In search of benzamidoxime (BHam) derivatives that provide a single 99m Tc-labeled compound of high in vivo stability, we synthesized three N-alkyl compounds of benzamidoxime (BHam) ligand. They provided a single 99m Tc-labeled compound by ligand exchange reaction of 99m Tc-glucoheptonate in high radiochemical yields (over 95% at MBHam concentration of 1 × 10 −5 M). 99m Tc-N-methyl benzamidoxime ( 99m Tc-MBHam) showed higher stability than ...