The base compound of the MDxx class is 3,4-methylenedioxyphenethylamine (MDPEA), and the prototypical agent of this class is 3,4-methylenedioxy-N-methylamphetamine (MDMA; "ecstasy").
The foundational component of the MDxx series is 3,4-methylenedioxyphenethylamine (MDPEA), and MDMA (ecstasy) represents a typical example within this category.