A selective mGluR1 PAM (EC50s = 0.39 and 0.36 μM for human and rat receptors, respectively) with no activity as a mGlu4 PAM (EC50 >10 μM); potentiates a response to glutamate in wild-type cell lines stably expressing mGlu1 and partially restores the reduction in glutamate-mediated calcium signaling in a mutant cell model of schizophrenia.