A competitive mGluR1 antagonist (Ki = 298 μM; IC50 = 1 mM for rat mGluR1α when challenged with glutamate); at concentrations from 10-300 μM, used to characterize the role of mGluR in LTP in the hippocampus in a model of learning and memory, the release of glutamate in Parkinson's disease, and the activity of mGluR implicated in fragile X syndrome