5-MBPB

5-MBPB is an amphetamine and phenylisobutylamine derivative which is structurally related to MDMA and has been sold as a designer drug. It can be described as the benzofuran-5-yl analogue of MBDB or the butanamine homologue of 5-MAPB, and is also a structural isomer of 5-EAPB and 6-EAPB. Anecdotal reports suggest this compound has been sold as a designer drug in various European countries since early 2015, but the first definitive identification was made in December 2015 by a forensic laboratory in Slovenia.
5-MBPB is similar in structure to compounds such as 5-APB which are claimed to be agonists of the 5-HT_2C receptor.
5-MBPB has been found to act as a potent serotonin–norepinephrine–dopamine releasing agent, with preference for induction of serotonin release over norepinephrine and dopamine release, and fully substitutes for MDMA in animal drug discrimination tests. Unlike 5-MAPB, it is a relatively weak serotonin 5-HT_1B receptor agonist.