ADX-47273 is a positive allosteric modulator of metabotropic glutamate receptor 5 (mGluR5) with EC50 values of 0.17 and 0.23 μM for potentiation of glutamate activity in HEK293 cells expressing rat mGluR5 and primary astrocyte cultures, respectively. It is selective for mGluR5 over rat mGluR1 and human mGluR1 and mGluR4 when used at concentrations up to 10 μM. In vivo, ADX-47273 (1 and 10 mg/kg, i.p.) increases ERK and CREB phosphorylation in the hippocampus and prefrontal cortex in rats. It decreases the conditioned avoidance response, apomorphine-induced climbing, as well as PCP-, apomorphine-, and amphetamine-induced locomotor activity in rats in a dose-dependent manner, indicating antipsychotic-like activity. ADX-47273 (0.1-50 mg/kg, i.p) improves recall in a novel object recognition test and reduces impulsivity in the 5-choice serial reaction time task (5CSRTT). It also enhances reversal learning in mice in the Morris water maze test.