Synthesis, radiosynthesis, and biological evaluation of carbon-11 and fluorine-18 (N-fluoroalkyl) labeled 2beta-carbomethoxy-3beta-(4'-(3-furyl)phenyl)tropanes and -nortropanes: candidate radioligands for in vivo imaging of the serotonin transporter with positron emission tomography.

2beta-Carbomethoxy-3beta-(4'-(3-furyl)phenyl)nortropane (1) was synthesized along with the N-methyl (2), N-fluoroethyl (3), N-fluoropropyl (4), and N-fluorobutyl (5) derivatives. The binding affinity for each compound to the human serotonin, dopamine, and norepinephrine transporters was determined using transfected HEK-293 cells. Radiolabeling and microPET brain imaging studies were performed with [(11)C]1, [(11)C]2, and [(18)F]3 to determine their utility as in vivo imaging agents.