Reinvestigation of the synthesis and evaluation of [N-methyl-(11)C]vorozole, a radiotracer targeting cytochrome P450 aromatase.

Introduction: We reinvestigated the synthesis of [N-methyl-(11)C]vorozole, a radiotracer for aromatase, and discovered the presence of an N-methyl isomer which was not removed in the original purification method. Herein we report the preparation and positron emission tomography (PET) studies of pure [N-methyl-(11)C]vorozole.

Methods: Norvorozole was alkylated with [(11)C]methyl iodide as previously described and also with unlabeled methyl iodide.