New heteroaryl-spaced phosphono α-amino acids are competitive NMDA antagonists with analgesic activity

The synthesis and the NMDA receptor binding affinities of α-amino-3-(phosphonomethyl)-2-naphthalene-propanoic acid, α-amino-3-(phosphonomethyl)-2-benzofuranpropanoic acid, a series of substituted (R)-α-amino-3-(phosphonomethyl)-2-quinolinepropanoic acids, (R)-α-amino-3-(phosphonomethyl)-1,8-naphthyridine-2-propanoic acid and (R)-α-amino-3-(phosphonomethyl)-1,6-naphthyridine-2-propanoic acid are reported.