Potent metabotropic glutamate mGlu1 receptor antagonist (IC50 = 6.3 μM at rat mGlu1a). Displays ≥ 40-fold selectivity over other receptors: mGlu5, mGlu2, mGlu4a (IC50 > 300 μM), NMDA and AMPA (IC50 = 250 μM). Neuroprotective in cultured murine cortical cells and rat hippocampal slice cultures in vitro. Reduces the volume of ischemia-induced brain infarcts in rats following systemic administration in vivo. Purity 99%. MW (observed): 215.23