Synthesis of radio-iodinated melatonergic agents

The synthesis of two 125I-labeled trisubstituted aromatic melatonergic agents is reported. N-[[2-[125I]iodo-5-methoxyphenyl)-1R, 2R-cyclopropyl]methyl] butanamide was prepared from the corresponding thallium salt and Na 125I in radiochemical yields of 13–45% (n = 3). High performance liquid chromatography separation of the two resulting radioiodinated isomers (8:2) from each other and the parent compound required the use of two different columns run in series. Synthesis of N-[[2-[125I]iodo-5-fluorophenyl)-1R, 2R-cyclopropyl]methyl] butanamide was prepared from the corresponding trimethylstannane precursor in radiochemical yields consistently in the range of 60–65% (n = 6). Copyright © 2002 John Wiley & Sons, Ltd.