2-Amino-1-methyl-1H-imidazole-4,5-dione: Synthesis and the Dimroth Type Rearrangement to Creatone (2-Methyl-amino-1H-imidazole-4,5-dione)

Abstract Treatment of creatinine with BOC-ON gave 2-t-butoxycarbonylamino-1-methyl-1,5-dihydro-4H-imidazol-4-one, which was oxidized with mercury(II) acetate to the corresponding 1H-imidazole-4,5-dione. Deprotection of the amino group of this dione afforded the title compound 4, which in turn was shown to undergo a facile, Dimroth-type rearrangement under weakly acidic conditions to give creatone, thus proving 4 to be the key intermediate in the formation of creatone from various starting materials. The equilibria among these compounds are discussed.