According to the literature, no 5-ethoxy tryptamines has been tried in humans. But it is sure an interesting area to investigate.
http://rhodium.lycaeum.org (http://rhodium.lycaeum.org)
Especially since they're not scheduled, and the 5-position seems to be the equivalent of the 4-position in phenethylamines:
(quoting http://www.phc.vcu.edu/rag/serotonin/ (http://www.phc.vcu.edu/rag/serotonin/)
On the basis of our earlier SAFIR work, and using a calf 5-HT1D receptor preparation, we felt that extension of a 5-position substituent on a tryptamine scaffold should ultimately result in the desired selectivity. That is, both receptor populations can accommodate bulk at the tryptamine 5-position but, the two receptors being different, it seemed logical that these two regions of bulk tolerance should be different. Indeed, we were successful in identifying NOT, or 5-(nonyloxy)tryptamine. We found that as the length of the 5-position substituent increased, 5-HT1D selectivity began to increase. Unfortunately, affinity at both populations began to decrease as the alkyl chain was extended. A nonyloxy substituent was found to be optimal. NOT was found to bind with high affinity and with 100-fold selectivity for 5-HT1D versus 5-HT1A receptors.
Other 5-position substituents were examined, including arylalkyloxy derivatives, and analogs were prepared that displayed > 400-fold selectivity for 5-HT1D versus 5-HT1A receptors. We also found that the 5- position oxygen atom is not required for 5-HT1D binding and that shorter chains are tolerated in the absence of the oxygen atom.