engleski

Microwave - assisted quaternization of various pyridine derivatives and their antibacterial activity

Numerous pyridinium derivatives have been investigated concerning their biological and pharmacological activities. Their importance lies in their effective antimicrobial, antiviral, antihypertensive and immunostimulating activities. Some of pyridinium aldo xime derivatives are potential antidotes against organophosphate poisoning. In this study, reactions of quaternization under microwave heating of pyridine, α - picoline, pyridine-4-aldoxyime, pyridine-2- aldoxime, nicotinamide, isonicotinamide and pyridoxal oxime with different electrophiles: 2-bromo-4'-nitroacetophenone, 2-amino-4-chloromethylthiazole hydrochloride, methyl iodide, 1, 3-diiodopropane and 1, 3-dibromopropane are reported. The synthesis yield by microwave dielectric heating is improved and reaction time shortened compared to conventional heating. Some of the synthesized compounds were tested regarding their potential antibacterial activity against two Gram-positive and two Gram-negative bacteria. Antibacterial assessment showed a relatively high efficacy of 1-[2-(4-nitrophenyl)-2-oxoethyl]pyridinium bromide against G-positive and G-negative bacteria.

pyridine, pyridine derivates, quaternization, quaternary pyridinium salts, microwave sythesis

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