The esterification of 2-aminoisobutyric acid (I) with methanol - HCl gives the corresponding methyl ester (II), which is formylated with formic acid - acetic anhydride or methyl formate yielding the formamide (III). Dehydration of (III) with diphosgene (DPG) or POCl3 in pyridine affords methyl 2-isocyanoisobutyrate (CPI) (IV). Finally, this compound or its ZnBr2 complex [Zn(CPI)2Br2] is treated with 99mTcO4 and sodium dithionite or SnCl2 respectively, in ethanol-water solution. The radiochemical purity was >95%.