Improved synthesis of [¹¹C]methylaminobenzovesamicol

An efficient two‐step synthesis of the potential cholinergic neuronal mapping tracer [ 11 C]methylaminobenzovesamicol (MABV) is described. A tert ‐butoxycarbonyl protecting group was used to activate the aniline nitrogen of aminobenzovesamicol toward [ 11 C]methyl iodide methylation under basic conditions. Following labeling, the protecting group was removed by brief acid treatment and the final product was purified by normal phase HPLC. The decay corrected yields of MABV are in the range of 30‐70 %, based on 11 CO 2 , with a specific activity of 0.5‐1.5 Ci/ μmol and synthesis time of less than 45 minutes. This new route makes clinical scale doses of this interesting compound available for human positron emission tomography studies.