N-(6,7-dichloro-2,3-dioxo-1,2,3,4-tetrahydroquinoxalin-5-yl)-N-alkylsulfonamides as peripherally restricted N-methyl-D-aspartate receptor antagonists for the treatment of pain.

A series of quinoxalinedione sulfonamides with potent NMDA receptor antagonist activity are discussed as potential pain therapeutics. The antagonists were optimized for oral bioavailability and decreased capacity to cross the blood–brain barrier.