5-MMPA (Mephedrene) Powder 5-MMPA Powder, also known as Mephedrene, is a research chemical belonging to the phenethylamine class. The IUPAC name for 5-MMPA is 2-(5-methyl-2-phenyl-1,3-oxazol-4-yl)ethan-1-amine, and its CAS number is 24698-57-5. In its powder form, 5-MMPA appears as a fine white or off-white powder with a high level of purity, typically 98.0% or higher. This compound is highly sought after by researchers studying the effects of phenethylamines on the brain and behavior due to its potent and unique properties.