Synthesis, computational and antimicrobial evaluation of some new pyridine derivatives

A series of pyridine compounds were prepared by using 3-(dimethylamino)-1-(pyridin-4-yl)prop-2-en-1-one (14) as a precursor. The reaction of 14 with different reagents afforded different new heterocyclic compounds. All the new compounds were characterized by spectroscopic analyses. Moreover, the density function theory study was made to establish the geometry of the tested compounds. The antimicrobial activities of the newly prepared pyridine derivatives were studied against Gram-positive bacteria (Bacillus subtilis and Bacillus thuringiensis) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and fungi (Fusarium oxysporum and Botrytis fabae) by the minimal inhibitory concentration method. Compounds belonging to the pyran 32, pyridine 33, indenopyran 34, thiazolopyridine 35, and chromene 39 series displayed a high antimicrobial activity. It was found that the experimental results of the biological evaluation were in agreement with the molecular modeling studies.

Synthesis and anticonvulsant activity of 6-methyl-2-((2-oxo-2-arylethyl)thio)pyrimidin-4(3 H)-one derivatives and products of their cyclization

The alkylation of 6-methyl-2-thioxo-2,3-dihydro-1H-pyrimidine-4-one phenacyl bromides under different conditions was investigated. It was found that during the reaction in the medium of DMF/K2CO3 a mixture of 2-(2-aryl-2-oxoethyl)thio-6-methyl-pyrimidine-4(3H)-one and 3-hydroxy-3-aryl-7-methyl-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-5-one was formed. The holding of the resulting mixture in the concentrated sulphuric acid leads to the formation of cyclization products - derivatives of 3-aryl-7-methyl-5H-thiazolo[3,2-a]pyrimidin-5-one with high yields. Individual S-alkylated derivatives – 2-(2-aryl-2-oxoethyl)thio-6-methyl-pyrimidine-4(3H)-one - were obtained by reacting in methanol in the presence of sodium methoxide. Pharmacological screening of synthesized compounds for anticonvulsant activity on the model of pentylenetetrazole seizures in rats was carried out and some regularity “structure-activity” was established.