Synthesis and Antimicrobial Activity of Some Novel Quinoline, Chromene, Pyrazole Derivatives Bearing Triazolopyrimidine Moiety

Abstract

7‐Amino‐3‐phenyl‐[1,2,4]triazolo [4,3‐a] pyrimidin‐5(1H)‐one (5) was utilized as key intermediate for the synthesis of some new, quinolines 9, 10, 11, 12, 13, 14 and 18, 19, 20, acrylonitrile 25 and 28, coumarin 26, and pyrazoles 31, 32, 33, 34 incorporating triazolopyrimidines. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, 1H NMR, and mass spectral data. Representative compounds of the synthesized products were tested and evaluated as antimicrobial. Compounds 25, 28, 31, 32, 33, and 34 are the most promising.

Synthesis of 1,2,4‐triazolopyridazines, isoxazolofuropyridazines, and tetrazolopyridazines as antimicrobial agents

“…[4,30,31,35,37] In this manuscript and previous articles generally, the bacteria and fungi types are influenced through this category of heterocyclic compounds. [30,31,35,37] Moreover, past results and our findings in this article corroborate the promising antimicrobial activity of 1,2,4-triazolopyridazine, isoxazolofuropyridazine, tetrazolopyridazine, and piperazinyl or morpholinyl-pyridazine derivatives which can be developed to the highest antimicrobial activities.…”

“…In the study of the relationship among chemical structures and microbial activity (Structure-activity relationships [SARs]) of the synthesized compounds, the next conclusion was obtained, first maybe: very good antimicrobial activity were found to compounds; 1,2,4-triazolopyridazine (16a,b), isoxazolo-furo-pyridazine (10a-c), tetrazolo-pyridazine (12), piperazinyl or morpholinylpyridazine (14a,b) derivatives against the test microorganisms, because they contain 1,2,4-triazole ring as an essential nucleus with an increasing number of nitrogen atoms according to past and new scientific articles. [30,31] Second, maybe the same compounds 16a, b, 10a-c, 12, and 14a-b possess highest antimicrobial activities because of the transformation of the (NH-NH 2 ) group into 1,2,4-triazole ring linkage with numerous functional groups and other of rings such as isoxazole, tetrazole, and furo-pyridazine. Hence, pyridazine link with many functional groups such as pyridine, phenyl, methoxy, methyl, ethyl, hydroxy, chloro, triazole, isoxazole, tetrazole, and quinazolinone moieties.…”

“…The newly prepared compounds were dissolved in dimethyl sulfoxide (DMSO) and tested for their antimicrobial activity by the agar disk diffusion technique. Cefotaxime sodium and nystatin [30][31]35,37] were used as the standard drugs for antibacterial and antifungal assays, respectively. A solution of 100 μg mL −1 of the tested compound was practical and microplate wells, 1 cm in diameter, were used.…”

“…Compound-impregnated disks were placed on an agar plate containing a standard suspension of microorganisms. The plate was incubated for 24 hours at 37 C. For the assessment of the minimum inhibitory concentration (MIC) by the serial plate dilution way, [30][31]35,37] 5 mg of each tested compound was dissolved in 1 mL of DMSO separately to prepare stock solutions. Serial dilutions were prepared from each stock solution.…”

“…Our research group has published a lot of scientific research that include many biological and pharmaceutical activities. [18,[30][31][32][33][34][35][36][37][38] Furthermore, with the continuation of the research work in this manuscript, we have prepared many of heterocyclic compounds such as furopyridazinones, isoxazolopyridazines, tetrazolopyridazines, pyridazinoquinazolinones, piperazinyl and morpholinopyridazines, hydrazinylpyridazines, and 1,2,4-triazolopyridazines with studying their activities as antimicrobials in vitro.…”