Convenient synthesis and biological activities of pyridine derivatives of 3,4-dihydropyrimidin-2(1H)-ones

Synthesis, Antimicrobial, Antiquorum-Sensing, and Cytotoxic Activities of New Series of Isoindoline-1,3-dione, Pyrazolo[5,1-a]isoindole, and Pyridine Derivatives

New series of isoindoline-1,3-diones 2-9, pyrazolo[5,1-a]isoindoles 10-14, and pyridines 16-18 were synthesized. Twenty of the synthesized compounds were screened for their antibacterial activity against S. aureus, B. cereus, and E. coli. Compound 5 was proved to be the most active member in this study, showing the highest antibacterial activity against the three selected microorganisms. The antifungal activity of these compounds was also tested against C. albicans and A. flavus 3375. Compounds 4, 5, 8, and 17a exhibited the best antifungal activity against A. flavus 3375. The same compounds were examined for their antiquorum-sensing activity against Ch. violacium ATCC 12472, whereas compound 5 displayed strong antiquorum-sensing activity. The in vitro cytotoxicity testing of compounds 4-9 and 17a against human normal lung fibroblast (W138) cell line revealed that compounds 4, 5, and 8 are the least cytotoxic analogs in this study. In vivo acute toxicity testing of compounds 4, 5, and 8 was performed. The DNA-binding affinity of compounds 4-9 and 17a was also tested and the obtained results showed that all tested compounds have moderate DNA-binding affinity.

A Simple and Efficient One-pot Synthesis of 4-alkyl-3,4-dihydropyrimidin-2(1H)-ones

4-Alkyl-3,4-dihydropyrimidin-2(1 H)-ones possess a number of important properties in comparison with their 4-aryl analogues. We show that these compounds can be synthesised by a simple one-pot reaction of urea or thiourea, different aliphatic aldehydes (from acetaldehyde to valeraldehyde) and various dicarbonyl compounds (ethyl acetoac-etate, pentane-2,4-dione, N-(4-chlorophenyl)-3-oxobutanamide, acetoacetaldehyde dimethylacetal) in refluxing DMF or HOAc without use of any catalyst. The methylation of 4-alkyl-5-C(O)R-3,4-dihydropyrimidin-2(1 H)-ones leads to 1-methyl derivatives.