GSK189254 and its corresponding precursor GSK185071B were synthesized from 3- methoxyphenylacetic acid with 6-chloropyridine-3-carbolic acid or 6-chloronicotinamide in 8 and 7 steps with either 6% or 7% and either 14% or 16% yield, respectively.[11C] GSK189254 was prepared from GSK185071B with [11C] CH3OTf through N-[11C] methylation and isolated by HPLC combined with solid-phase extraction (SPE) in 50–60% ...