A series of N-(2-phenethyl)cinnamides was synthesized and assayed for antagonism at three N-methyl-D-asparate (NMDA) receptor subtypes (NR1A/2A-C). N-(2-(4-hydroxyphenyl)ethyl)-4-chlorocinnamide (6) was identified as a highly potent and selective antagonist of the NR1A/2B subtype.