SYNTHESIS OF [2-C-14] FANTOFARONE OR 1-[4-[3-N-METHYL N-[3,4-DIMETHYLBETA-PHENETHYL] AMINO PROPYLOXY] BENZENE SULFONYL] 2-ISOPROPYL [2-C-14] INDOLIZINE

Sodium [1-C-14] isobutyrate : 1 was obtained by carbonation of isoprop yl magnesium bromide with (CO2)-C-14. From : 1 [1-C-14] isobutyryl chl oride : a was prepared, which through the successive actions of diazom ethane and hydrogen bromide gave rise to 1-bromo 3 methyl [2-C-14] 2-b utanone: 5. The latter lead to the indolizine : 6 which by a route pat terned after that used to make unlabelled Fantofarone gave the [2-C-14 -indolizyl] Fantofarone : 8 (specific radioactivity : 58.2 mCi/mMole) overall yield 9.9% based on [C-14] BaCO3.