SYNTHESIS OF 1]METHYLAMINO(PHENYL)BUTYRYL]-L-PROLYL)PYRROLIDINE - A POTENTIAL RADIOTRACER FOR PROLYL ENDOPEPTIDASE

The synthesis of the 4-[C-11]methylamino derivative of {N-[4-(4-Aminop henyl)butyryl]-L-prolyl}pyrrolidine (SUAM-1221), is described as a pot ential marker for prolyl endopeptidase for in vivo positron emission t omography studies. Direct methylation of the 4-amino derivative of SUA M-1221 (1) with methyl iodide provided a mixture of the LF-monomethyl (2) and 4-dimethylamino (3) derivatives which were separated by chroma tography. Methylation of 1 with [C-11]methyl iodide provided the 4-[C- 11]methylamino derivative of SUAM-1221, ([C-11]2), in 18 - 30% decay c orrected radiochemical yield after HPLC purification, with a specific activity >1700 Ci/mmol and a 40 minute synthesis time from end of bomb ardment.