N-[omega-[4-(2-methoxyphenyl)-1-piperazinyl]alkyl]-2-quinolinamines as high-affinity fluorescent 5-HT1A receptor ligands.

We here report on the design, synthesis, binding affinities, and fluorescent properties of a series of serotonin 5-HT 1A receptor ligands, with N-[omega-[4-(2-methoxyphenyl)-1-piperazinyl]alkyl]-2-quinolinamine structure. Several of the new ligands displayed nanomolar affinity at 5-HT 1A receptor and good fluorescent properties. In particular, derivative 24 showed a favorable combination of 5-HT 1A receptor affinity ( K i = 0.4 nM), Stokes shift (excitation wavelength = 381 nm, emission wavelength = 455 nm), and quantum yield in ethanol (Phi = 0.45).