Patent ID: 8497260

Claim:
A compound Formula 1 and pharmaceutically acceptable salts thereof: wherein: R 1 is hydrogen; R 2 is hydroxy, C 1 -C 4 linear or branched alkoxy which is unsubstituted or substituted with hydroxy or fluorine; R 3 -R 4 are independently or optionally C 1 -C 4 linear or branched alkoxy which is substituted with fluorine; nitro; amino; C 1 -C 4 linear or branched alkylamino which is substituted with fluorine; or dimethylamino which is substituted with fluorine, and V, W, X, Y and Z are independently carbon or nitrogen, and at least two of V, W, X, Y and Z are nitrogen, where fluorine is in the form of 18 F or 19 F.