A Unique Transformation of 5-Amino-N'-methoxyimidazole-4-carboxamidines by Diazotization: Synthesis of the 5-Azido Analogue of ACIA Riboside

Diazotization of 1-substituted 5-amino-N'-methoxyimidazole-4-carboxamidines (I) was found to give the 5-azidoimidazole-4-carbonitriles II through the 1-methoxy-2-azaadenine intermediates IV. The product IIb from the riboside Ib was utilized for the synthesis of 5-azido-1-β-D-ribofuranosylimidazole-4-carboxamide (Vb), a novel AICA riboside analogue