NMDAR antagonist 1 is a potent and orally bioavailable NR2B-selective NMDAR antagonist. NMDAR antagonist 1 (Compound 5q) exhibits excellent neuroprotective activity. NMDAR antagonist 1 can attenuate Ca2+ influx induced by NMDA.NMDAR antagonist 1 can suppress the NR2B up-regulation and increase p-ERK1/2 expression.NMDAR antagonist 1 inhibits SH-SY5Y cells with cell viabilities of 75.8%, 80.0%, 84.4%, and 78.6% at 0.1 µM 1 µM 10 µM 100 µM, respectively.NMDAR antagonist 1 is a potent and orally bioavailable NR2B-selective NMDAR antagonist. NMDAR antagonist 1 (Compound 5q) exhibits excellent neuroprotective activity. NMDAR antagonist 1 can attenuate Ca2+ influx induced by NMDA.NMDAR antagonist 1 can suppress the NR2B up-regulation and increase p-ERK1/2 expression.NMDAR antagonist 1 inhibits SH-SY5Y cells with cell viabilities of 75.8%, 80.0%, 84.4%, and 78.6% at 0.1 µM 1 µM 10 µM 100 µM, respectively.