Meta-Chlorophenylpiperazine
meta-Chlorophenylpiperazine (mCPP) is a psychoactive drug of the phenylpiperazine family. It was initially developed in the late-1970s and used in scientific research before being sold as a designer drug in the mid-2000s.
Source: Wikipedia — Meta-Chlorophenylpiperazine (CC BY-SA 4.0)