3-APBT (former developmental code name SKF-6678), also known as 3-(2-aminopropyl)benzo[β]thiophene, is a monoamine releasing agent and serotonin receptor agonist of the benzothiophene group.

[2] 3-APBT produces the head-twitch response, a behavioral proxy of psychedelic effects, in rodents.

[2] It does not stimulate locomotor activity in rodents, suggesting that it does not possess stimulant-type effects.

[2][3] 3-APBT was developed by Smith, Kline & French (SKF) as a potential pharmaceutical drug in the late 1950s.

[1][4] The drug and its positional isomer 2-APBT were reported to produce various central nervous system (CNS) effects and to be useful as a "ataractics, psychic energizers, and analgetics".