Purines, pyrimidines, and imidazoles. Part XXXVI. Carboxylation of some 5-aminoimidazoles and related compounds, including nucleosides and nucleotides, with potassium hydrogen carbonate in aqueous solution

Abstract

5-Aminoimidazole and some 1-substituted derivatives, including the naturally occurring riboside and ribotide, have been shown to form the corresponding 5-aminoimidazole-4-carboxylic acids in 40–50% yields when heated with aqueous potassium hydrogen carbonate. Similar reactions occur with unsubstituted and 1-substituted 5-amino-pyrazoles and, to a lesser extent, with 5-amino-1,2,3-triazole. In addition to the 5-amino-azole-4-carboxylic acids, the reaction mixtures contained unchanged 5-amino-azoles. Similar mixtures of 5-amino-azole and 5-amino-azole-4-carboxylic acid were obtained when several 5-amino-imidazole, -pyrazole, and -1,2,3-triazole-4-carboxylic acids were heated with aqueous potassium hydrogen carbonate.