Synthesis and evaluation of an 18F analog of forskolin for imaging adenylyl cyclase (original) (raw)

We prepared two¯uorine containing carbamate analogs of forskolin as potential agents for imaging adenylyl cyclase in the living brain with positron emission tomography. Both compounds display high in vitro af®nity for adenylyl cyclase. The radiosynthesis of 7-(2-[ 18 F] uoroethyl) carbamoyl forskolin from an imidazolyl carbamate utilizes [ 18 F]¯uoroethyl amine, prepared by a novel method employing rapid deprotection and requiring no distillation. The brain uptake in rats and monkeys of 7-(2-[ 18 F]¯uoroethyl) carbamoyl forskolin is too low to be an effective imaging agent for this second messenger system.