Potent group II/III mGlu receptor antagonist, with approximately 20-fold selectivity for group III over group II (IC50 values of 2.2 and 46.2 nM respectively). A much less potent antagonist at group I receptors in neonatal rat cortical slices (KB = 0.65 ± 0.07 nM). Also available as part of the Group III mGlu Receptor Tocriset™.