Irampanel (

INN Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway; before the advent of motorized transportation they also provided accommo ...

, code name BIIR-561) is a

drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via insuffla ...

which acts as a dual

noncompetitive antagonist A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of recep ...

of the

AMPA receptor The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (also known as AMPA receptor, AMPAR, or quisqualate receptor) is an ionotropic receptor, ionotropic transmembrane receptor for glutamate (iGluR) that mediates fast synapse, synap ...

and neuronal voltage-gated sodium channel blocker. It was under development by

Boehringer Ingelheim C.H. Boehringer Sohn AG & Co. is the parent company of the Boehringer Ingelheim group, which was founded in 1885 by Albert Boehringer in Ingelheim am Rhein, Germany. As of 2018, Boehringer Ingelheim is one of the world's largest pharmaceutical ...

for the treatment of acute stroke/

cerebral ischemia Brain ischemia is a condition in which there is insufficient bloodflow to the brain to meet metabolic demand. This leads to poor oxygen supply or cerebral hypoxia and thus leads to the death of brain tissue or cerebral infarction/ischemic stroke. ...

but never completed clinical trials for this indication. Irampanel was also trialed, originally, for the treatment of

epilepsy Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrical ...

and

pain Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, ...

, but these indications, too, were abandoned, and the drug was ultimately never marketed.

Synthesis

The condensation between benzamidoxime 13-92-3(1) and

methyl salicylate Methyl salicylate (oil of wintergreen or wintergreen oil) is an organic compound with the formula C8H8O3. It is the methyl ester of salicylic acid. It is a colorless, viscous liquid with a sweet, fruity odor reminiscent of root beer, but often a ...

(2) in the presence of NaOEt under microwave irradiation generated oxadiazole 9349-24-9(3). Subsequent alkylation of the hydroxyl group with dimethylaminoethyl chloride 07-99-3(4) and NaH in dioxan produced the target aminoethyl ether (5).

References

AMPA receptor antagonists Anticonvulsants Dimethylamino compounds Neuroprotective agents Oxadiazoles Sodium channel blockers Abandoned drugs {{anticonvulsant-stub