Agent: Purdue Pharma L.p.20120165337 - Tetrahydroquinoxaline urea derivatives, preparation thereof, and therapeutic use thereof: ile=US20120165337A1-20120628-P00002.TIF alt=custom-character img-content=character img-format=tif/>lkyl group, or lkyl-phenyl; R6 and R7, identical or different, are each a hydrogen atom, an alkyl group, alkoxy, or an alkyl-phenyl group; and R8 is a hydrogen atom