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-5H-6, 7-dihydroimidazo [2, 1-c][1, 2, 4] triazole (4b) was obtained by the alkylation of the respective 7-(4-methylphenyl)-2, 5, ...