Synthesis of imidazoline and imidazo[2,1-c][1,2,4]triazole aryl derivatives containing the methylthio group as possible antibacterial agents

Abstract 1-Arylimidazolidine-2-thiones ( 1a – g ) were synthesized by the condensation reaction of N -arylethylenediamines with carbon disulfide in xylene medium. Their further alkylation with methyl iodide led to the formation of some biologically active 1-aryl-2-methylthio-imidazolines ( 2a – g ). The 7-(4-methylphenyl)-3-methylthio-5 H -6,7-dihydroimidazo[2,1- c ][1,2,4]triazole ( 4b ) was obtained by the alkylation of the respective 7-(4-methylphenyl)-2,5,6,7-tetrahydroimidazo[2,1- c ][1,2,4]triazol-3( H )-thione ( 3b ) with methyl iodide. Antimicrobial activities of 1-aryl-2-methylthio-imidazolines ( 2a – g ) and the 7-(4-methylphenyl)-3- methylthio-5 H -6,7-dihydroimidazo[2,1- c ][1,2,4]triazole ( 4b ) are presented. All tested compounds showed MIC in the range of 11.0–89.2 μM. Compounds 2a , e were found to be equipotent to chloramphenicol in vitro, whereas 2a , c , e – g and 4b showed superior activity (MIC) to ampicillin.