Synthesis and Structure Elucidation of 4-(4-Amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3yl-methylene)-2-phenyl-1H-imidazol-5(4H)-one

4-(4-Amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl-methylen)2-phenyl-1(3H)-imidazol-5-one (5) was synthesized in four steps in high yield. Benzimidinium chloride (1) reacted with dimethyl acetylenedicarboxylate to afford 2-phenyl-4-methoxycarbonylmethylen-1(3H)-imidazol-5-one (2) which was converted to 2-phenyl-4-hydrazinecarbonylmethylen-1(3H)-imidazol-5-one( 3) using hydrazine hydrate in methanol. Furthermore, the reaction of (3) with carbon disulfide afforded compound (4) which can be used without further purification to achieve compound (5) using hydrazine hydrate.