An improved synthesis of alpha-AZA, alpha-AZP and alpha-AZG, the precursors to clinical markers of tissue hypoxia

alpha-[I-123]-IAZA and alpha-[I-123]-IAZP are experimental diagnostic radio pharmaceuticals which have been used clinically to diagnose hypoxia in a nu mber of pathologies, including cancer, peripheral vascular disease, rheumat oid arthritis and brain trauma. These nitroimidazole nucleosides are synthe sized from the non-iodinated nucleosides AZA, AZP and AZG, respectively. Ea rlier methods report low chemical yields for the synthesis of these precurs ors. The modified procedures now reported provide nearly quantitative yield s of these compounds, thereby substantially reducing the cost and effort of synthesis. (C) 2001 Elsevier Science Ltd. All rights reserved.