Most phenethylamine, tryptamine, ergoline, etc. drug patents are expired and in the public domain.
Yes actually even almost all of them are.
I don't think it is widely known though, as even designer drugs/research chemicals that so far aren't patented yet, will usually become protected from becoming it ever.
So, like when they are described by forensical chemists, they become unpatent-able, not able to show up described in a patent at first.
I only know this as it happened to a friend of mine, who prepared several novel fluoromethoxyamphetamines, and wanted to patent them as psychotherapeutic invention drugs, and many other claims of a similar nature, psycholytic therapy and such...
His patent was still filed, I have linked it below, but had not applied successfully, due to the mentioned issue.
He was carrying that out purely as a hobby by the way, and while doing them himself, he soon started giving his products aways for free in psycholytic sessions to friends and patients who were recommend by them, but later on for sessions just for the drug use with his friends(actually they considered him as acquintance only, reason given below), yet still for free... but under the condition they use them still at his home.
Then his lab was busted soon after the filed application, and due to being one of the biggest drug labs ever in that certain german state, it was causing literally at least three dozen articles in the largest national newspapers countless else in the tiny local ones.
One was even called "biochemist testing drugs on friends", which indicates he drugged up people against their will... but he doing psycholytic therapy instead, with MDMA mostly but tried other substance too, when the patient was in for it of course.
It even was likely one of the largest designer drugs lab in private hands not doing commercial syntheses.
He once told me, to have made around 40% of his bibles, those being of course Pihkal and Tihkal... I saw proof of it(stil own a few of those proofs, like DOET, what the hell is wrong with anyone using that:
![Smiley :)](https://thevespiary.org/talk/Smileys/default/smiley.gif)
His suicide has also cause an half dozen article, being something like a celebrity, or maybe thus because it was the only barbiturate related death for like half a century?
Anyway, due to his suicide, I feel free to post his application here, as it contains of course the real name of him.
Here is the patent application of him...
https://patents.google.com/patent/DE102011015842A1/enHe would have liked to see it spread, even if the chemistry is all known very much to us...
But involves LiAlH4 reductions fluoro P2NP's though, something Joe only lately has described as being very, very rare, citing just two examples of it... these can be translated easily to unsubstituted LiAlH4 of course, as the fluorine there only causes to change the pharmacological aspects, not the chemical ones... (except the 2-fluoro analogue though, that acts just exactly like plain amphetamine).
I find that sad, as he was one of the last people influenced only by Shulgin instead of Breaking Bad, back then almost everyone pursuing drug chemistry with determination to want to invent new drugs, and most making meth instead only wanted to become cool drug cooks.
Back then, the most major influence before this series, was probably the dateline episode with strike, I would guess?
Nowadays, due to that damn series(never watched it and never will! It almost ruined the future of the hobby!), everyone who wants to pursue drug chemistry nowadays is itself drawn to make meth due to that series, as it has influenced the public view on the hobby more than anything else ever.
Just claiming to do chemistry as a hobby, even if it just is simple anorganic stuff or other non-drug related stuff, will get you a "are you making meth?" as immediate response from most of the people, not only in the americas but even the whole western world!