Synthesis of [82Br]bromperidol and preliminary tissue distribution studies in the rat.

A procedure is described for the preparation of [82Br]bromperidol with specific activity 440 muCi/mg. The incorporation of bromine-82 into the molecule was accomplished through Brackman and Smit's modification of the Sandmeyer reaction, during the last step of the synthetic route. This involved the formation of a complex between Cu82Br2 and nitric oxide gas in acetonitrile, which was then allowed to react with 4-[4-(aminophenyl)-4-hydroxy-piperidinyl]-1-(4-fluorophenyl)-1-butanone (aminoperidol, 10) to give [82Br]bromperidol in about 1.5 h. Cupric 82Br]bromide was prepared in situ from K82Br and CuSO4.5H2O. The radiochemical and chemical yields for the preparation of [82Br]bromperidol from K82Br were 10.4 and 12%, respectively. Preliminary tissue distribution studies with the labeled bromperidol in the rat showed that the uptake of radioactivity by the liver, brain, kidneys, and the lungs was very fast and was in the declining phase in the latter organs 15 min after iv administration.