NMDA receptor antagonist 2 is a highly potent and orally active NR2B subtype-selective antagonist of the N-methyl-D-aspartate (NMDA) receptor. It exhibits remarkable binding affinities, with an IC50 of 1.0 nM and a Ki value of 0.88 nM. This compound finds valuable application in scientific investigations focusing on neuropathic pain and Parkinson s disease.