A simple and efficient synthesis of 9-substituted guanines. Cyclodesulfurization of 1-substituted 5-[(thiocarbamoyl) amino] imidazole-4-carboxamides under aqueous …

B Alhede, FP Clausen, J Juhl-Christensen…

Index: Alhede; Priess Clausen; Juhl-Christensen; McCluskey; Preikschat Journal of Organic Chemistry, 1991 , vol. 56, # 6 p. 2139 - 2143

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Citation Number: 44

Abstract

5-Aminoimidazole-4-carboxamide (AICA)(la) is 1-alkylated by an improved method. The resulting 5-amino-1-alkylimidazole-4-carboxamides (lb-i) are converted to the corresponding l-alkyl-5-[(thiocarbamoyl)-amino] imidazole4carboxamides (3). These compounds are ring closed under alkaline conditions to Ssubstituted guanines (5) in very high yields by treatment with heavy-metal salts in aqueous sodium hydroxide, or, in ...