Pyrrolidine-2,4-diones with affinity to the N-methyl-D-aspartate (glycine site) receptor, Part II 5-arylidene-pyrrolidine-2,3,4-trione 3-oximes as NMDA receptor antagonists

A series of oximes deriving from 5-arylidene-pyrrolidine-2,3,4-triones and pyridine-2,3,4-triones has been prepared. The presence of the tautomeric ni trosoenol was proven in solutions of alpha-ketooxime 7a. The binding affini ty of the new oximes toward the N-methyl-D-aspartate (glycine site) recepto r has been measured as a basis for more detailed structure-activity relatio nship studies. Grime 13b showed the highest binding potency acting as glyci ne antagonist in nanomolar concentration.