(R)- and (S)-5-hydroxy-2-(dipropylamino)tetralin (5-OH DPAT): Assessment of optical purities and dopaminergic activities

Racemic 5‐hydroxy‐2‐(dipropylamino)tetralin (5‐OH DPAT), a potent and selective dopamine (DA) D2‐receptor agonist, was resolved into the enantiomers by a new method. The enantiomers of 5‐OH DPAT were determined by chiral ion‐pair chromatography using N‐benzyloxycarbonylglycyl‐L‐proline as the counter ion. The enantiomeric purity of (R)‐5‐OH DPAT was found to be > 99.7%. The ability of the enantiomers to change the rat brain DOPA levels was evaluated in vivo. The results indicate that (R)‐5‐OH DPAT is a weakly potent DA D2‐receptor antagonist.