A series of novel aminoalkylindoles was synthesized in an effort to develop compounds that are potent agonists at the CB1 cannabinoid receptor and that are also easily labeled with radioisotopes of iodine for biochemical and imaging studies. 2-Iodophenyl-[1-(1- methylpiperidin-2-ylmethyl)-1 H-indol-3-yl] methanone (8, AM2233) had a very high affinity for the rat CB1 receptor, with most of the affinity residing with the (R)-enantiomer. ...