SYNTHESIS OF ISOTOPICALLY LABELED HYDRO-3-(N-PROPYL)-1H-BENZ[E]INDOLE-9-CARBOXAMIDE, A 5-HT1A RECEPTOR AGONIST

The title compound is a potent and selective 5-HT1A receptor agonist w ith clinical potentials for treating anxiety and depression. It has be en labeled with stable and radioactive isotopes to support ADME studie s in animals and human subjects. Its carboxamide group was labeled wit h C-14, C-13, or C-13, N-15, and O-18. To provide a radioligand for in vestigating the receptor binding characteristics of the compound, we a lso labeled it with tritium in the N-propyl group to obtain the high s pecific activity of 86.7 Ci/mmol.