The designedphotolabelingprobes: 5-diazonium-1-β-D-ribofuranosyl-1H-imidazole-4-carboxamide (1) and 5-azido-1-β-D-ribofuranosyl-1H-imidazole-4-carboxamide (2) were synthesized via a short and convenient synthetic route,namely by diazotizing AICAR and subsequently performing substitution with NaN 3 . Although 1 was not stable even at low temperatures, 2 showed a rapid and clean photochemical reaction