Phenylisobutylamine, also known as α-ethylphenethylamine, ****Butanphenamine, B or AEPEA, is a stimulant drug of the phenethylamine class. It is a higher homologue of amphetamine, differing from amphetamine's molecular structure only by the substitution of the methyl) group at the alpha position of the side chain with an ethyl group. Compared to amphetamine, phenylisobutylamine has strongly reduced dopaminergic effects, and instead acts as a selective norepinephrine releasing agent. The dextroisomer of phenylisobutylamine partially substitutes for dextroamphetamine in rats. "Phenylisobutylamine" is in fact a chemical misnomer because isobutylamine itself contains a branched chain. The correct name after this style for this class of compound would be "phenylsecbutylamine".

Derivatives

A number of notable derivatives of phenylisobutylamine are known, including the following: • N,α-Diethylphenethylamine • BDB • MBDB • EBDB • 5-MBPB (5-MABB) • 6-MBPB (6-MABB) • 4-CAB (α-Et-PCA) • 4-MAB (α-Et-4-MA) • Buphedrone • N-Ethylbuphedrone • 3F-NEB • 4-Methylbuphedrone • Butylone (βk-MBDB) • Eutylone (βk-EBDB) • Dibutylone (βk-DMBDB) • Ariadne (α-Et-DOM) • 4C-B (α-Et-DOB) • 4C-T-2 (α-Et-2C-T-2) Additional derivatives with longer α chains also exist, for instance pentedrone, MBDP, pentylone, MDPV, and hexedrone, as well as others, like mexedrone. Whereas MDMA is a serotonin–norepinephrine–dopamine releasing agent (SNDRA), MBDB appears to be a highly selective serotonin–norepinephrine releasing agent (SNRA) and with significant preference for induction of serotonin release over norepinephrine release. The phenylisobutylamine counterparts of psychedelic phenethylamines and amphetamines, for instance MBDB (the α-ethyl homologue of MDMA) and Ariadne (the α-ethyl homologue of DOM), show greatly reduced or abolished psychedelic effects in comparison. This has also applied to α-ethyltryptamine (αΕΤ), which is non-hallucinogenic in contrast to α-methyltryptamine (αMT). In the case of Ariadne specifically, it may be due to reduced efficacy in activating the serotonin 5-HT2A receptor.