Besonprodil
Besonprodil (CI-1041) is a drug which acts as an NMDA antagonist, selective for the NR2B subunit. It is under development as a supplemental medication for Parkinson's disease, and has been shown in animals to be effective in counteracting the dyskinesias associated with long-term treatment with levodopa and related drugs. References

NMDA receptor antagonists
Fluoroarenes
Piperidines