MDMA and the Indole Structure

[megamole]

Okay, let's rephrase: "I know of no entheogens/entactogens with an amine or amide function on an aromatic ring". The 4-amino and 4-acetamido derivatives of 2,5-DMA is for example fully inactive.

"Entheogenic" is such a subjective term! And surely you would agree that there are many non-entheogenic biologically active compounds worthy of interest. Perhaps you may find the following articles interesting:

European Journal of Medicinal Chemistry   (1996)   31    133-142.
European Journal of Medicinal Chemistry   (1999)   34    137-151.
Journal of Medicinal Chemistry   (1963)   6       519-524.
Journal of Medicinal Chemistry   (1978)   21   1    56-63.
Journal of Medicinal Chemistry   (1980)   23   2    154-162.
Journal of Medicinal Chemistry   (1986)   29   8    1406-1412.

Each of the them is a study of biologically-active 4-amino phenethylamines. Of particular interest to this discussion is the article from '86, in which the indole homolog of MDA is studied, which turns out to be, among other things, a potent MAO inhibitor at serotoergic, norandegenergic, and dopaminergic receptor terminals.

Also worth reading is the JMC article from '63, in which 4-dimethylaminoamphetamine was found to be a more potent anorexigenic compound than phenmetrazine (albeit somewhat weaker than amphetamine itself.)