5-(2-Aminopropyl)-2,3-dihydro-1H-indene (5-APDI), also known as indanylaminopropane (IAP) and, incorrectly, as indanylamphetamine, is an entactogen and psychedelic drug of the amphetamine family. It has been sold by online vendors through the internet and has been encountered as a designer drug since 2003, but its popularity has diminished in recent years.

5-APDI acts as a potent and weakly selective serotonin releasing agent (SSRA) with IC₅₀ values of 82 nM, 1,848 nM, and 849 nM for inhibiting the reuptake of serotonin, dopamine, and norepinephrine, respectively. It fully substitutes for MBDB but not amphetamine in trained animals, though it does produce disruption for the latter at high doses.

Anecdotal reports suggest that 5-APDI is considerably less stimulating and euphoric than related compounds like MDMA. However, in combination with amphetamine, it is said to be virtually indistinguishable from MDA by recreational users.