In recent years, considerable effort has been spent on the design, synthesis and pharmacological characterization of radiofluorinated derivatives of the 5-HT1A receptor antagonist, WAY-100635, for the in vivo study of these receptors in human brain with PET.(Pyridinyl-6)-fluoro-and (pyridinyl-5)-fluoro-analogues of WAY-100635 (6-fluoro and 5- fluoro-WAY-100635, 5a/6a) were synthesized as well as the corresponding chloro-, bromo ...