt. Reaction of the latter salt with α,β‐unsaturated ketones yielded the corresponding 2,4,6‐trisubstituted pyridine derivatives. The structures of the synthesized products were confirmed by all possible spectral data. The antimicrobial activity of some selected products was evaluated by using well‐diffusion agar assay and minimum inhibitory concentration determination, and the results revealed good‐to‐moderate activities compared with reference drugs.

Design, Synthesis, and Structural Elucidation of New Pyridine and Thienopyridine Derivatives

“…Thienopyridines are considered as a class of the most important fused pyridines that reported as drugs, for example, Prasugrel , ticlopidine, and clopidogrel , in addition to irreversible ADP receptor/P2Y12 inhibitors that were used as an antiplatelet agent . Thienopyridines are reported as anticancer , antibacterial , antifungal , anti‐inflammatory , and antimicrobial agents . In view of these findings and in continuation of our previous work on pyridine and thienopyridine chemistry , we report herein facial synthetic approaches for new series of substituted and condensed pyridines.…”

The Chemistry of Acetylpyrazoles and Its Utility in Heterocyclic Synthesis

“…Thus, treatment of the bromide salt 165 with benzalacetophenone 166a in acetic acid in the presence of ammonium acetate at reflux condition resulted in the formation of the novel 2‐(5‐methyl‐1‐phenyl‐1 H ‐pyrazol‐4‐yl)‐4,6‐diphenylpyridine ( 167 ) in 78% yield (Scheme ). In a similar way, the bromide salt 165 reacted with several chalcones 166b–n under similar experimental reaction condition to afford the corresponding 2,4,6‐trisubstituted pyridines 167b–n , as illustrated in Scheme .…”

Pyridine Derivatives as Biologically Active Precursors; Organics and Selected Coordination Complexes

“…The active derivatives bear Cl À and F À in addition to aromatic substituents. [50] Compounds containing py as a substituent are accessible in laboratory with excellent yield but the antimicrobial efficiency needs further improvement. [51] From the list of compounds provided in Figure 5 with summarized activity against certain strains in Table 2, it can be observed that these compounds have extra potentials to emerge as antimicrobial agents in future.…”