5971. Methimazole

Nomenclature

CAS number: 60-56-0
1,3-Dihydro-1-methyl-2H-imidazole-2-thione; 1-methylimidazole-2-thiol; 1-methyl-2-mercaptoimidazole; mercazolyl; thiamazole; Danantizol (Gador); Favistan (Temmler); Mercazole (Chugai); Strumazol (Nycomed); Tapazol (Lilly); Tapazole (King); Thacapzol (Recip); Thyrozol (Merck KGaA); Tirodril (Estedi); Tizorol (Rudefsa).
C4H6N2S; mol wt 114.17.
C 42.08%, H 5.30%, N 24.54%, S 28.09%.

Description and references

Antihormone; inhibits iodide integration into tyrosyl residues, inhibiting production of thyroid hormones. Prepd by treating aminoacetaldehyde diethyl acetal with methyl isothiocyanate: Wohl, Marckwald, Ber. 22, 1354 (1889); from thiocyanic acid and N-substituted amino acetals: R. G. Jones et al., J. Am. Chem. Soc. 71, 4000 (1949). NMR structural study: M. Garner et al., Bioorg. Med. Chem. Lett. 4, 1357 (1994). HPLC determn in fish homogenates: L. Hollosi et al., J. Pharm. Biomed. Anal. 36, 921 (2004). Metabolism: D. S. Sitar, D. P. Thornhill, J. Pharmacol. Exp. Ther. 184, 432 (1973). Comprehensive description: H. Y. Aboul-Enein, A. A. Al-Badr, Anal. Profiles Drug Subs. 8, 351-370 (1979). Review of pharmacology and clinical experience: D. S. Cooper, N. Engl. J. Med. 311, 1353-1362 (1984). Use in feline hyperthyroidism: G. Hoffmann et al., J. Feline Med. Surg. 5, 77 (2003). Clinical trial in hyperthyroidism: F. Azizi et al., Eur. J. Endocrinol. 152, 695 (2005).

Chemical structure

Properties

White to pale buff, crystalline powder; faint characteristic odor. Leaflets from alc, mp 146-148°. bp 280° (some decompn). uv max (0.1N H2SO4): 211, 251.5 nm (E1%1cm 593, 1528). Freely sol in water. Sol in alcohol, chloroform. Sparingly sol in ether, petr ether, benzene.

Use

In cyanide-free silver electroplating. Model compound for endocrine disruption in physiological studies.

Therapeutic Category

Antihyperthyroid.

Therapeutic Category (Veterinary)

In treatment of feline hyperthyroidism.

Keywords

Antihyperthyroid