Imaging compounds

摘要

The invention relates to compounds of formula: (I) or a salt or solvate thereof, wherein: R¹ is -¹¹CH₂R⁵ or [¹⁸F]-C_1-4 fluoroalkyl wherein R⁵ is hydrogen or C_1-4 alkyl; R₂ is hydrogen or C_1-4 alkyl; R³ is halo; and R⁴ is halo, C_1-4 alkylthio, or C_1-4 alkyl; and their use for imaging central nervous system (CNS) receptors.