Compounds in which at least one atom in the ring is nitrogen are defined as azoles. Imidazoles constitute an important class of azole compounds. Many compounds found in nature contain an imidazole ring in their structure. Imidazole and its derivatives are biologically active compounds. These compounds are widely used as antifungal, antimicrobial and anticancer agents.  There are many compounds containing the imidazole ring that are used as drugs. One of the most important imidazole derivatives used as a drug is 2-mercapto-1-methylimidazole. 2-Mercapto-1-methyl-imidazole, also known as methimazole or thiamazole, is an important compound with the molecular formula C₄H₆N₂S. This compound has been known since 1889 and has been used as an antithyroid drug since 1945. It is the most widely used antithyroid drug in the world because the effect of the compound is maximum and its side effects are minimum. Methimazole can form complexes of different structures with salts of metals such as platinum, silver and ruthenium. These complexes show different physical and chemical properties.