I can see why you picked that particular halo, but any reason why the 3,4? I don't have the binding/efficy information in front of me; did this material stand out in some way?
I just re-read what Rectify suggested: 4 ethyl. It's interesting when looking at Pihkal that with the 3-carbon analogs (of the 2,5 dimethyloxy 4-alkyl) the potency goes down but the duration goes up. Would I be correct in thinking it's because they are more lipophilic?
Thinking back, I'm sure that 3-methoxy 4-alkyl amphetamines have been made in Russia. Reports said that the 4-methyl was sort of OK for an MDMA substitute but longer alkyls were just too low potency.
I'm just someone who finds the open-chain PEAs too physically taxing. If 4-Me or 3,4 methylenedioxy are known to have the right balance of releasing/reuptake inhibition for dopamine, serotonin & norepinephrine then it would be confirmation of the amine I would look into. Oxazine-rings have been sucessfully utilized in the past. One cannot help wondering if Mr. Fastandbulbous tried ring-substituted phenmetrazine analogs as part of his pHd?
I'm going to make a prediction - I predict 2-(3,4 methylenedioxy)-3-methyl morpholine will make a pretty good MDMA substitute. I'm not sure about the p-Me (even though it's more practical). I thought, from methedrone, that the p-Me offered a metabolic pathway for oxidation (it's certainly noticed in the metabolites) but it may not be.
That's a problem because nobody, however hardcore, would want MDMA-like activity for several days! The strongest morpholine was the 2-phenyl-4,4-dimethyl with a similar dose range to dextroamphetamine (Dexedrine for those old enough). It got quite a long way into research before it was discovered to be teratotoxic. It only occured at very high dose levels (the 100s mg/kg) but it was still considered enough to kill the project stone dead.
The oxazines seem to have enhanced dopamine over norepinephrine activity & don't produce much in the way of physical effects. They are, in addition, far less toxic & generally better tolerated. Of course, the bornanones are even better but they aren't likely to show up as RCs any time soon
Lastly, I don't know why the CH3 -> CH2OH ->COOH would be so toxic. Surely less so than the 3,4 di -OH as seen in the 'original' entactogen. Not GOOD, I appreciate, but then not SO bad. The 4 nitro is of academic interest if nothing else...