Improved synthesis of the hypoxia probe 5-deutero-5-fluoro-5-deoxy-azomycin arabinoside (FAZA) as a model process for tritium radiolabeling

Tritium-labelled fluoroazomycin arabinoside, [3H]-FAZA, is a useful probe for the investigation of hypoxia, furthermore it is safer and easier to handle than the PET tracer [18F]-FAZA when used in cell based assays. The only known synthesis of deuterium- and tritium-labelled FAZA was re-investigated and optimized. Then, a new and improved synthesis of [2H]-FAZA was developed as a model process for tritium radiolabelling. This novel synthesis is expected to greatly facilitate access to [3H]-FAZA.