Synthesis and Biological Activity of 1-Substituted 5-Oxopyrrolidine-3-Carboxylic Acids

1-Substituted 5-oxopyrrolidine-3-carboxylic acids were prepared via cyclization of 2-methylenesuccinic acid with aliphatic, aromatic, and heterocyclic amines. The synthesized compounds possessed analgesic and antihypoxic effects of varying strength. The analgesic activity was slightly greater for compounds with an aromatic or heterocyclic radical in the 1-position.